87' cylinder on a 85' 250R?

[MorningWood]

I just bought a brand new 85' 250R cylinder,piston, and head for my trike. I just blew a head gasket on the old head and wanted to replace the whole top end with my new parts. The shop called me today and said I have a 87' 250R long throw rod and cylinder installed on it and I cant use my new parts I bought. They also said I'm on my last bore and they will try to hone it and put a new piston and my new head on the old 87' cylinder. If not, they will try to find me another used 87' cylinder. Should I rebuild the crank back to stock and use my new stock parts or keep the 87' mods?
Any one have any sugestions?


:confused:

[200x_Basket]

i think all you need is a spacer plate.

[Mr. Richard]

ok i had to check my book before i said anything,,,there are lotsa ways to do this,,,, the only difference between long and short rod motors is the piston,,,,, so here we go!!!
all of these combo's are with your long rod bottom end,,,,,,

85 cylinder with stock piston,,,,, you need the proper spacer plate,
85 cylinder with a stock 87 trx piston bolt on and go..
87 cylinder which you have everything is 87 lets ride,,,
87 cylinder with a 85 piston ,, spacer plate too

i recomend you (if the bottom end is good ) buy a 562ps wiseco piston and go riding,,,, with your 85 cylinder,,, no spacer,,,

if the bottom is bad rebuild it short rod then put your new top on and go riding

do you know that wiseco goes to .140 over for the short rod motors too

all honda 250r cyilnders are the same bore and stroke stock that is ATC AND TRX 85-89

[200x_Basket]

how about the differences in port timing???

[MorningWood]

Thanks for the helpfull info Kasey! I will relay this info to my mechanic and see what he has to say about those options. Trying to get it done before Thanksgiving weekend in Glamis.
:headbang:

[MorningWood]

So all I need is a spacer plate to bolt my new 85' stock cylinder,piston and head to my long throw rod or buy a 562ps wiseco piston and install to my new 85 cylinder with no spacer? Sweet!

)