Soupbox660 Posted January 17, 2006 Report Share Posted January 17, 2006 Ok, I don't mean to bug anyone with 4 stroke questions but since this is the best source I thought I would go ahead and ask. My friend and I rode all day on Sat. and Sun. When we got done, we decided to do a compression test on the Banshee. It came up to 115 psi in one cylinder and about 110 in the other. So not too bad. Then I decided to test the Raptor. Well, we looked up the specs and at 9.2.1 compression, its suppose to be 180 psi from the factory. Well I knew it wouldn't be that good, but 160 would've been okay. So we set it up and held the throttle open and turned it over. It read 90. Yeah 90. Now if that was really the case it shouldn't even run. And if it did it would be hard as hell to start, but its not. Plus it still runs good. Now we thought that maybe the threads were different for the compression tester, but it still seemed to fit okay. Some of its other symptoms are that when you first start it, it smokes terrible. It looks like WW3 coming out of the pipe. But then it goes away and doesn't burn anymore oil while you ride it (even after running it super hard). Its probably a valve guide clearance issue, but I'm not sure. Then there is the solution that always scares me: CRACKED HEAD!!! AHHH!!! But I don't think so. I was wondering if anyone has had any similar experiences with the Craptor or knows any other solutions to the compression reading and the oil burning problem. Thanks Everyone Quote Link to comment Share on other sites More sharing options...
aguita Posted January 17, 2006 Report Share Posted January 17, 2006 Smoke at startup is usually an indication that the rings are getting old, smoking while it runs means the rings are getting ready to be replaced. Smoke coming out of the bike when warming up in cold weather doesnt mean anything is wrong with the bike, necessarily. Stock is 182psi, I think 170 is the low end of the "ok" range. dont know about the compression tester but if ur in the 90Range you need a new top end ASAP! Also Smoke at start-up can also mean worn valve guides/seals. After the machine is run and then shut down, the oil seeps past the worn seals and into the combustion chamber where it is burned on next start-up. If it smokes on acceleration after it warms up....most likely worn rings. Quote Link to comment Share on other sites More sharing options...
no fear zac Posted January 17, 2006 Report Share Posted January 17, 2006 It might be because of the compression release. Quote Link to comment Share on other sites More sharing options...
Animalman294 Posted January 17, 2006 Report Share Posted January 17, 2006 The smoking during warm up is probably due to the motor not being warm yet. When it does warm up the metal expands making the rings fit tighter so the oil doesn't leak by as much, but it sounds like he is in line for an overhaul. Yes 90 is really really bad, and needs to be taken care of before severe damage occurs if it hasn't already. Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted January 17, 2006 Report Share Posted January 17, 2006 if its supposed to be at 180 i highly doubt it would start, let alone run at 90 psi. something else has to be fucked up... Quote Link to comment Share on other sites More sharing options...
suzuki0702 Posted January 18, 2006 Report Share Posted January 18, 2006 nice avatar loco..is that ur girl... try another tester..i think that the craptor's do have a compression release on em too..later Quote Link to comment Share on other sites More sharing options...
sandrappy Posted January 18, 2006 Report Share Posted January 18, 2006 First thing I would do is get another tester to use. If your banshee is reading 110, that is low for a banshee. With stock domes and stock pistons and no porting banshees should be around 130psi. Also, raptors do have compression releases. No stock raptor will read 180. I can't remember what mine was stock but I don't even think it was more then 150. From your description it sounds like it needs rebuilt regardless. Some times engines will smoke at start up because oil leaks past the valve seals while the engine is hot after it has been shut off. Then when started again it burns all of the oil that has leaked into the cylinder. Its hard to tell, there could be a hundred different things for why it is smoking on startup, but one thing is for sure if it is smoking blue it is burning oil and that's not good! Quote Link to comment Share on other sites More sharing options...
Soupbox660 Posted January 18, 2006 Author Report Share Posted January 18, 2006 Well, I already figured that the oil is leaking passed the guides while it sets. Yes, I know that the Banshee needs to be rebuilt too. LOL But I didn't know about the compression release. Thats huge. Thanx for the info. As far as my decision. I'm going to go ahead and rebuild it and I think while I'm in there I'm going to throw in a new Stage 1 Hot Cam and a Wiseco 666 11.1 kit. What do you guys think of that setup. I'm going to get a 450 next fall, but I figure I will do something to the Raptor for now. As far as the Banshee goes. Don't be sad. Its getting new carbs, a rebuild, and a Gorr Woods port. Thanks guys Quote Link to comment Share on other sites More sharing options...
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