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Discussion Starter #1
96 Formula III 600
New plugs and just filled up with gas

Problem:
I start it up and can run for about a 1/4 mile or a minute or 2 then the engine abruptly stops. It doesn't really sieze up because I can start it up again, but I did have to work the clutch back and forth a couple of times to be able to pull it over.

I originally thought maybe this was symptoms of it wanting to sieze up for good but what are your thoughts. I thought maybe it is just using up the gas in the bowls and just quiting when it's gone. It also backfires a bit when warming up but that may be unrelated. Is it possible I filled it up too much and the cap can't vent properly.

[red]Moved to the shop by Erick[/red]
 

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If it's abruptly stopping & you had to work the clutch to free it up again, I'd say it's definitely seizing.
Pull your plugs and see what they look like. Look for shavings of aluminum on them, and note what color they are. If they're white, it's running too lean - Not good. Brownish/reddish color - perfect. Black - running too rich.
I think you'll find they're going to be white.
If you've seized it a couple times, you're going to have to rebuild the top end, at the very least put a new set of rings in it.
 

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Discussion Starter #5
Well I pulled the RAVE valves off, (Found one without a spring!)and pulled the plugs. the 2 outside pistons look great but the center one is pretty rough. The RAVE valve, piston, and plug were all a little dirtier, more black and drier than the other 2. Not white piston wash or plug color though. Anyway, I think I am going to have to put a new piston in the center.

Couple of questions, could these have contributed to the failing of that piston?
1) The dealer had BR9ES plugs in instead of the service manual's recommendation of BR10ES which run a little cooler.
2) Will the missing RAVE spring contribute to the failing of that piston?
 

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the br9 wont realy do any harm xept in realy warm conditions...
hmmm...centr piston blown.not the usual, sticky rave will usualy run you rich...id like to know what that piston/cyl look like. no quick answer to give!
 

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rev the sled up to roughly 3000 rpm and kill the engine. listen on the clutch side for the crank bearings. if you can hear a spinning noise then your end bearings are finished. you see when the engine comes to a idle, the engine wants to stop abrutly because of these bearings catching up, but thesled will start right up again because you are forcing them to turn. this happened to me once and that was the problem. and yes your piston will look damaged.
 

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Also check your Oil Injection lines to make sure there are no air bubbles in them. And also make sure the oil pump is properly blead of all air. It sounds like you must have bought this sled used if there was a spring missing out of one of the valves, so who knows what else may have been done to it. If this seems to be ok, look for the restricted main jets or the like in the carbs. If you look at your piston you will know if its an oil or a lean condition by where the damage is on the piston. If the damage is above the wrist pin it is due to a lean condition. If the damage to the piston is below the wrist pin it is due to lack of lubrication.

Just some thoughts.
 

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Discussion Starter #9
Update time:

Had the sled in, and the verdict was that the center piston was partially fried (exhaust side) due to a "hot-cold" condition. Apparently when we were ditch riding from the trails the night before we would have to ride on the road for a while and we tried to jump into the snow whenever we could. When you do this, I guess the triples are prone to quick temp changes on the center cylinder and that little expanding/contracting can cause my partial melt down and partial seizures of that piston. So the sled was seizing once in a while due to the damage to the center piston.

Looks like I have a little summer project, anyone replace the center piston on a triple and can offer any advice or tricks?
 

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since it's a summer time project i would do the whole top end. unless u want more problems next season.good luck
 
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