how do i tell what year my engine is?!?

[2fittyr]

I bought this bike a couple months ago and the kid told me it was an 87 but the frame says its an 86, but the motor has no vin on it and now i have the motor torn down and i dont know whay rod kit or piston kit to get because they differ between the 86's and 87's, i have the old reciepts and the first time he built the top end he bought parts for an 86 but the second time he bought parts for an 87, is there any other way to tell what year the motor is or can i just measure the rod and go by that?

[robyone]

If your planning on replacing the rod, then make it what ever you want. 86 had the short rod & 87-89 had the long rod.
Most people use the long rod, but there are some die hard short rod users also. If you decide to go with the short rod , you will need an 86 piston.

[JTRtrx250r]

OEM shortrods say KA4 on them , I think the longrod is HA2(but double check, I might bne wrong about the longrod

Good Luck !

[beerock]

the best long rod crank is the OEM 88

[Rich250RRacer]

Originally posted by beerock
the best long rod crank is the OEM 88

87-89 share common a part number (13300-hb9-770) so any year long rod OEM crank is fine.

[2fittyr]

so if i get a long rod kit do i have to get an 87-89 piston kit and gasket kit?

[robyone]

yeah, go with the 88 set up...rod & piston.

[Eddiesanders250]

You still can use an 86 piston with the long rod. You need to get a spacer plate tho.

[2fittyr]

thanks yall that really helped

[rockman]

You still can use an 86 piston with the long rod. You need to get a spacer plate tho

what are the pros/cons of using the 86 piston with the 87 crank, thats the setup i use just wondering what the difference is. it was already on the bike.

[slick250]

There is not a huge advantage, but with the spacer plate you get more overall volume in your crankcase, which means more fuel and air available to your top end.
I have had both, and the short rod engines rev a little quicker on the top end, but the long rod engines will pull harder down low and have a flatter torque curve.

I see you are from Topeka. I live in Hays. Do you ride the dunes (Little Sahara), much? How about Milford lake?

[rockman]

actually i haven't been to waynoka YET. Milford is on the list but we haven't made it out there, i have a friend who rides there and from what he said it doesn't sound like it justify's the drive. but we still want to go eventually. We used to ride at perry but its soo rutted now you can't hardly ride. osawatamie is pretty good but they are closed around this time of year due to deer season.

[beerock]

Originally posted by Rich250RRacer
87-89 share common a part number (13300-hb9-770) so any year long rod OEM crank is fine.

YES they may share the same part # but they were slightly different. and the 88 was best. i believe they changed the crank shielding from year to year