I have an 86 250r and the engine is all stock. It just doesnt get the rpms like it should, it has been this way since I got it. It will only rev so high then it drops off, and it doesnt rev that high at all. I thought it needs a rebiuld so I borrowed my brothers compression tester. I have 165 lbs of compression. Does anyone know how much I should have? Do I need to rebiuld? This is on the original stock piston and rings.

 

Pull you plug, and post what it look's like on here

 

Its a dark brown. Its not too rich, just a little.

 

i would pull your carb and check you reeds because if they are chipped at all then you revs will suffer so check them out see if that helps

 

Maybe there is a problem with the CDI.

 

hmmmmmm, well fo one, hes running the worng plug(br6es) it should be a br8es. I know it is just a different heat range but, everyone runs the br8es or b8es, why change it?

hes gonna check his reeds.

he may have a bad bearing, maybe thats why it revs and then slows down because of the heat and expansion.

who knows, hes checking the reeds, then if it still does it hes ripping the top end off.

what would you guys do if you had to take the top end off?

he wants to change the rings only, but hes got plenty of compression.

it would kind of suck if he did that and put it together and it did the same thing.

wwhat would you guys change?

I would buy a base gasket, head gasket, piston, rings, wristpin and wrist pin bearing and new wrist pin circlips.Just to be safe. Peace of mind is always priceless.

if he rebuilds the top end, he will be able to inspect the play in the crank and connecting rod.

lets hope for the best for him!

I hope its the reeds

 

I will probably check the reads tommorrow. I dont want to rebiuld it yet, because money is an issue and my parents want me to save my money to buy a truck within the next few months. So if the reeds dont look so good I will try that but if that doesnt cure it its gonna have to wait until after I get a truck. If that does work then I will ride it the way it is until after i get a truck and then rebiuld my top end. My topend only has about 40 hours on it, should the bearings and all that be bad already?

 

MY BET WOULD BE THE REEDS ALSO. IF THEIR OLD AND STIFF THEY DONT OPEN UP ALL THE WAY.

 

I checked everything over and it all looks good, I pulled out the reeds and they look good, I dont know about the carb floats and stuff but if that was off wouldnt it run funny in other areas of the rpm range?

 

IF THOSE REEDS ARE MORE THAN 5 YEARS OLD I'D GET NEW ONES ANYWAY. THEY DONT COST THAT MUCH. JUST BECAUSE THEY LOOK ALRIGHT DOESNT MEAN THEY ARE AS FLEXIBLE AS THEY NEED TO BE. THEY CAN BE THE ROOT OF A LOT OF 2 STROKE PROBLEMS. IF YOU HAD FLOAT PROBLEMS GENERALLY THEY LEAK OUT THE OVERFLOW. CDI'S CAN MIS FIRE BUT USUALLY THEY JUST WONT RUN. I STILL THINK ITS YOUR REEDS.