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You are here: Home > Lambretta > Lambretta tuning > Tuning options for 200cc engines using TS1 barrels
    

Tuning options for 200cc engines using TS1 barrels

TS1 CYLINDER KITS

The basic standard cylinder kit offered by the manufacturer comprises of an aluminium Nicasil plated reed valved cylinder.
This then has a larger inlet port than you would expect if you are used to seeing cast cylinders, the inlet port has an extra port above it, this is a boost port, part of the advantage of a reed valve engine.
The inlet port is made larger to house a 4-petal reed valve, which requires a new inlet manifold and now the carb sits on the opposite side of the scooter.
A special Asso piston is required that is pre machined to give a full 360 degrees inlet opening period.
The transfer ports appear to be larger than a cast cylinder as they are now bridged to give four ports in stead of two, The transfer passages now have larger feeds. The exhaust port is much larger in size and now has a new shaped round exhaust flange.
The kit then requires a machined cylinder head.

The TS1 200 kit uses a 66mm piston and the TS1 225 kit uses a 70mm piston apart from that there is very little difference between the two.

PROS: In standard form the kit is quite well thought about in its design but has its faults! The TS1 cylinder should give more spread of power, better acceleration and better cooling! It will travel for longer with fewer hassles compared to a cast cylinder. The cylinder plating is harder wearing and longer lasting.
CONS: The kit requires a full expansion chamber to gain its full potential although a Clubman system could be used but restricts the power out put, what ever exhaust used a new exhaust flange needs fabricating. The kit is designed to use an open bellmouth carb, because of the lack of room under the panel it is difficult to filter the air. Long term this will cause the piston and cylinder to wear out!

GENERAL TS1 INFORMATION

The smallest carb that can be used with the standard inlet manifold is a 28mm Amal or 30mm VHSA Dellorto. (Using the Imola inlet manifold you could use carbs down to 24mm to no great advantage, as the physical size of the carb is too large to fit a filter, the smaller carb could work with low revving engines)
Amal carbs foul on all side panels and requires a large hole cutting in the panels. Amal carbs need their power jet blanking off and main jet increasing accordingly.

The Dellorto carb fits under the panel with a minor modification.
Using larger 34 - 39mm carbs is usually over kill even on a stage 3 tune as the cylinder doesn’t flow air quick enough for them to work perfectly.
Dellorto carbs need blue printing to increase fuel flow as a TS1 motor can use more juice than the carb can supply.

A fast flow fuel tap is required on all TS1 engines.
As the carb now exits the opposite side any battery tray would have to be removed.
The reed valve assembly was originally offered with no rubber sealing area these valves used to eat reed petals regularly. The later reed valve was an improvement but the rubber coating was more like plastic and tends to chip off causing even more problems.
To add to this when fitted into the cylinder the reed stops and reed petals block off the boost port therefore losing some advantage of the boost port. In some cases the reed petals could touch the piston!
The new inlet manifold has a tendency to touch the frame especially using the longer series 2 or sports shock absorber. The inlet manifold comes out at such an angle that in some cases the carb in a vertical position fouls the toolbox.
For most touring applications the cylinder port timings are a little too high as they were made more for racing.
The cylinder head that comes with the kit is usually reprofiled incorrectly which gives a false squish clearance and compression ratio.
The factory setting uses a 0.5mm head gasket this tends to blow and fail.
Running a TS1 on a standard crankshaft and main bearings will result in a failure. A failed crankshaft could terminally damage the cylinder, as there are no rebores!
The only porting mod required with the kit is having the casing transfer feeds matched to the kit.
Early 200cc 66mm pistons are not strengthened and tend to break!
A TS1 tends to have more power out put than a cast engine and also tends to vibrate more so no short cuts should be taken inside the engine, any weak links will be found they are not as forgiving as a cast engine. Power out put increases, most engines are 20-horse power up wards at the rear wheel, and most average 22 – 24HP this is bordering on needing a 6-plate clutch to prevent clutch slip.

TS1 CYLINDER KITS BY MB DEVELOPMENTS.

MB Developments have looked at the disadvantages over the years and improved upon them.

MB Developments looked at the reed valve problem and found a Yamaha one to fit, this is more reliable on its rubber coating and have never had a failure in 13 years.
Yamaha reed valves are slightly longer so a 5mm-reed packer was made to fit between the reed valve and the cylinder therefore spacing it away from the boost port.
This then created a problem as the standard inlet manifold hit the frame before the shocker was fitted.
To get around this MB Developments remanufactured a new inlet manifold and reshaped it for improved gas flow, altered to improve clearance from the frame and repositioned so the carbs cleared the toolbox.

A Yamaha racing reed block was found at a later date and was an improvement over the earlier standard item.
A larger variety of reed petals are also available, MB Developments recommend the two stage Boyesen reed petals to give the best advantage of all.
Amal carbs became a bit primitive in their use, added with the fact they touch the panel MB Developments were one of the first to introduce the Dellorto VHSA and VHSB flat slide carbs, mainly because they fit under the panel work.
We found that the 34-36mm carbs were physically too large but still fitted under the panel, as time went on we phased out the larger carbs for the 30-32mm smaller version with no power loss but much improved the engines all-round performance.
MB Developments found out that flat slide Dellortos are faulty from the factory, which results in fuel starvation, All flatslide carbs need blue printing to prevent this.
To spread the power MB Developments now machines the base of the cylinder, this lowers the port timings, which then makes the scooter more ride-able and brings in power lower down.
Another advantage of this conversion requires a 1.5mm head gasket, which is less prone for failure!

Apart from special cylinder heads that we offer, MB Developments only use the improved Indian cylinder head, this has less chance of distortion, with our machining techniques correct squish clearance and safe compression ratio is gained for maximum speed with reliability.

MB Developments have dynoed all the oppositions expansion chambers many times, we found some offered bottom end power with lose of horsepower and revs, others offer lack of bottom end power with a gain in top end power and revs.

We developed our own bottom end pipes and top end pipes beating the opposition as we did it. We then came to the conclusion that given the road conditions, fuel used and the majority of uses of a TS1 Engine, i.e. fast road touring and motor way use. We developed a mid range pipe called the Dev-tour to cruise at 70 mph (approximately 7000rpm) with useable power below that and then having accelerating and overtaking power giving the best of all worlds. The pipe was good around town and was good one up or two up! Also building in the advantages of ungroundability, easy fitting whatever cylinder used, machined or with packing plates, using 4 or 6 plate clutches.

With the above conversions MB Developments believe we offer the best TS1 engines in the world!

TS1 200 / 225 TUNES

MB Developments tune TS1 cylinders slightly different compared to cast iron cylinders.
TS1 cylinders are already tuned as standard. This doesn’t mean they can not be improved upon and tuned further.

STAGE 1. TS1 ROAD (TOURING) TUNE

Cylinder ports are flowed and polished, exhaust port is widened.
The casings require matching to the standard cylinder transfer feeds.
The cylinder base could be machined to lower port heights this then spreads power output, when this is done a 1.5mm cylinder head gasket is required, this is also an improvement as standard head gaskets tend to blow. This is tune is our most popular one.

STAGE 2. TS1 ROAD / RACE TUNE

Inlet port is flowed and polished, boost port is widened and the exhaust port is widened and raised.
The casings require matching to the standard cylinder transfer feeds.
The cylinder base could be machined to lower port heights, this then spreads power output, when this is done a 1.5mm cylinder head gasket is required, this is also an improvement as standard head gaskets tend to blow.

STAGE 3. TS1 RACE TUNE

Inlet port is opened, flowed and polished.
The boost port is widened.
The exhaust port is widened, raised and opened up to race porting spec.
The transfer feeds are opened to the maximum safe limit.
The casings need to be opened to the larger size.
Some times it is an advantage to weld the casings to strengthen around the transfer area.

t_dsc00914.jpg - 9728 Bytes Stage 3 tuned inlet port.
It has been widened, lowered and flowed.
t_dsc00918.jpg - 9728 Bytes Stage 3 tuned boost port with widened secondary transfer ports.
t_dsc00919.jpg - 9728 Bytes View up the barrel showing the tuned inlet and boost port.
t_dsc00920.jpg - 9728 Bytes Stage 3 transfers are tuned to their absolute maxiumum without going to the extreme of welding the cylinder.
t_dsc00921.jpg - 9728 Bytes Occasionally the engine casings need welding for re-inforcement as opening out the casing transfers to match the ones on the cylinder can leave the casings vulnerable to cracking.
t_dsc00922.jpg - 9728 Bytes Stage 3 exhaust port widened with increased port timings for high power and higher revs.
t_dsc00923.jpg - 9728 Bytes The diameter of the exhaust port at the flange is increased.

STAGE 4 AND 5. TS1 SPECIAL ROAD AND RACE TUNES

MB Developments offer a wide variety of tunes and conversions to TS1 cylinders using alloy welding, Iron liners, re-nicasiling or ceramic plating.
Improved quality pistons can then be used with the benefit of one, two or three boost ports.
Various con rod / piston combinations are available to make stronger, longer lasting, higher powered increased capacity conversions.
Conversions could include longer 60, 61, 62, 63, 64 or 65mm stroked crankshafts. Some alloy welding around the transfer area could be used as an advantage to these race spec cylinders. Occasionally extra inlet feeds into the casings are used also. Cylinders of this type have been known to reach 40-horse power at the rear wheel.

TS1 REPLATING SERVICES

NICASIL PLATING

Nicasil plating is the original plating process used by Gilardoni who manufacture the TS1 cylinder, it is excellent for reliability and hard wearing.
If your cylinder is damaged Gilardoni won’t repair your cylinder.
There is a company in the UK that offers the service but I find it wears out quicker than the original and because of this we recommend Ceramic plating.

CERAMIC PLATING

th_dsc00032.jpg - 9728 Bytes
This picture shows a tuned TS1 cylinder, replated the MBD ceramic way.
The coating resembles chrome rather than the white finish you would think.

th_dsc00103.jpg - 9728 Bytes
Another view of another TS1 exhaust port. This is a Taffspeed tuned
barrel we ceramic plated after it wore out.
Through the exhaust port you can see the style of tune Taffspeed used to do - a massive boost port (compared to standard).
th_dsc00104.jpg - 9728 Bytes
The ceramic plated TS1 barrel with the Taffspeed exhaust port shape.
Looking closely at the picture above you can see the bottom edge of the port is slightly lop-sided.
It's a minor detail but with Mark's engineering eye he wouldn't have left it like that!!

All cast iron and alloy cylinder kits can be ceramic plated, a coating similar to nicasil or chrome plating.
It doesn’t require any more rebores, it has less friction and dissipates heat quicker and in theory it is harder wearing than the nicasil coating.
Ceramic plating can be used as a replating service to repair damaged or worn out TS1 cylinders (or any alloy kit) or could be used when choosing an improved piston / con rod set up (this usually requires some welding and reporting).
It is ideal for long lasting cylinder kits, full race spec cylinders or kits already done that may be worn out and on its last rebore therefore repairing the bore.
Chrome piston rings can be used in ceramic plated cylinders.
For cylinder kits requiring extra cylinder height modified ports we recommend Iron liner conversions.

IRON LINERS

Iron liners are ideal to repair or modify a TS1 cylinder.
Iron liners allow oversized rebores. Iron liners are good to repair broken spigots on very badly damaged alloy cylinders.
By using iron liners ports and cylinder heights can be moved to accommodate different pistons other than standard.
To our knowledge there is not a Japanese style piston that goes straight into a standard TS1 cylinder that is worth using. These pistons have different compression heights and smaller ring peg spacings. MB Developments don’t re-peg or slot piston rings they go wrong!
Using a standard TS1 piston in an iron liner conversion is a waste of time as there are no oversizes available! The piston used determines what needs to be done to the cylinder. There could be 2 ways to do liner conversions.

1. BASIC. Fit a liner to a standard TS1 cylinder. The piston and con rod would depend on what loose cylinder packing plate and head gasket is to be used.
2. MBD WAY. The original boost port is welded up as all other piston rings drop into the port.
1, 2 or 3 new boost ports are cut into the cylinder this depends on the ring peg spacing of the new piston.
The compression height of the piston and gudgeon pin size determines what con rod is required.
Most conversions would require a loose cylinder packing plate; instead an oversize plate is welded to the base of the cylinder then machined off afterwards, therefore no loose packing plates!
Doing this usually means slightly larger transfer feeds can be used, this may require welding to the casings. To do away with any type of head gasket the iron liner would be extended and made into a spigot, the head would need machining to suit, this then gives the advantage of locating the head perfectly.
Tuning to the cylinder can be done after the liner is fitted.

Standard TS1 cylinders

Standard TS1 cylinders
A B C
Piston conversion TS1 TS1 Yamaha
Cylinder Capacity (cc) 200 225 200
Standard piston size (mm) 66 70 66
Oversizes available? no no no
Repair oversizes available? no no yes
Iron liner required? no no no
Ceramic plating required? no no no
Cylinder base packing plate required? no no no
Con rod length required (mm) 107 107 107
Gudgeon pin size (mm) 16 16 16
Crankshaft stroke (mm) 58 58 58
Crankshaft stroke options (mm) 60 60 60

Iron linered TS1 cylinder conversions

D E F G
Piston conversion Yamaha Yamaha Yamaha Honda
Cylinder Capacity (cc) 200 210 225 225
Standard piston size (mm) 66 68 70 70
Rebore oversizes available? yes yes yes yes
Iron liner required? yes yes yes yes
Cylinder base packing plate required? no no yes yes
Con rod length required (mm) 110 110 115 115
Gudgeon pin size (mm) 16 18 18 18
Con rod type required Yamaha Piaggio Rotax Rotax
Crankshaft stroke (mm) 58 58 58 58
Crank area machined groove required? no yes yes yes
Crankshaft stroke options (mm) 60 60,61 60,61,62,63 60,61,62,63

Ceramic plated TS1 cylinder conversions

H I J K
Cylinder Capacity (cc) 200 225 225 230
Standard piston size (mm) 66 70 70 71
Repair oversizes available? yes yes no yes
Ceramic plating required? yes yes yes yes
Cylinder base packing plate required? no yes no no
Con rod length required (mm) 115 115 115 115
Gudgeon pin size (mm) 16 18 16 16
Con rod type required Yamaha Rotax Rotax Yamaha
Crankshaft stroke (mm) 58 58 58 58

MB Developments have used over the years many piston and crankshaft stroke conversions, what are listed are what we consider the best.

PROS AND CONS FOR MB DEVELOPMENTS TS1 CYLINDER CONVERSIONS

A. TS1 200cc, Vertex or Asso
PROS. Cheapest TS1 cylinder kit, vibrates less than a 225 kit.
CONS. Piston tends to fail with the older pistons, slightly down on power compared to a 225 kit.

B. TS1 225cc, Vertex or Asso
PROS. Second cheapest kit, has more power than a 200 kit, has a stronger piston kit.
CONS. Vibrates more than a 200 kit, piston tends to fail on 25HP + engines.

C. TS1 200cc, Yamaha IT 175
PROS. Excellent piston and rings either genuine or Wiseco, excellent con rod conversion, doesn’t require boost port moving, possibly the smoothest running TS1 cylinder kit.
CONS. Expense, requires a Yamaha con rod swap.
UPDATE June 2001; we have found that both genuine and Wiseco pistons to fail regularly. Both rings can spin over or pasted their ring pegs! Causing terminal damage! We are in the process of repairing cylinders with the Prox type pistons, to date we think we have cured the problem.

D. TS1 200cc, Linered Yamaha IT 175
PROS. Similar to kit C, Easiest kit to do, no major machining required prior to linering. Oversized pistons available to 68mm when required, good conversion to repair damaged cylinders, excellent con rod conversion.
CONS. Expense, requires iron liner fitting, requires a Yamaha con rod conversion.
UPDATE June 2001; we have found that both genuine and Wiseco pistons to fail regularly. Both rings can spin over or pasted their ring pegs! Causing terminal damage! We are in the process of repairing cylinders with the Prox type pistons, to date we think we have cured the problem.

E. TS1 210cc, Linered Yamaha YZ250 piston
PROS. Excellent piston and rings in genuine or Wiseco, oversized pistons available to 70mm when required, excellent con rod conversion, good conversion to repair damaged cylinders.
CONS. Expense requires iron liner fitting, requires Piaggio APE con rod conversion.

F. TS1 225cc, Linered Yamaha YZ250 piston
PROS. Super light piston for race use, oversized pistons available to 71mm when required, excellent con rod conversion, good conversion to repair damaged cylinders, has produced some of MB Developments highest horse powered engines 30-37 HP.
CONS. Expense requires iron liner fitting, extra boost ports, cylinder packer welding on, requires a Rotax micro light con rod conversion, requires casings opening out for the larger big end pin, the Wiseco piston can create long term problems due to its light weight design, Genuine pistons ring pegs fall out!

G. TS1 225cc, Linered Honda CR250 piston
PROS. Excellent piston and rings in genuine or Wiseco, oversized pistons available to 71mm when required, excellent con rod conversion, good conversion to repair damaged cylinders.
CONS. Expense requires iron liner fitting, extra boost ports, cylinder packer welding on, requires Rotax micro light con rod conversion. Requires casings opening out for the larger big end pin.

H. TS1 200 – 210cc, Ceramic plated Yamaha IT 175 piston
PROS. Same as C and D. But can use oversized pistons to clean up damaged bores and can give up to 210cc.
CONS. Same as C and D. Requires ceramic plating and has no oversizes.

I. TS1 225 – 230cc, Ceramic plated Yamaha YZ250 piston
PROS. Same as F. But can use oversized pistons to clean up damaged bores and can give up to 230cc.
CONS. Same as F. Requires ceramic plating and has no oversizes.

J. TS1 225 - 230 cc, Ceramic plated Honda CR250 piston

th_dsc00030.jpg - 11326 Bytes This shows the tuned inlet port using 3 boost ports. The reason there are 3 is that we need to move the ports to suit the existing ring pegs.
MB Developments don't like to re-peg pistons so we have to weld up the existing boost port and cut in 1, 2 or 3 new ones depending on which piston is used and where the ring pegs are.
th_dsc00031.jpg - 11153 Bytes View showing the polished stage 2 inlet with 3 boost ports.
th_dsc00033.jpg - 9979 Bytes Transfer and boost port layouts.
th_dsc00034.jpg - 10480 Bytes The modified Wiseco Honda 71mm piston.

This cylinder uses the Honda CR250 piston at 71mm with a 115mm Rotax rod on a standard 58mm crank giving 230cc.
PROS. Same as G. But can use oversized pistons to clean up damaged bores and can give up to 230cc.
CONS. Same as G. Requires ceramic plating, extra boost ports, cylinder packer welding on and has no oversizes.

K. TS1 230cc, Ceramic plated Kawasaki Jet Skis 440 big bore piston.
th_dsc00380.jpg - 10480 Bytes Race engines work best with a centre plug head.
Note the locating peg holes.
This head and barrel kit went to Vince Chu in the USA who is topping his class in the ASRA (American Scooter Racing Association) championships.
He actually uses this barrel on his ROAD bike.
th_dsc00381.jpg - 10480 Bytes The MBD TS1 inlet manifold tuned then matched and flowed to the MBD Yamaha reed block.
th_dsc00382.jpg - 10480 Bytes MBD full race spec 230cc ceramic plated cylinder showing the extra boost ports that we use.
This conversion uses a 71mm Jet Ski piston and requires a 1.5mm head gasket. We put pegs through the head and gasket into the cylinder to make sure it is all lined up as the piston protrudes from the top of the barrel at TDC.
th_dsc00383.jpg - 10480 Bytes The same cylinder viewed from the base showing the transfer feeds opened to their maximum.
th_dsc00384.jpg - 10480 Bytes View of the inlet port - matched, opened and flowed, showing the three boost port feeds.
With reed valves we need to use pistons with 360 degree inlet timing, this requires the Jet Ski piston to be modified.

PROS. Uses an oversized piston to clean up damaged bores, uses maximum safe piston size giving largest cc’s.
CONS. Expense, requires ceramic plating and has no oversizes, requires a Yamaha con rod conversion.

MB DEVELOPMENTS TS1 CYLINDER KITS

It has already been mentioned what is available for all TS1 cylinder kits.

The most popular kit that MBD do is our stage road touring tune.

We use the standard TS1 225 cylinder and piston, the cylinder base is machined to lower both the transfer and exhaust ports which spreads the pulling power, also by doing this a fat 1.5mm head gasket can be used making the cylinder to head seal more reliable!

The cylinder ports are tuned to suit, usually for touring giving more pulling power.
We use the Yamaha racing reed block with the race petals that come with it. A 5mm packing plate is required and a MBD inlet manifold which is polished.
An Indian cylinder head is reprofiled and compression ratio set to give maximum reliability, this set up runs very happily on unleaded fuel!

This tuned kit is more rideable set up this way and gives more power over the standard kit.

This engine when run on a dyno can vary in horsepower, depending the exhaust used! This is covered already in the gearing spec sheet. Basically the exhaust controls how a cylinder works and how the power comes in.

We have dynoed the tuned TS1 kits many times, in one of our latest sessions we ran a stage 2 touring spec kit over 80 times with different exhausts!

Horsepower altered from 19 to 28hp showing that an exhaust makes a big difference!

Part of this exercise was to test as many different types of exhausts as were available.
Some of the tests were to try and find a retro style 80’s exhaust for future production.
This involved testing various old 80’s expansions popular in their day!
Although nothing startling came from these pipes, what became evident was they were not far off the pace of the modern expansions.

The worst exhaust was actually the pipe already fitted with the scooter, this was a Kegra that only dynoed at 19hp. On the road was nothing sparkling but drove beautifully and our customer loved the scooter.
Another Kegra pipe was tested and gave 22hp with good revs high up in the rev range.
Our Devtour gave the best spread of power with 24hp and was only beaten by an experimental version of the Devtour.
One of our race pipes gave 28hp, other pipes hovered around 21 – 22hp some with a good spread and some were peakier!

What came from the test backed up our other tests and feed back from customers.
We have developed the stage 2 touring kit for over 10 years.
It has proved to give the best spread of power and total reliability.

MBD have striven to produce a complete package for the TS1 done our way!
Carburation can vary from what you want as mentioned earlier.
MBD recommends a flat slide VHSA 32mm carb for most applications.
You can go smaller if you want, or gain more speed with a larger carb.
If using any of the flat slide Dellortos they need what we call blue printing as the carb physically can not supply enough fuel compared to what the engine can use!
All our carbs have this done before sale!
If you haven’t had this done then get it done!
It will save you pounds in the long run.
MBD have seen plenty of blown motors for want of this little modification and a change of needle valve!

To my knowledge MBD are the only dealer offering this service!
So if your jetting is all to cock and jetting varies with fuel tank load, don’t be fooled that its just your jetting! It may be! But there’s always the fuel flow problem!

ALWAYS use a full race crankshaft with quality bearings.
It goes with out saying use an electronic ignition points can not take a TS1 for long!

THE TS1 CYLINDER PACKAGE

th_dsc00684.jpg - 10480 Bytes The MB stage 1 and 2 TS1 225cc cylinder package, showing all the parts that come with the kit.
The same parts come with the stage 1 and 2 kit.
The only difference is porting spec on the cylinder.
A stage 1 tune has the exhaust and inlet port modified to pull as a touring conversion.
The stage 2 has inlet, exhaust, transfer and boost port modifications to suit faster engines.
To be honest there isn't a lot of difference between the stage 1 and 2 but the stage 1 is the MB Developments preferred tune for touring, it can still reach 26hp with the right exhaust.

 

This kit usually returns 22 – 24 horsepower, it can give up to 60mpg, we have had them do over 10,000miles with no problems, the Devtour has peak power at 6000 - 7000rpm and will over rev to 8500rpm limiting the engines revs for reliability.
We recommend 5.22:1 – 4.52:1 overall top gear ratios depending on how you drive, this should give a true top speed of between 80mph and 93mph.
But more importantly it will be drive-able, ride-able, reliable and fun, one up or two up!

LONG STROKE CRANKSHAFT OPTIONS

PROS. By using a longer stroke crankshaft the cc of the engine increases, this then always increases the engines torque and pulling power and speed!
CONS. The longer the stroke extra vibration occurs. Fitting these crankshafts usually require some of the casing removing to allow the con rod to clear. In some extreme cases welding is required at the back of the casing for added strength.
At the moment off the shelf long stroke 60 and 62mm crankshafts are not very good they tend to be faulty and cause long term problems.
When using a 58mm crank with an eccentric crankpin and Rotax rod, 60 or 61mm strokes can be gained.
When using a 60mm crank with an eccentric crankpin and Rotax rod, 62 or 63mm strokes can be gained.
When using a 62mm crank with an eccentric crankpin and Rotax rod, 64 or 65mm strokes can be gained.
These can be only used in conjunction with 18mm pistons.
MBD have developed excellent racing long stroke crankshafts, from 58 to 60mm using a special crankpin, these cranks can use either Yamaha, Ape or Lambretta race rod kits. With either 16 or 18mm pistons.
58 to 60mm stroke would add approximatly 6-7cc to the engines capacity.
60 to 62mm stroke would add approximatly 7-8cc to the engines capacity.
This may seem small but makes a vast difference to the engines characteristics.

Please E-mail us with any questions or comments.