CombatTalon2 Posted April 26, 2008 Report Share Posted April 26, 2008 Well, last trip of the year to the dunes and the shee was running great! Whooped a 350LRD Honda 250R that dynoed at 72HP running on VP112. Anyway, we did about 20 passes on the flats. On the last run the shee died on me in 6th pinned. Didn't lock up, just quit running. Started right back up and thought i had just run out of gas. Anyway, got back to camp (few hundred feet) and pulled the plug.....this is what i found. So i was pretty much done for the weekend with the shee anyway, Still had my CRF450 to ride. Get home and put her away. This morning i decided to see what was going on. So i tore her down. very burned crown, lookin pretty ugly. Left side, looks fine. Piston looks perfect, no scoring, no nothing. Right side, has some minor scoring on the piston, and cyl wall. Domes look fine, nothing wrong with them. So what do you think happend? Is it Detonation? Why on only one cylinder? My compression was around 125 at 3,000feet ASL. I think my compression numbers are low because of the port work. Fresh top end with 19cc blaster domes with a .060 squish. I looked at all my carb boots. Tugged on them while spraying with carb cleaner to see if i had a leak there. Nothing, no change in RPM at all. Plugs up untill this trip were perfect. Little bit fat on the mains (380s) and she had a tiny bog on the needle, checked with the choke pulled and it got worse, so im pretty sure i was safe on the needle. You can tell by the other plug that it wasnt running lean. This was about the 4th trip on this rebuild. all seals got changed last rebuild. Im possibly thinking that im sucking some gear oil into the crank case possibly (lookin at the black shit on the burned up plug) So, whats goin on? I have the thing tore down anyway, gonna split the cases, and see if there are any tell tale signs of a breech between the trans and crank case. Quote Link to comment Share on other sites More sharing options...
Frogger Posted April 26, 2008 Report Share Posted April 26, 2008 Sorry to hear about the mishaps. Any picts of the races though? Quote Link to comment Share on other sites More sharing options...
LS1Inferno Posted April 26, 2008 Report Share Posted April 26, 2008 Looks like shee was just a little warm, maybe a small piece of sand in the main, leaned it out a litte, Unliess teh problem is obvious who really knows with these things. Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted April 26, 2008 Report Share Posted April 26, 2008 Could have sucked a carb dry depending on how long you were at WOT? Quote Link to comment Share on other sites More sharing options...
CombatTalon2 Posted April 26, 2008 Author Report Share Posted April 26, 2008 Looks like shee was just a little warm, maybe a small piece of sand in the main, leaned it out a litte, Unliess teh problem is obvious who really knows with these things. yeah, looked at the carbs, 380 mains have a huge hole, i dont think a piece of sand would stop anything with those. I got the cases seperated. There was some oil in the right side crank case, but im not entirely sure if it was in there to start with, or after i flipped the engine over to take the lower case nuts off. I hate not knowing where the leak is at. I guess when i put it back together i will make a leakdown tester for myself, and make sure everything is good before i run it. Also found that the circlip for the idler gear had broken/fallen off and got eaten by the trans.....guess they are not lying when they tell you to replace, not reuse them Quote Link to comment Share on other sites More sharing options...
CombatTalon2 Posted April 26, 2008 Author Report Share Posted April 26, 2008 Could have sucked a carb dry depending on how long you were at WOT? yeah, im still thinking that might have been the case since it died at WOT in 6th. We were racing probably 1/8mile or so, long enough to be running in 6th for a few seconds. we were running back to back, so it might have been that we reset a little quicker that time, and the bowls were not completely filled back up? All i know is that for the 20 or so runs i took that 350PV 250R every time. Launched harder off the line, and held him the entire run. Quote Link to comment Share on other sites More sharing options...
Bansh-eman Posted April 26, 2008 Report Share Posted April 26, 2008 380's??? wtf where u riding that you needed 380's? Quote Link to comment Share on other sites More sharing options...
CombatTalon2 Posted April 26, 2008 Author Report Share Posted April 26, 2008 380's??? wtf where u riding that you needed 380's? Did a few plug chops after the rebuild. Didn't feel comfortable with anything less than the 380s. was running 360s before the last rebuild, but was also running banshee domes with blaster pistons, so they were like a 24cc dome with the wrong squish pattern. Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted April 27, 2008 Report Share Posted April 27, 2008 I put a Pignel on my banshee just insurance. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 27, 2008 Report Share Posted April 27, 2008 Could have sucked a carb dry depending on how long you were at WOT? Kinda what I'm thinking too...and the right cylinder will run out of fuel first, further road to travel for fuel. Too much carbon on top the other, you were definitely fat.... Quote Link to comment Share on other sites More sharing options...
CombatTalon2 Posted April 27, 2008 Author Report Share Posted April 27, 2008 Kinda what I'm thinking too...and the right cylinder will run out of fuel first, further road to travel for fuel.Too much carbon on top the other, you were definitely fat.... Oh, yeah i know it was fat. But i don't re jet from running in glamis at 50 degrees, to running at 90 degrees. I also run it in Tucson at 3,000 feet with the same jetting. All i know is it runs good, so i wasn't going to start leaning it out. Quote Link to comment Share on other sites More sharing options...
CombatTalon2 Posted April 27, 2008 Author Report Share Posted April 27, 2008 Kinda what I'm thinking too...and the right cylinder will run out of fuel first, further road to travel for fuel.Too much carbon on top the other, you were definitely fat.... I also run an inline fuel filter. I read some post a while back saying they restrict the flow just enough to allow the bowls to run dry. Quote Link to comment Share on other sites More sharing options...
ClimbAnyHill Posted April 27, 2008 Report Share Posted April 27, 2008 Could of been an air leak too. Looks way rich too! Congrats on the races though! :thumbsup: Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 27, 2008 Report Share Posted April 27, 2008 Unless you have a history of getting bad gas from your local stations, take the inline filter off. You have two screens in your tank. I would take the fuel valve out of the tank and check those for dirt/debris as well. Quote Link to comment Share on other sites More sharing options...
inthemail Posted April 27, 2008 Report Share Posted April 27, 2008 everything looks minorly unhappy inside, from being a bit rich to being "heat polished" (the domes) im with the other guys who are saying it ran out of fuel, one side of your delivery hose has a longer path. stupid eh? Quote Link to comment Share on other sites More sharing options...
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