overheating

[gearhead11]

need suggestions, i have an 88 r currently running a cr head gasket and an inline cooler(20 fin) and a stock radiator with maxima cool aide. and it still runs hot, sometimes it overflows just a little, but then sometimes it starts boiling back into the overflow bottle. its a xc bike with a ct midrange pipe, fmf q2 silencer, 67.5mm wiseco some port work(mostly just a clean up job)
any suggestions?

[250r rider 88]

if you are willing to spend the money a PWR or similar aftermarket alluminum radiator would help a little

you can find good ones on ebay for around 325-400

and you already have an inline cooler that would have been my only other recommendation

what temp range are you seeing?

[gearhead11]

havent checked yet but after doing a search on this forum i think i have figured out that it is the head gasket

[Aceman]

Originally posted by gearhead11
havent checked yet but after doing a search on this forum i think i have figured out that it is the head gasket

I'd say you're on the right track. You shouldn't be overheating with a stock cylinder like that.

[hang1p]

I ran a 330 with a stock rad and never overheated. When i went to the 350 i got a Afco Dual Pass and with the 401 me and Jon370 are running fans.

[hang1p]

fan

[custom R]

how does your fan set up work doess it run off a battery or off the stator im thinking of putting one on mine it gets pretty hot when im doing alot of hill climbs in the trails

Where did you get your fan ?

[CorvetteZ06]

i have had 310 pro-x motors, and now im running a PC2000, and have had LRD 300's, and never had any over heating problems. hows your water pump? the stock sytem should be more than effecient for a stock jug.

[machwon]

I'd check the radiator cap or just get a new one. Lots of times those can be an issue.

[gearhead11]

checked the pump about 2 mounths ago when i put a new clutch in it.
also have a 30lb radiator cap but havent tried it yet, i was told it could cause problems b/c of to much pressure. stock cap is 16-20lbs

[All250R]

When it's cold, crack open the radiator cap and see if you smell exhaust. A blown gasket or cracked head will often spill oil and exhaust into the coolant system.

Another test is after the cool, start the motor and give it a few cracks on the throttle. Feel the hoses with your fingers as you start and rev the bike. The hoses will stiffen quickly if there's a leak.

I cracked a head once and went through this whole thing with my overflow bottle dumping coolant. If you're exchanging coolant in the engine you're damaging the bore with coolant washing the oil off the piston. Basically, check that you don't have a head problem asap.

[machwon]

Originally posted by gearhead11
checked the pump about 2 mounths ago when i put a new clutch in it.
also have a 30lb radiator cap but havent tried it yet, i was told it could cause problems b/c of to much pressure. stock cap is 16-20lbs

Yes, the 30 lb cap will fix it. I've used one on my 250R for years. You will need good radiator hose clamps if you are having a presssure problem, otherwise it will just blow the hoses off. Keep in mind your radiator level will need to drop some due to the thermal expansion of the coolant. It should't go below the fins in the radiator though.

[gearhead11]

well i figured it out the head gasket was blown on the inside, when it was cold coolant would seep inside the cylinder, but when it got hot compression would actually seep past the gasket into the water jacket and caused the build up of pressure.

but suprisingly the cylinder and piston and rings actually survived. ive gone to a mixture of 75% water with 25% coolant and water wetter just for kicks. thanks for all the suggestions guys