i have a 86' 250R with a stroker crank, ESR spacer plate, on alky with a 44mm lectron, Duncan head.....thats as much as i know about the bike....i just bought it and on top end, wide open it makes a metal to metal clanking noise at full throttle. The motor feels to be "loose" and the top end is good with great compression...im running a check on it in a min. and i will fill you in on the psi. but the bottom end feels to be loose....im new with this 250R and any help would be appreciated.

Where can i find a stock or nearly stock 250R motor that runs good....preferably not crate

 

the help level is wayyyy down my ankles somebody PLEASE....

 

You said you thought it was something in the bottom end, but i dont really have an idea about that. detonation could sound like a "metal to metal clanking noise," however, that would involve the top end.

 

You might be hearing piston slap which obviously is not good but the only way to determine what's going on is to remove the cylinder and check your clearances and inspect your cylinder wall for scoreing. At the same time you can check the play in your crank and your rod bearing. I've never ran an R on alcohol but I know they are a bitch to keep jetted properly.

 

hmmm, rod bearing?

Just too hard to diagnose without hearing the thing run... sorry

 

Rod bearing. I lost one on my R while running alky. THe alky is very hard on bearings and seals. Your purging the motor with gas rite? Mine was so bad that all the needle's in the bearing went through the motor and destroyed the piston. It made noise on the top end and a klankling noise at ilde.

 

im about ready to order a new dome for my head and put it on gas..im tired of this BS..but hey good news it ran good yesterday...really good...My 250 has severe mood swings...

 

I think that is what you will find with R's on Alcohol, they run great some days and like **** others. I know some fellas that drag race them at Little Sahara and they said they are always having to rejet and adjust their carbs. I have an ESR 310 motor with a 38 Airstryker jetted with a 200 main and I never have to touch it, whether it's 60 degrees out or 90, it's an awesome combination.