Freestyle Trixstar, unknown freestyle build.

[BlackMerry]

Hi All,

After doing some online research on this forum, I recently bought my first Jetski. A Trixstar freestyle ski with a lot of upgrades (according to the previous owner).

Now I'm really interested in the items that are used in my ski. Also for maintenance it's very helpfull to understand my own ski.
Hopefully you can recognize the parts of this build.

The information I have about my ski.

Items I'm sure about:
-Trixstar Full Carbon Hull
-Aluminium pole with carbon chinpads
-Carbon exhaust + waterbox
-Yamaha 62T crankcase (62T00 Y-1 casted on the case with next to it a circkle with OU18 casted)
-RRP Trim system
-5 or 6mm spacer below cylinders (hard to measure but I think it is 6mm)
-Mikuni corp double carburator, but size unknown
-MSD ignition spark plug caps (not sure what type of ignition is mounted)

Items told by previous owner:
-6mm stroker
-~1000cc engine (bigbore+6mmstroker) so when bore is 92mm there is 984cc? (according to this tread?)
https://www.x-h2o.com/threads/yamaha-62t-61x-displacement-vs-bore-stroke-combinations.5136/ ?


On both crankcase and head there is written ''ml''. I already did a research, but cannot find any cyl head looking like mine.
Also the cylinder cases are not the standard 61x or 64x castings. but cannot find cylinders which have the same look.

Is there a way i can check the CC of this engine quickly?
What kind of head gasket is used on this kind of cylinder/head combinations?
Do you know whats the brand/name/type of the cylinders and cyl head?

Many thanks!

 

[BlackMerry]

A few more detailed pictures of the engine.

 

[przemek2f]

Try measuring the piston stroke with a caliper through the spark plug hole. You can also read the markings on the piston through the spark plug hole.

 

[Quinc]

See the silver plate between the cylinder and the cases. That is needed with a stroker crank.

 

[jetfreak78]

ML = Michael Lorenz, a german Tuner. He build good engines back in the days. Not sure, if he is still in business.

 

[WFO Speedracer]

See the silver plate between the cylinder and the cases. That is needed with a stroker crank.

Yep if you measure the plate it is 1/2 of the stroke added so 3mm plate = 6mm stroke

 

[BlackMerry]

Thanks for the first replies.

I measured again and im 100% sure that the silver plate below the cylinder is 5mm thick.

This means i have a 10mm stroker?

I have checked the text on the pistons.
It says 8229D150, which means wossner 90,5mm pistons out of a Honda CR500.
Is it commen that they take pistons out of dirtbikes?

When i check the stroke/bore/cc chart this means 1003cc. Which is as described by the previous owner.

Even better, there is room for a extra overbore if something will happen with to the cylinder walls.

Thanks a lot for the help!

 

[BlackMerry]

If someone still recognizes the cylinder and cylinder head type/brand it would be really helpfull

 

[waxhead]

If its a 6mm and the clearance has all been found by jacking the cylinder. You are going to have some damn high port timing right there

 

[BlackMerry]

If its a 6mm and the clearance has all been found by jacking the cylinder. You are going to have some damn high port timing right there

Is there a way to manually rotate the crank? Then i would be able to check the stroke length.

 

[waxhead]

Yes reach down and rotate the cloudier with you hand. Disconnect the battery before please

 

[wydopen]

Yes reach down and rotate the cloudier with you hand. Disconnect the battery before please

Pretty sure that was a typo. You can rotate the driveshaft coupler by hand.

 

[BlackMerry]

Thanks,

I measured stroke.
Measurements are taken from spark plug surfces.

Bottom measurement 99.5mm
Top measurement 31.4mm

Subtracted is 68.1mm. Which means I have oem stroke instead of 6 or 10mm.

I understand the comments about lifter plate is always 1/2 x added stroke.

How does this work with my engine?
I have a 5mm spacer plate below the cylinders and I do not understand why it is there. I thought that this spacer plates means that is was a stroker engine.
Maybe it is done because the cylinders that are used are not high enough for 68mm stroke?

Thanks in advance!

 

[WFO Speedracer]

Measure the total height of the cylinder, from top of spacer plate to head gasket surface .

No one here really knows what you have there , some measurements will give clues though.

 

[wikstromm]

Probably the cylinder is machined down and added the spacerplate to raise port times

 

[Big Kahuna]

Pic shows 62T cases.

 

[BlackMerry]

Measure the total height of the cylinder, from top of spacer plate to head gasket surface .

No one here really knows what you have there , some measurements will give clues though.

I measured the cylinder height (without spacer plate) and it is 119.0mm.

I think it is important to know the brand/type of cylinder that is used. Or is there an universal head gasket that fits 90.5mm bore cylinders?

Thanks!

 

[WFO Speedracer]

Most of those head gaskets are special order but they can make one for any size bore fairly quickly. 119 mm is stock cylinder specs so the cylinder has not been cut.

 

[przemek2f]

The cr500 pistons are 5mm taller than the 62t pistons. There is a plate under the cylinder to compensate for this. This is a standard 850cc BigBore mod

 

[WFO Speedracer]

So stock stroke and the plate makes up for different pin placement in the piston ?