dajogejr Posted June 22, 2009 Report Share Posted June 22, 2009 If it were me...those were smacking the head pretty good. I'd be pulling the crank and checking it as well. Quote Link to comment Share on other sites More sharing options...
blowit Posted June 22, 2009 Report Share Posted June 22, 2009 If it were me...those were smacking the head pretty good. I'd be pulling the crank and checking it as well. :thumbsup: X2 Had to have knocked the crank out of phase. Good idea to check that thing out for sure... That ain't no .030" of squish. We have run motors as tight as .020 without any contact problems. The rod will NOT stretch that much so that just leaves bearings and pistons. Sloppy tolerances and fits will certainly cause this. I will admit, I have NEVER seen one that bad!! Can I have one of the pistons for educational purposes. :geek: B Quote Link to comment Share on other sites More sharing options...
Martinm210 Posted July 1, 2009 Author Report Share Posted July 1, 2009 FYI, Got my cylinders back from the shop bored out to 65.50mm. I split the case and checked out the crank and cleaned everything up really well. My new cylinder bore job came with weisco pro-lites again, and the same thinner metal gasket that I used before, so I did my first squish check with grease and solder pieces on all four corners with the single thin metal gasket. Of the 8 spots measured, they were all .018" to .020", so I guess I can confirm that 20 thousands ISN'T enough. I'm going to double up on the metal base gaskets which are .015 which should give me around .035" or so and check squish again. I'll report back later...just wanted to update you and say thanks for all the help! Quote Link to comment Share on other sites More sharing options...
okbeast Posted July 1, 2009 Report Share Posted July 1, 2009 Have your cylinders been decked before that you know of? No I would say .020 is not enough squish lol. For a stocker bike I'd shoot for somethin around .035-.045. This number varies from person to person but that's a safe range. Make sure to use some silicone if you're gonna double up on base gaskets too, i recommend the spray on copper gasket stuff, it's not messy to spray and just slide 'em on and works great. Quote Link to comment Share on other sites More sharing options...
Martinm210 Posted July 1, 2009 Author Report Share Posted July 1, 2009 Have your cylinders been decked before that you know of? No I would say .020 is not enough squish lol. For a stocker bike I'd shoot for somethin around .035-.045. This number varies from person to person but that's a safe range. Make sure to use some silicone if you're gonna double up on base gaskets too, i recommend the spray on copper gasket stuff, it's not messy to spray and just slide 'em on and works great. No, I don't know what was really done before. I bought the bike from a friend, but he bought it pretty much the way it is now with all the work done by the previous owner. The crank was brand new this time, maybe it was one that has a little build in length for extra compression, not sure. I sold off the old crank, so I don't have it to compare to anymore. The new boring is showing much much improved ring gap as well. I think the cylinders were worn enough that I had too much play. Ring gap before was probably .030 before, now it's about .012" with this fresh bore. I tried two gaskets last night and only came up with .030-.034" squish, so I'm still a little short. I didn't use any silicone/liquid type of gasket though, so maybe a good application of some liquid on all the layers will add up a few thousands worth. Regardless, it's odd that even with two of the thinner gaskets that I'm still so tight, there must have been something done to the cyliders, the head, or the crank itself. Something doesn't add up that I need so much base gasket thickness. Quote Link to comment Share on other sites More sharing options...
okbeast Posted July 1, 2009 Report Share Posted July 1, 2009 (edited) I always used the paper gaskets that cometic sold in their kit. I don't know how thick they were but I'm pretty sure it was more than .015". Are you using a stock head or a coolhead? Edited July 1, 2009 by okbeast Quote Link to comment Share on other sites More sharing options...
Snopczynski Posted July 1, 2009 Report Share Posted July 1, 2009 I recently bought this 94. It had a hole in one piston, so I went through the motor. Found what looked like a partially siezed water pump bearing, and backward base gasket covering up the failed piston side. I ended up replacing the waterpump and bearing, installed all new bottom end seals, new crank, and and bought new Weisco Pro-Lite pistons. I think the last pistons were standard weisco pistons. Anyhow, a weekend later it gave up and would only run on one cylinder. Took it apart and found one piston had partially broke, but closer inspection it appears both were having squish/impact problems. Not sure if it was the gasket, the pro-lites, or the crank that was ever so slightly different. The old melt down didn't appear to have any problem with squish, just melted a hole which I think was due to the waterpump and/or that base gasket covering up half a transfer port. So on my round 2 rebuild, I'm sending the cylinders in to get bored out. I think the old bore was a bit worn which may have been part of the problem. Anyhow, here are some pics...too little squish is apparent. So...how much is right? I'm definately checking this next rebuild. The banshee is a 94 with a Hotrods standard crank, cylinders have been ported (will be going up to 45.00mm), the head is a chozen performance head (not sure which domes, but supposed to be the max for pump gas), FMF fatty pipes, K&N filters, +4 Ign. Adv. The bike ran awesome when it ran, but I definately want to check and set the squish properly this time.. So my question is: How much squish should I have with this setup? Do you think the dome in the picture is still ok? Should I polish it or anything? The marks left are very shallow and don't appear to be enough to cause a problem. I've got the case split right now to clean out all the little bits of aluminum and the cylinders are already off to get bored and matched to some standard weisco pistons. I would set it at .045" with fatty pipes. If you go to a better mid-top pipe I would increase it a little more. Quote Link to comment Share on other sites More sharing options...
Darthwall Posted July 1, 2009 Report Share Posted July 1, 2009 you shouls post up a pic of the gaskets you are using a normall stock gasket is .020 thickness they also make .010 and .030 gaskets what it sounds like is the previous owner got the motor too hot and warped a cylinder then had the tops or bottoms decked down to make it flat again so if that is the case this makes alot of sence why you are having so many problems Quote Link to comment Share on other sites More sharing options...
toolman Posted July 2, 2009 Report Share Posted July 2, 2009 Not that it matters what compression did this motor have. Quote Link to comment Share on other sites More sharing options...
joee20002 Posted July 2, 2009 Report Share Posted July 2, 2009 check this link out cascade has some thick gaskets... http://67.199.65.66/cascade_innovations/ne...ore_dept_id=585 Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted July 2, 2009 Report Share Posted July 2, 2009 Are you using a stock head or a coolhead? he's using a cool head.....check out the pics. Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted July 2, 2009 Report Share Posted July 2, 2009 No, I don't know what was really done before. I bought the bike from a friend, but he bought it pretty much the way it is now with all the work done by the previous owner. The crank was brand new this time, maybe it was one that has a little build in length for extra compression, not sure. I sold off the old crank, so I don't have it to compare to anymore. The new boring is showing much much improved ring gap as well. I think the cylinders were worn enough that I had too much play. Ring gap before was probably .030 before, now it's about .012" with this fresh bore. I tried two gaskets last night and only came up with .030-.034" squish, so I'm still a little short. I didn't use any silicone/liquid type of gasket though, so maybe a good application of some liquid on all the layers will add up a few thousands worth. Regardless, it's odd that even with two of the thinner gaskets that I'm still so tight, there must have been something done to the cyliders, the head, or the crank itself. Something doesn't add up that I need so much base gasket thickness. adding silicone to the base gaskets, would hardly net ya .001". also, there for sure has been something done to the cylinders. i gave you measurements to compare yours too, so you could see what exactly was done to your cylinders. not sure why you didn't measure them up yet and post your measurements. measure up your cylinders and report back......the full cylinder height from base to deck and from deck to exhaust port roof. Quote Link to comment Share on other sites More sharing options...
Martinm210 Posted July 2, 2009 Author Report Share Posted July 2, 2009 (edited) The jugs appear to be 102.5mm, so it's not the jugs. I think it's the crank is a special order slightly longer crank. The problem didn't seem to be an issue with the stock crank, so that's got to be it...hard to measure though. I ended up having to go 3 gaskets thick and now have .045 to .047" squish. Like you guys said, the yamabond didn't add up to much of any thickness and with only two I was only at .032-.034" which was too tight for my liking. That extra thick base gasket would have been ideal, but I think these will be ok. They are the thin .015" metal reinforced types and I used yamabond in between the layers. Anyhow, I think it'll be good this time. I have .045" to .047" on squish now. Unfortunately I smashed an o-ring on my head, so I've got a new set of o-rings on order too. It should be here tomorrow then I'll be ready to put the bike back together. Thanks for all the help. My biggest error was rushing things and not measuring and checking. This time I measured and remeasured squish 5 times until I got it right. Ring gap is also measuring a nice tight .012" where previously I think it was well over .030" because the bore was so worn out. I didn't measure compression before, but I will this time. Edited July 2, 2009 by Martinm210 Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 2, 2009 Report Share Posted July 2, 2009 We've all broke some shit here and there learning, I know I sure as shit have. Usually, this serves as a learning purpose...and as many times as people say I just threw it together, there are cases it will come to bit you in the ass. Your squish is fine now...run it!! Quote Link to comment Share on other sites More sharing options...
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