Overheating item

[JasonB]

Doing some woods riding on my 500. First real trip out for my 500r, and first real 2 stroke 500 machine experience. 40 minutes into the ride i got hung up on a tree and stalled the bike, at that point I heard it boiling the coolant and the overflow bottle was even steaming. I was running it hard in some tight trails and it was really my first experience w a 500 cc 2 stroke. I don't think I had it running too lean but why else would it overheat?

88 cr500 motor
39pwk 45pilot 170 main
Custom pipe
Boysen reeds

[bigpower]

Ok, so what kind of day was it, what was the temp? Above 80f? How tight war the trails, ATC, 3 wheeler, I'm thinkin at the least 30 inches. How long you hung up on the tree and trying to get loose before it stall?

What you using for rads, bro? That would be the first place I would investigate. Gotta remember, you're putting a bunch more load on the engine with those 3 fat tires than us 2 wheel knuckleheads, so if you're using some old 250R rads, you might not have the cooling capacity. A good upgrade for your app would be looking into some of those oversize Chinese rads they sell on the bay for CR500, and then seeing what you'd have to do to fit em. It prolly would be more patients than difficult, and look pretty trick on your already trick machine. Think I've been payin 85USD for a set, and theyre awesome as far as keepin my bike cool.

As far as your jetting contributing to your problem
Every application is different, and looking at what youre running, in what youre running, I say most definattely you're are a bit lean.
Again, you're putting on more load with the trike than we with the bike, so judging by youre location and elevation, I'd go up to a 175 main and work back from there, and probably a 48-50 pilot. Give yourself some airscrew, what I mean is, run enough pilot to give yourself 2 turns of adjustment. That way you're covered for most the temp extremes you're likely to encounter down there.

All I can think of

[Rhino89523]

Mine boils out the first 5 minutes on the first pull out of my house every time. It finds a level at about the top fins of my radiator and usually keeps it right there. I don't have an overflow tank. I run a heavy duty cap that helps some but I throw coolant every time.

[Kuma]

What condition is your water pump? 88 has mag which d get trashed. Overflow bottle might help and get some air flow, I have had times when my bike gets hot riding the dunes, this would be on a slower paced ride with the wind at my back, air speed near zero through the radiator.

[JasonB]

it was probably about 80 or so outside, not too hot but still warm. The trails were tight for the machines we were on, no speed to get air over the rads. I had been lugging it in 1st gear pretty hard around trees and both my rear tires caught a tree and killed the engine instantly. I freed the bike and was about to kick it back over and heard the boiling, so i let her sit. after 10 minutes i opened the rad and topped it back off with water from my camelbak.

guessing it just got hot because of the riding conditions etc.

I am running the stock 250R rads, considering switching over to using a cr500 frame so i can run the better rads and also not have to jimmy rig and exhaust system.

I am looking to tear the motor down in the next month; i miss shifted into 2nd and it started making some great noise when sitting in N after that. Besides, the bike could probably use a freshening up. I have no idea what the condition of the water pump is either,

[atc Sanchez]

Mine runs hotter than 250r, with the500 frame. I think its the traction
after a ride fins always showing under rad cap
I know about the large capacity rads but not to jack but your thread (jason) but...

For the lower speed ridding does removing the fins diverters on the rads help air flow, i'm not talking about the dumbo scops, those black plastic mounted to the rads things

Thanks

[JasonB]

youre good man, i dont have those on my rads. I just have the brackets that hold them and then the rads themselves. I thought i popped a rad at trikefest this year because it started spraying coolant but it turned out to be a bad hose. anyhow, i have run it without any of those guards/fins on it and havent had issues yet. I dont MX or go through alot of mud so I dont worry about the rads clogging up either. I do want to hook a temp guage up so I can see where I am at, i miss not having that on this bike like I do on the 310 (250R).

[Kuma]

Are you running the shrouds that scoop the air into the rad?
the other fins will protect against rocks from bikes in front, I'm pretty much only in the sand and don't run them but they are getting kinda thin from all the sand blasting.

[atc Sanchez]

So the black fins are rost guards states the nube
My 89 has the red dumbo scoops i know those are critical

And if you wana talk about sandblasting try an ATC my bike needs frame repair

[Kuma]

if your frame is getting sand blasted that much, glue a piece of thin rubber to it, maybe even try to paint with plasticoat.

[jbsleddin]

What the fuck is a dumbo scoop? A rad shroud??? Yeah, they're pretty important.