shogs Posted December 28, 2009 Report Share Posted December 28, 2009 My mods are as follows -Aggressive trail port -ptr mids -boyesen low-mid reeds - +4 timing -billet impellar -pro design cool head (currently running 22's) -single 35mm (if I remember correctly 190 or 195 main 45 pilot and cel middle clip) May have forgotten something but I think thats it for the engine. I'm 200-400 feet above sea level and was wondering if it was safe for me to run pump gas with some new 20cc domes I bought. And If it is what octane I need to run. I also needed to know if I need to change my jetting at all to compensate for the different compression. I'm assuming no but I wanted to be sure before I put them on. Yesterday I accidentally stripped my drain plug threads out pretty bad, and need a quick fix to get my bike up and running again. I heard I can just get a bigger plug and if its only a tad bigger just thread it right in, what do you guys think works best for fixing this problem? Thanks Quote Link to comment Share on other sites More sharing options...
Karac Posted December 28, 2009 Report Share Posted December 28, 2009 You should be able to get away with the 20cc domes with a 50/50 mix. 50% 93+ and 50% cam2 or vp. Quote Link to comment Share on other sites More sharing options...
DallasGDub Posted December 28, 2009 Report Share Posted December 28, 2009 Thats border line. What's your compression? You should be able to run 93oct @ the pump. I was pretty close to the same mods and @ 500', I was sitting at 155psi. 93 worked for me with no problems. Quote Link to comment Share on other sites More sharing options...
AtvFoxBoy86 Posted December 28, 2009 Report Share Posted December 28, 2009 (edited) Do you know what your compression is at? i would think at 200-300 above sea level it should put you at about 140-150, if your head is not shaved and you already had good compression. Edited December 28, 2009 by AtvFoxBoy86 Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted December 28, 2009 Report Share Posted December 28, 2009 It all depends on your port heights/widths,155 is max psi on pump gas that I would go,put them in and take a reading Quote Link to comment Share on other sites More sharing options...
AKheathen Posted December 29, 2009 Report Share Posted December 29, 2009 20's and +4 timing are fine on 93 Quote Link to comment Share on other sites More sharing options...
GNR101 Posted December 29, 2009 Report Share Posted December 29, 2009 20's you should be fine on pump gas.. i got away with 19's on pump gas.. but i was borderline Quote Link to comment Share on other sites More sharing options...
AKheathen Posted December 29, 2009 Report Share Posted December 29, 2009 20's you should be fine on pump gas.. i got away with 19's on pump gas.. but i was borderline yah, you have to be a bit critical with 19's even with a conservative .050 squish, but still possible........i ran 20's on 90 for a while with stock porting and timing Quote Link to comment Share on other sites More sharing options...
shogs Posted December 29, 2009 Author Report Share Posted December 29, 2009 Alright thanks guys. I wanted to be pretty sure I could run them before I put them in and had to do a comp check. I'm ready to run just gotta go to my local shop and get some gear oil and coolant and i'll be ready to run. I was wondering what you guys would do about the drain plug. I have high temp silicone and loctite handy. Would loctite be enough if I snugged the bolt up with plenty of it on there? Its not really stripped thread wise it just won't get extremely tight. I figured if that didn't work I could get a bigger bolt, but finding a bolt thats just a tad bigger than that would be pretty tough. Quote Link to comment Share on other sites More sharing options...
alf44 Posted December 29, 2009 Report Share Posted December 29, 2009 you will be fine with 20's. I ran them on that similar setup. If you a little leary mix it half and half with some 110. I wouldnt sweat it. Quote Link to comment Share on other sites More sharing options...
FrankieSquid Posted December 29, 2009 Report Share Posted December 29, 2009 You should be fine running the 20cc domes, I have seen people run on 19cc domes on pump gas similar to the mods you have. 20cc should be no issue Quote Link to comment Share on other sites More sharing options...
No Limit Powersports Posted December 31, 2009 Report Share Posted December 31, 2009 To just say one is fine with x cc domes and thats it, is totally incorrect. You absolutely have to factor in all of the parts that make up a given compression ratio, which is different than pumping pressure. A 20 cc dome is not close to the same ratio on a 64 bore vs say a 78 bore. Bore size, port heights, transfer volume, crankcase volume, elevation, pipe design, squish, spark plug depth -- in relation to dome size can make a difference on compression ratio. Now with that said a totally stock bike running 20cc domes on pump gase at sea level would be marginal with 0 added timing, and unless the tuner was fairly good I probably would not set up a bike that tight for pump gas. Pump gas is just to inconsistent to be reliable. Quote Link to comment Share on other sites More sharing options...
alf44 Posted December 31, 2009 Report Share Posted December 31, 2009 Its not a stock bike though. The only diff. in that and mine where I had t5s, vf-3 and a dune port and rode with 20cc domes for 2 years with no problems. Hes on stock jugs NOT 78mm. If anything wouldnt you recommend he uses a 21cc too be safe instead of scarying him into thinking were all stupid and dont know what were talking bout and hes going too blow up his bike? Just my opinion. 1 Quote Link to comment Share on other sites More sharing options...
shogs Posted December 31, 2009 Author Report Share Posted December 31, 2009 I put the domes in and I was glad to see my pistons were still clean and had no scratches on them. I installed the domes, clutch kit, clutch disengagement adjuster, and impellar I got from alf. The bike will roll as soon as you pull in the clutch and before you had to kinda push it. The clutch is a little harder to pull with the 3 heavy duty springs but I think i'll get used to it. The bike seems to scream and I almost pulled a 4th gear wheelie in grass with pretty old tires. I think I'm running it a little lean on the main but other than that its running great. The spark plugs were a pain in the ass to get in but is that because the domes were new? On a side note alf really hooked me up with my parts. I got about 9 parts that cost me right around $300 shipped. It would have been a pain in the ass to order from 2-3 different places but alf got me all I needed and one shipping/paypal fee. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted January 1, 2010 Report Share Posted January 1, 2010 umm, all that was covered with room for variance...... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.