<< I'd also like to add that the carbs are the same stock year to year. >>




My bad, when my friend got his 86' it had a round slide on it, I assumed it was OME. Sorry for the misinformation.

 

<< There are no round slide carbs in the Fourtrax line, the 3 wheelers had some but the quads never.

The clutch lifter/assembly was the best in 89. You can buy this kit and install on any year. Fibers/steels were the same.

The 86-87 have adjustable camber a-arms, the 88-89 don't.

They all have the same bore/stroke and in stock form are all 246cc. I don't know why people keep saying otherwise.

The carbs changed slightly every year, from PJ5 to PJ7, etc. They are interchangable.

Any year cylinder will work on any year bottom-end. Any year head will fit any cylinder.

There is no key-switch on the 86. All other years have them in stock form.

There is no bad year; they're all great! >>



I thought you had to use a spacer plate depending on what year cylinder you put on what year bottom end. Don't they have different port heights?

Plus, the 86 has no intake bridge, the later models do.

 

Spacer plate question and combinations it allows:

'86-'89 bottom &amp; '86 rod = any top end with '86 piston

'86-'89 bottom &amp; '87-'89 rod = any top end with '87-'89 piston

'86-'89 bottom &amp; '87-'89 rod = any top end, spacer plate, '86 piston

Common reason for using a spacer plate has to do with using the '86 piston which goes up to 0.140 over for aftermarket suppliers (ProX goes to .120, but Wiseco goes to .140). '87-'89 pistons are only made up to .080 over.

Using spacer plate also increases crankcase volume, which lowers the primary compression ratio. There're some tuning reasons for this, but it'd stray from original question in post.

 

I appologize for my misleading information about the bore/stroke.
I was wrong.

The 5mm longer rod does not affect the stroke.

-Matt

 

The only time you need a spacer plate using stock cylinder/pistons is

using rod from 87-89 model (5mm longer than 86)and then using 86 model piston (wrist pin located 5mm lower in piston).

A lot of questions can be answered easily just by looking through a Clymer manual. Spend the money and get one.

Also, really want to learn the 250R? Really?

http://pub20.ezboard.com/bhondatrx250r

 

How much is the weight difference between all the years i know the 86 R weighs at 328 but i dont know about the other years. Which year would be best for Dunes and MX.

 

The 88/89's might be a few lbs lighter.
ERIC