LiftdT4R Posted November 13, 2006 Report Posted November 13, 2006 (edited) Ok, I had a +4 advance on my 2001 and I liked it, but I ride a lot of tight trails so I decided to try a +7 advance on my 2002 that I'm putting back together. I run Super now, it's like 93 or 94 octane. My 01 ran fine with a +4 advance, but I was wondering should I be expecting to use a higher octane now? I have FMF SSTs, with 280 mains, airbox with lid, and a lightened flywheel, compression is at like 125 each cylinder. I also want to eventually have my head milled too, should I use a higher octane then. I really want to stay on pup gas with this bike because it is mostly for trails and the pump gas is the most readily availible. Any info would be appreciate it, and I will listen for the pinging whenever I get it re-assembled as well. Thanks, Edited November 13, 2006 by LiftdT4R Quote
dajogejr Posted November 13, 2006 Report Posted November 13, 2006 You should be ok with +7 now and stock head. LISTEN to your motor though. However, I think once you get your head milled, depending on how much you go...you should back it off to +4... There are no gaurentees, only averages. If I had to guess, I'd say .020 off the head and +4 will be safe for premium pump gas, but...make sure your jetting is spot on, and listen to your motor, check your plugs freequently, etc. No way anyone can tell you with 100% certainty if it'll be safe.... Quote
LiftdT4R Posted November 13, 2006 Author Report Posted November 13, 2006 No way anyone can tell you with 100% certainty if it'll be safe.... Yeah, that's what I've heard, I'll listen for the pinging when I put it back together. The jetting is on spot, a little rich for the winter, I even bought the synch tool from Jeff, so both carbs match now. I got a degree key really cheap, so I stuck that in there, my other shee has the timing plate though. I probably won't do a milled head on my 02, btu the 01 will definately get it when it goes back together. Quote
Animalman294 Posted November 13, 2006 Report Posted November 13, 2006 Nicely put............... He's right just check your jetting often because it doesn't take long for a motor to go south........ :beer: Quote
dajogejr Posted November 13, 2006 Report Posted November 13, 2006 on my 02, btu the 01 will definately get it when it goes back together. Lucky bastard....two of them. One blows....ride the other. And they're both newer than my 96 dinosaur.. Although, there's not much left on mine from 96, more like 2006...so, what year does that make it?? :yelrotflmao: :beer: Quote
b33rs Posted November 13, 2006 Report Posted November 13, 2006 (edited) How much of a compression gain going from +4 to +7 do you think? just wondering btw :beer: Edited November 13, 2006 by b33rs Quote
LiftdT4R Posted November 13, 2006 Author Report Posted November 13, 2006 Lucky bastard....two of them. One blows....ride the other. And they're both newer than my 96 dinosaur.. Although, there's not much left on mine from 96, more like 2006...so, what year does that make it?? I only have 2 because I got the 02 insanely cheap, and after I finish my 01 project I'll be selling or parting it to re-gain some of my lost cash. Besides, that 96 looks nicer then both of mine, if I was gonna be doing dunes, I'd get the same setup, cubs are a little tough to trail ride though. :biggrin: I'm not sure on the compression gain, but I was looking for a little more low end hit. I went down 1 tooth on the front sprocket, and had +4 timing, but I still want a little more lowend. I know it's no 4 stroke, but a little more tump pullin power would be nice. Quote
dajogejr Posted November 13, 2006 Report Posted November 13, 2006 How much of a compression gain going from +4 to +7 do you think? just wondering btw :beer: Probably a few ponies, but it will be seat of the pants noticeable, and pickup some of the lost bottom to mid range. Quote
NYUK Posted November 13, 2006 Report Posted November 13, 2006 i would go 1 degree at a time. 4 to 7 is a big jump in heat. for nj trails 7 seems a bit much.go slow, better to ease up to it checking plugs. than a hole in your piston. Quote
r/atvshee Posted November 15, 2006 Report Posted November 15, 2006 i know im probably gonna bashed at for saying this. put i have +7 timing and a shaved head on pump gas. My motor has been running like its still new for about 6 months and over 100 passes on hills/drags Quote
dajogejr Posted November 15, 2006 Report Posted November 15, 2006 i know im probably gonna bashed at for saying this. put i have +7 timing and a shaved head on pump gas. My motor has been running like its still new for about 6 months and over 100 passes on hills/drags Nope...no need to bash! Every bike is different....period. You've obviously tuned yours carefully to get the results and longevity you've had. They break @ WOT more than idle...so, you're doing something right. But, we can all agree to start out safe and go in small increments. Quote
okbeast Posted November 15, 2006 Report Posted November 15, 2006 What will your plugs look like if you go "too high" on timing? I didn't know you could do a plug check to see if your timing AND compression are good. Quote
dajogejr Posted November 15, 2006 Report Posted November 15, 2006 You can't, really. If you have too much compression and/or timing, by the time the plug looks like a silver coated sparkler, it's too late. You have to listen to your engine. Quote
LiftdT4R Posted November 15, 2006 Author Report Posted November 15, 2006 i would go 1 degree at a time. 4 to 7 is a big jump in heat. for nj trails 7 seems a bit much.go slow, better to ease up to it checking plugs. than a hole in your piston. :woot: Actually this bike was run at 0 degrees for as long as I know of. My other bike has a 4 degree advance. I might just pull that key and throw in a +4 to be on the safe side, I don;t know, thought going to +7 might be nice but might not be worth it after all. If it aint broke don't fix it right? Quote
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