Has anyone investigated if any V-Force reed valves will fit the twinshock TY250?

(with or without modification)

I'm pretty sure the reed valve in the TY250 is the same as a DT250 of the same age which may make it easier to find out

Hi JC2,

Are in to a ongoing VF3 conversion of TY175 (as well as finalized TYR)

Have chosen V382A with trials set up.

*you do need to grind or polish off ~0.1-0.2mm per LH/RH of inlet..

Will not say anything about performance yet and the engine will not be up and running until...2012-13..The question is not if but how much improvement gained vs std cage 1974.

My cage step 3 improvement VF3 of TYR works fantastic!

Step 1. Yam std cage/Boyesen (-Jap engineering status per late -70

Did some further looking into the v-force reed block & found that the RD's have the same part number for the reed block as TY250 twinshocks, that lead me to a thread on 2 stroke world about fitting v-force reeds into RD400s.

There is 2 different versions of the V382 for YZ85s, the V382A which has an offset hole & the V382S-A which is a v-force 3i set up & has the central hole that would be required to need no modifications, if you got the V382A with the offset hole then part number AG462A is the part needed for the central hole. In the RD400 the inlet port has to be widened to allow fitment but hopefully the TY250 has a bit more space at the sides

I'll be looking at getting the V382S-A set up in the near future

Edited April 28, 201412 yr by tony27

Finally got around to spending some quality time in the garage with a Dremel.

The V-force reed is quite a bit wider than the standard TY block & only pushes in about 8mm, doing some measuring showed that at the tips the intake needs approximately 1mm per side ground out, reality is that the port has draft which is needed for casting.

Thanks for the info Tony. I'll be interested to hear how engine performance compares to one with standard Yam reeds

This is the extent of the work I did to the port to make it fit, I marked around 40mm into the port & started gently grinding there on both sides & checked often to see how far the reed would fit in.

 

After getting the reed to slide in with the holes lining up I blended the step out to the edge of the sleeve so there is no sudden change in shape. 

It will be a while before I get to try the motor out as it looks like I'm going to need to get the fork sliders machined to fit a bush at the top to get rid of the play I can feel & help keep oil in them. Motor will be a lot more powerful than it was as it was so worn that I could turn it over by grabbing the end of the crank after removing the flywheel, main bearings were shot as well. I think I may have put up a couple of photos of the work I did to the clutch cover to remove all signs of the oil pump during the rebuild