Engine Overheating

[maxwell]

Hey guys. I tried searching but only came up with a few irrelevant searches for this.

My bike has been out of commission for a couple months now anyway, and i never really thought about it before, but....


my bike was always fussy when i'd ride in the summer. like, if i'd be out on a ride and had to stop for gas, she wouldn't start again until i sat for a good 10/15 minutes and let her cool down a bit. is this normal? i always figured that it was just a common problem problem with aircooled bikes riding in warm weather. but from the reading i've done recently, these bikes are apparently relatively reliable, even in hot weather.

i figured i'd ask you folks - should i have been worried about my bike getting this hot in the summer? if so, what are common problems associated with these bikes overheating? what should i look for to help diagnose my problem (if it's a problem at all?)

thanks guys. btw, it's a 78. bs38's. open dragpipes. forgot the jetting offhand. not looking for an exact diagnosis, of course - just looking for some hypotheticals

 

[angus67]

Are your cylinders painted? Some paints keep heat in. Maybe its running lean?If its jetted stock with open pipes and pods, its prolly lean. What oil you running?
If you rebilt the head, did you replace the large orange o-ring that goes in the groove between sleeves and fins? oil could creep up between there and prevent good thermal transfer to the fins.

 

[maxwell]

Did not rebuild the head. i believe i'm currently running 10-40? maybe 20-50? and as far as a lean condition is concerned, i don't THINK so, but I could obviously be wrong lol. I'll let you know how she runs when i start her up again. i had her running right for maybe ten minutes after i rejetted her before she started fucking up. then again, who knows - maybe my dicking around with the jets and air fuel fixed the problem completely. hmmm.

 

[littlebill31]

Are you kickstarting it or using the electric start when it doesn't fire up?

 

[DogBunny]

maxwell:
How are you measuring temperatures?
I make XS650 thermometer-dipsticks if you don't already have a way of telling what your engine temperature is.
http://www.handspiral.com/ThermoDipStick.htm

 

[5twins]

Maybe your coils are crapping out. Many times, when coils go bad, they only act up when they get hot. That would explain the need to let it cool before it will start easily again.

 

[XSLeo]

Dogbunny's thermostick is a very good way of keeping track of the oil temps. A very good product, I like mine.
Another thing is a noncontact thermometer. I like item # 93984 from Harbor Frieght.
Handy to carry and use. 4 inches long, 2 wide, 3/4 thick, has a lanyard.
Head temps at the spark plug around 270-290. A bit less on cylinders, oil around 200-220.
A oil cooler drops both temps by about 40-50 degrees.
Leo