I should have known this wouldn't be easy. Had everything done, or so I thought. Apparently the head gasket blew. It was one I reused years ago so that doesn't surprise me. Bad part it I must have put the wrong radiator cap on it when I put the motor in. Probably 20 of them lying around the not so organized shop. It was too tight and the radiators swelled up when the head gasket let go and the big one in the back split open.

I found a Polaris outlaw 500 radiator with a fan I had bought for something else and never used. It wouldn't fit in the original spot so I mounted it up on the cage.

Got a new head gasket a couple days ago and thought it would be a walk in the park. I have done it plenty of times. Everything was going fine till I put the cam back in and found out the timing chain is shot. Luckily I have gaskets and five more engines. One of them is bound to have a good chain in it.

Gray...........you funny!

Ya gotta love it...

It runs. I'll have to wait till tomorrow to see if it's fixed.

If I had a dollar for every time I screwed up my engine..... I could buy a new engine ! Glad you got it back together.

This has been a fun thread to read. My boy has a Roketa GK13B and at Valley Of Fire Bash he blew the head gasket. I decided to have Tom SYC port and polish and deck the head. I just got it back last week. Put it on this morning and while tightening down the bolts on the valve cover one of them snapped off. Errrr, it is flat stuck off in the head.

I decided to let it roll, I will have to see if it seeps oil. But after getting everything hooked back up that little CN250 fired right up. Absolutely amazing.

My boy is anxious to rip around on it.

Good luck G-Ray

You might want to fix that before running it too much. You have the cycling of the valve train pushing on that cover.

I blew another one. At least i ordered two. I think I got it this time. Best I can figure I had a air bubble in the cooling system. The radiator I used didn't have a nipple for the small bypass line that comes off the thermostat so I just capped it off. I think that was a bad idea. I made an adapter and hooked it up to the radiator hose right at the radiator, changed the gasket again and everything seems to be working fine now. I had to use a different head. Evidently it got so hot the epoxy in the intake port on the Endrigo head came apart and a chunk of it went through the motor. It didn't do any damage but it's missing. Now I have a Syc head, Endrigo cam and 260 psi compression hahaha. I hope it holds together.

260psi; Crap

I think I'm pushing the limits and my luck hahahaha

I know you probably know this already, but I have found the acorn nuts in some cases bottom out on the studs before you get a good torque. I quit using them and went to regular nuts with sealer on the threads.

I thought about that and made sure it didn't happen. For whatever reason when I started it up after I put the first head gasket on it it got hot enough for the pipe to glow red just idling in the shop. Then I started seeing the black sealant from the head gasket in the radiator. Second time with the bleed line hooked up it took a long time for it to warm up and the gasket held through a spirited test drive.

Are you talking about the line that comes from the carb going back to the radiator? I have run with those blocked off with it causing any problems.

Wow the exhaust glowing red with it just idling?

Yes the line that goes to the carb. I didn't think it would be an issue but it's the only thing I could come up with that might have caused it. Some strange things happened. First, both the HH radiators swelled up and the bottom tube in the one in the rear split and it lost all the water. I think that was because I put the wrong cap on it. The spring is longer than the others I looked at and it feels like it binds when I put it on. Second, after I put the radiator up high and capped off the bleed line on the thermostat the head gasket was blown. I can't say when it happened, before or after I changed the radiator. Third, I changed the gasket and it blew right there idling before I even drove it. Finally, after changing the gasket again and hooking that small line up everything seems to be working fine. My theory is there was a big air pocket in the the engine and without that small line that bypasses the thermostat it had no way out till it was too late.

Is that the little fitting on the neck of the radiator? When I put a different rad on my gk it only took about quart of anti-freeze. I let it run for a minute,and the water level didn't change. That nipple had a hose on it that was plugged. I took it off,and my AF disappeared , I was able to put almost a full gallon in it after that ! So far so good !
Hope it keeps going for you!

Yep, the HH radiator had two fittings. The top one right under the cap went to the reservoir. The one below that had a hose that originally went from the top of the thermostat housing, through the carb and to the radiator. That was the one missing from the new radiator that I just plugged off at the thermostat.

I am just about done, I hope. I need to dig around and try to find a 40 pilot. I know I have one somewhere but it wasn't with the rest of my jets. The 42 in there now is too big. I put some lighter pillow springs in the clutch and it hooks up much better now. I have to say it's pretty mean for a 250. I vividly remember now why I put the Polaris struts on the first one I had. I hope it will hold together till June hahaha.

G I brought those spare Polaris struts I had down to your place last fall didn't I?. I can't remember nothin in my old age.

I was afraid it was too much and it was. 260 psi + pump gas = yet another blown head gasket. it lasted one good ride but today it decided to give up. I'm going to put the stock head back on it so the kids can ride.

I backed down to 235psi on the blade just so I wouldn't blow crankcase gaskets.