ssanddemon

A damp & dirty air filter is the most likely cause of the problem. As airflow gets restricted, it will make the motor run rich.

This is real common on all bikes, not just shees due to the tiny size of the brake fluid openings in the system; they are just too small to let bubbles escape easily. The best thing to do is buy an inexpensive hand vacuum pump from your local auto parts store. Hook up the vacuum line to the brake bleed nipple, open the nipple and apply vacuum. This will forcibly suck the air out. Another thing I have heard is to take a thin rubber (like surgical) glove, and zip-tie it over the open brake fluid reservior. Cut off the end of one of the fingers and blow it up like a ballon, then crack open the brake bleeder. It will force the air thru the system.

I have the CRJs. They are real nice billet pieces, strong as hell. They do make the shock stand up a bit straighter which shortens stroke somewhat, but it's not significant. Overall a good mod, they improve stability a lot.

They'll work. You will obvoiusly need to jet a lot bigger, and you will lose any semblance of bottom end power. It will hit like a sonovabitch on top and be WAY loud.

26 mm I believe.

If you are going to keep the stock cages, go with the Boysen reeds. They give a bit better throttle response, and will live longer than the stockers. The Rad valve is a waste of money, if you are going to buy aftermarket cages, do it right and go V-Force.

I have no clue what the bluetraxx guys are talking about. I can easily adjust my RS plate with a 10mm wrench.

I beat YFZs all day long on my (mostly) stocker. If you wanna build a drag bike, plan on putting together a BIG toolkit!

2nd hand info here, but I have heard that the 2 into 1 is the deal for trails, really help the bottom end. Top end is always gonna run stronger with dual carbs.

Lota guys using 80:1 or 100:1 in the good oils. The main thing the oil does is lube the bearings; rings will run a long time at even leaner oil mixtures. I think anyone running factory (crap bearings) shouldn't go thinner than 60:1 with good oil. I like Benol, but the castor oils do tend to leave exhuast deposits. I'll be running full synthetic at like 80:1 after the full rebuild.

2nd the Ourys, got em on every bike I own.

Ditch that shop immediately! They are either crooked or stupid, the CDI has nothing to do with the lights. I had this last year; went thru the harness, tracking back from the lites at each connector; never go any juice. Checked the lighting coil per Clymer's and that's what it ended up being. The Ricky's 200 watt was a real nice upgrade.

The only reason Iceman is busting your balls is that this comes up a lot. The nice thing about Noss is that you can change domes out easily and get big gains with high compression with 18 or 19cc domes on race gas, or run low compression (21cc) and get improved engine cooling.

Yup, I see your point, but this pic shows lots of heat around the rings, scuffing, and obviously the hole, but not the general pitting all over the piston face like we usually see with detonation. I think it's a textbook example of a lean but not detonating blown up piston. I was running this POS on crap gas, left over from the previous winter. Sled motors are real low compression so it takes a lot to make 'em ping; like an outboard boat motor.

Yes.. well, no. Depends on how close you are to a machinist who can do a decent milling job for a reasonable price. The best and nicest way to go is the Noss (or other aftermarket) head. They provide better cooling and give you the option of changing dome size. But my bike hauls butt and doesn't overheat, so I like the shaved head just fine.

I would guess around 170 to 190 Psi, although it should start ok with anything over about 120 in the cold. 100 psi is the lowest compression most 4 strokes will run at.

This one is out of my old Ski-Doo Mach 1. I guess that last pass of 110mph in the dunes was too much for it. This sled wasn't jetted for sea level so it was running very lean as well as very hot, since sand doesn't cool the exchangers nearly as well as snow. If this is what Cadillac's piston looked like, I would say it was lean rather than detonating.

Well, here's the wakeup call for him- You CAN'T run 92 octane in 18cc domes! The extended WOT running of Dumont didn't help either, since I still think he was running lean on that cylinder as well. Your buddy needs to do some homework, or he's just gonna keep burning up motor after motor.

Super lean! That hole is there because the plug was glowing white hot until it melted thru the piston.

Well Slimeball, the stator plate sits behind the flywheel. The pickups which determine when the spark fires are located on this plate as well as the stator windings that produce electrical power. By slightly rotating the plate, we can change when the spark occurs in the combustion cycle. Basically the only difference between an adjustable plate and a fixed plate are that the plate mounting holes are slotted in the adjustable style. You can modify your factory plate to accomplish the same thing, but you will need to use a small measuring stick to determine the amount of timing adjustment you are setting, while the aftermarket plates have the marks cast into them.

The 250F is one hell of a woods and track bike. I would do a compression test, and if that's OK and everything else looks decent, then I would buy it if it really is cheap. It's probably a carburetion issue if the compression is good; although a worn out spark plug and tight valves can definitely cause problems. I just fired up my XR650R in the garage tonite (going to the dunes tomorrow with it and the shee) and it fired up on the 3rd kick at 35 deg air temp.

Rooster, I figured out later that you were referring to the factory leaflet that comes with the bike, and you're right- it's worthless! Dunno about Haynes for the shee, never seen one. Seems like everyone uses Clymer's and for good reason; they go into pretty good detail. I wouldn't gamble on Haynes, go with the tried & true!

Aftermarket carbs WILL eliminate the TORS. As long as they come with tops and idle speed adjustment screw, which they should. And I do agree with Rooster on the head milling. Had mine done for like $50 and it made a world of difference. Combined with an adjustable stator plate, you will be able to get big gains with race gas and still be able to run super unleaded safely, albeit with smaller gain. It's money well spent.

I respectfully disagree. Clymer's does a great job of laying it out.

I live to serve.