ssanddemon

Running lean for sure; classic symptom.

The 2's have a problem with the screws backing out, without a doubt! I had the same problem with mine, finally threw them out and bought a new set. LATER I found out that Moto Tassini will warranty those 2's! Major bummer, I had pissed away $200. If nothing else, you can warranty them and sell 'em on ebay, then go buy a set of 3's.

I've got an old style PEP I got on ebay for $20. Works great! I'm sure it's a POS compared to the expensive ones, but it's SOOO much nicer than before.

Gotcha. I thought it was a runout issue. No big deal with a cup shape, just big pad wear.

To check for the leaking seal or base gaskets (or head gasket for that matter), you could do a leak test on the motor. If it's not holding vacuum, that will narrow things down a lot! Looking back, I should have done this- that seal was a BITCH!

Definitely replace the plugs. If that doesn't help- just about everthing will flip from side to side. Spark plug wires, reeds, carbs (plug the choke tube), and etc. Swap things one at a time and retest. I had the exact same problem, really stumped me for a while when the swapping didn't turn anything up. It ended up being the left side crank seal sucking air and screwing up the mixture at the lower rpms.

No to the spark arrestors. I ride Winchester all the time and haven't ever been checked for sound- they only do it on the big weekends like the 4th, Memorial and Labor day.

I get about 1 1/2 hrs on a tank, about half of what I got before mods. At Glamis, I am always the one who makes everyone come back for gas, the DSs and Raptors and 400EX need about 1 gal for my 3 1/2.

Running a warped rotor causes the caliper to shift back and forth on the pins as it follows the warp. 1/4" is a LOT! I would try hard to find a new rotor before the event. Failing this, make sure there is good lube on the caliper slide pins and flip the rotor as necessary to prevent damage.

Another reason why I don't trust Alba. Anyone who has installed V-Force will notice an increase in power, both on the top and bottom. I don't know why Alba skewed the dyno results to bash V-Force, but that result cannot be correct.

fast87, it wasn't a matter of seal installation technique. The problem with the Pro Flow was in the alignment of the intakes in relation to the boost bottle. The two intakes are seperate, only connected by the bottle between them. Since the difference between the spigots was less than the difference between the holes in the bottle, the grommets had excessive pressure on one side, eventually causing them to be 'cut through' by the spigots against the edges of the holes in the bottle- if that makes any sense. The design of the bottle-to intakes is such that it requires near perfect alignment due to the lack of flexibilty of the grommet sealing system.- Off by a couple of milimeters and it's leaking/ damaged. It's one of those things that I could have corrected by enlarging the intake-to-cylinder mounting holes, but it was easier to throw the damn bottle away rather than to deal with it and keep the bottle for cosmetic reasons. It was in the way of my fuel filter anyway.

Port job and new pistons (might as well since you're in there anyway), weld the crank and case match the cylinders. You'll probably need a beefier clutch to hold the power. Also, my bike really liked the 13 tooth front sprocket for Dumont and Glamis.

I have the Pro Design Pro Flow. It's a good-looking piece, but I found that the integral boost bottle leaks (sand into my motor!) at the grommet. Kept chasing vacuum leaks at those grommets and tried everthing short of silicone sealer (cuz it's ugly) to get it to seal. Replaced the grommets, but eventually the new ones would pinch and start leaking again. I ended up taking off the bottle and using the factory balance tube across the top spigots. Just thought I'd throw that out there, I woulda been pissed if the motor had gotten hurt over this design flaw.

I'm talking about the sand, I never ride in the dirt. I'm sure that dirt is a different situation in regard to racing. In the sand (hillclimbs), my piped 98 500 would easily beat stock banshees, but merely stay even with the piped ones unless there was room to get into the upper gears, where they would run out of power and my toque kept pulling hard. Technique was to give 1/2 throttle in 1st gear, a little more in 2nd, then fan thru the rest of them. This would carry the front end for the first 100 yards or so. The main problem in the sand is traction, and the pipier bikes lay down power a lot better than the torquey ones. The hard snap of horsepower 'locks up' the sand, where the slower delivery of four strokes and the big bores let the sand flow a bit, causing mushy traction. Quads have more than twice the tire surface area, and aren't trying to dig to china for the first hundred feet. So maybe this is what I meant when I said that the small bores run with the 500s. In the sand, power delivery affects traction in a big way.

Gee Loco, I'm sorry you were offended and felt the need to compare your machine to mine. A guy asked advice and I gave it. With a stock bore and stroke, my banshee is by no means the fastest, nor do I claim this. By the way, I have a CB 650 motor in my 87 LT250. I felt that the 650 was a worthwhile swap due to the poor quality of the original powerplant- as opposed to the superior 350 twin that Bill already has and might repair for little money and few hassles.

I ran a piped 98 CR500 for a couple of years. I think the main reason they discontinued the bike is that they weren't much faster than the PV'd 250s. I run a YZ 250 now and it would pretty much have run with my CR500 (and is WAY faster than my old YZ 490). The 500 with porting would be a whole 'nother story- If it was set with a good woods type port, it would retain some bottom and actually flow on top. Something to keep in mind anytime a CR500 swap is considered is the massive vibration of these motors. I can't remember the fix, but I heard a lot about in in the days when the 250R was king and everyone was doing this swap.

I think break-in is overrated. Lots of guys do it and lots don't, but I know of a lot of bikes that were thrashed from day one and still running great years later on OEM topends. Same with my other addiction, jetboats. We baby a new motor for a couple of minutes, then run her like you stole her: 5 to 7 grand ever onward. No big problems or guys wouldn't still be doing it this way. Just my .02....

Jeez BIGBILL, my ears are ringing! If things are really fried and you have more bad parts than good, you should think about a used banshee motor on ebay. The 350 twin is a really strong motor, it beats the crap out of everything else out there in term of power and reliability, plus your bike will be correct and not a worthless "morphodite" when you are done.

60, I had a similar problem earlier this year. I hadn't run the bike in a few months, ended up with little or no combustion on the left side until like 5 or 6k rpm. Swappered everything side to side (including carbs) and nothing helped. Tore the top end down, couldn't find a thing wrong. As a last resort, I replaced the crank seal behind the flywheel and that was it. I had put it in backward when I had the crank out for welding a couple of years before. It sealed up OK until I finally put the bike away for a while, then it must have dried out and started leaking air. As for diagnostic advice, this problem would show up on a cylinder leak test. I just didn't have the gear to test it, too lazy to take to a bike shop for it. The seal is a pain to repace though; might be work getting the leak test done prior to tearing into it.

... Or more likely replace the needle and seat.

Here's an idea since you're gonna scrap the flywheel anyway: drill & tap two holes in the face of the flywheel and use a harmonic balancer puller from the auto parts store. And this time, when you heat up the flywheel, be agressive with that hot wrench- REALLY heat it. It will expand on the crank and come off with not a huge amount of pressure.

Oops, dip$-it that I am, I did'nt see the pg.2 responses, sorry! Sounds more and more like a bad radiator cap: doesn't overheat much but spits coolant=bad cap.

If the radiator cap is f'ed up it will make the bike o-heat and spit coolant as well. Most auto repair shops will have a radiator cap tester with a small cap adapter to see if your cap holds the required 10 lbs. or so of pressure- it's a common size cap on the import cars. A sheared water pump gear could also likely do this type of thing as previously stated.

Seems to me that factory (max) output is in the 75 watt range. You are probably pushing the limits with the 85W you are pulling now and will only succeed in frying the lighting coil if you step it up even more. Give it a try I guess, but it would be a better idea to step up to a 200W coil, then run your two 50s (and more) with no problems. I used to run without the taillight until I got busted at night one time. Lucky I had the taillight in the box-o-parts or I would have been done night riding on that trip.

Something's loose in the back end, obviously. Your best bet is to have a buddy lift up and set the rear end down repeatedly while you have your head down there to see where the excessive play is coming from. It could just as easily be from the suspension linkage or the shock eyes. Changing out the bearings and bushings anywhere on the rear end is pretty straightforward. As always, a Clymer's manual will guide you with decent instructions.