stubz616 Posted February 28, 2013 Report Share Posted February 28, 2013 Hey Everybody, New tio the site and like what i've seen so far. Just put a Noss head with 20cc domes on my banshee, and it is popping from mid to top. runs great down low. Before the head it had right around 120psi on both cylinders, after it is right at 160psi. I'm at sea level at that pressure, and was wondering if there is any way I can run Pump Gas still (93 octane) with that compression or is that what my problem is? I have an adjustable timing plate that ranges from 10* retarded to 10* advanced. I was wondering if I could add some timing and maybe get it to stop popping, or am I going to have to run a mix of race fuel and pump gas. Thnaks in advance for the help Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted February 28, 2013 Report Share Posted February 28, 2013 That amount of compression is a bit past the capability of premium pump gas. The popping is probably dedonation related and you definitely need to up the octane, especially of you are also running any amount of timing. Try some 50/50 race/pump fuel or if you aren't in to the race fuel, try some new domes 2cc's larger. Quote Link to comment Share on other sites More sharing options...
notsed Posted February 28, 2013 Report Share Posted February 28, 2013 That amount of compression is a bit past the capability of premium pump gas. The popping is probably dedonation related and you definitely need to up the octane, especially of you are also running any amount of timing. Try some 50/50 race/pump fuel or if you aren't in to the race fuel, try some new domes 2cc's larger. x2 id put some 22's in and +4 timing, 21's might be ok depending on your timing... on pump fuel Quote Link to comment Share on other sites More sharing options...
stubz616 Posted March 1, 2013 Author Report Share Posted March 1, 2013 I know the timing is a little high, but I tested my friends banshee that he just bought with a noss head as well and he didn't know what domes were in it, and his came up 165psi. His runs great though on the same fuel. Thats what is baffling me. Is there any way I can re Jet the bike to try to cure it, or what should I do with my timing? Its been so long since I've been in the carbs I dont remember what the mains or pilots are, I do Know that the clips on the needles are in the bottom notch. Was really hoping not to have to change the domes, but if it comes down to it, thats what ill have to do. Thanks for the input guys Quote Link to comment Share on other sites More sharing options...
stubz616 Posted March 1, 2013 Author Report Share Posted March 1, 2013 I meant to type I know the "Compression" not timing... Srry Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 1, 2013 Report Share Posted March 1, 2013 Well, always make sure that any motor is jetted right. However, you can't jet away detonation from being under octaned. You need better fuel or different domes Quote Link to comment Share on other sites More sharing options...
stubz616 Posted March 1, 2013 Author Report Share Posted March 1, 2013 Would timing help out at all and if so which way should I go? Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted March 1, 2013 Report Share Posted March 1, 2013 Remember this.......EVEN if you built 2 identical motors.......they are still different. No matter what you cannot build 2 motors that will not have slight differences. You'll notice it too sometimes......exact same setups to the "T" and yet one likes running rich on the mains and one doesn't. So you can't compare your buddies to yours. Not to mention there may be other things that are playing factors.....different squish angels, different squish tolerances......hell....even the condition the domes are in can contribute. Adding timing WILL NOT HELP the detonation.......sometimes you can Band-Aid fix a very slight deto problem by retarding the timing.....but I must say.....its not a FIX......its a band aid. Just either change the domes, or run higher octane fuel. Hell I run 156psi and im running fine with no deto on pump fuels. Just remember.....it may cost you $65-80 for domes....but its gonna cost you $300 to rebuild your top end and $400 for a new crank when you let the deto keep trying to throw little fixes at your motor. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 1, 2013 Report Share Posted March 1, 2013 X2 Quote Link to comment Share on other sites More sharing options...
stubz616 Posted March 1, 2013 Author Report Share Posted March 1, 2013 I think I'm just gunna run it this year with a 50/50 mix of 93 / 110 and I'll swap out the domes next year to some 21cc domes. If this motor ever blows up its gunna get expensive because it will be getting some cubs then. Thanks for the help guys. Quote Link to comment Share on other sites More sharing options...
stubz616 Posted March 7, 2013 Author Report Share Posted March 7, 2013 Just an update, Tried running a 50/50 mix of 110/93 and my bike kept popping and cutting out up top just like before. Ended up putting in some 340 jets I had laying around and dropping the clip on the needles to the bottom groove (6th), and the timing is at +5*. Runs awesome now and the plug chop I did after looked great. I think all along it was running out of fuel, because i did a plug chop previous to the 340s and they were burning white WOT in 6th. But were burning a nice tan with the old head. Glad I finally got it figured out. hopefully my findings will help someone else out down the road. Thanks again for the help guys. Quote Link to comment Share on other sites More sharing options...
possum Posted March 7, 2013 Report Share Posted March 7, 2013 moral of the story. start rich and come down. will never fail you. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted March 8, 2013 Report Share Posted March 8, 2013 moral of the story......if you had done a plug chop and you knew it was burning the plugs white........why the fuck wouldn't you give us that info? haha.....shit if you said that we could have told you the problem within seconds of seeing your description. We cannot give decent info/ideas on what the problems can be if you hold back info from us..... 1 Quote Link to comment Share on other sites More sharing options...
stubz616 Posted March 13, 2013 Author Report Share Posted March 13, 2013 never had a chance to do a plug chop with the new head before then, was just throwing the problem out there to see if anyone else had experienced it, o well, you live and learn. thanks again Quote Link to comment Share on other sites More sharing options...
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