jstaguy24 Posted December 23, 2003 Report Posted December 23, 2003 If I start running a mix of racegas will I have to make any jetting changes and what will I notice different in the way they bike runs? Any help would be great I want to make sure all my jetting is done before spring Quote
Cotton eyed Joe Posted December 23, 2003 Report Posted December 23, 2003 If I start running a mix of racegas will I have to make any jetting changes and what will I notice different in the way they bike runs? Any help would be great I want to make sure all my jetting is done before spring The time I ran race gas and pump gas for a weekend, I noticed nothing on the plugs, or in performance really. I wasn't set up to use race gas anyway, but I wanted to see if it would in fact make a difference with my application. I don't think you would need to change your jetting unless you change the domes in your head (If you have an interchangable head design) or if you do some engine work like porting, or change to a different air filter, etc. Quote
jstaguy24 Posted December 23, 2003 Author Report Posted December 23, 2003 thanks cotton eyed joe. I dont have a banshee so I cant change my domes. The head has been milled and the engine was ported and things before I bought the bike. It has around 160 psi of compression. thats about as high as we could get it to go but you cant kick over that 500 motor for very long. when I bought the bike it was way lean on jetting and I siezed the motor. After the rebuild I rejetted and everything has been good since. But just to be safe I thought about race gas if its going to keep things cooler and running better. Quote
Blue Duece Posted December 23, 2003 Report Posted December 23, 2003 The time I ran race gas and pump gas for a weekend...... Jesus Stan was it race gas or pump gas?........ Quote
Wallrat Posted December 23, 2003 Report Posted December 23, 2003 You want to use the lowest octane gas that you can without having detonation problems. At that compression you're right on the edge of pump gas. You could mix race/pump gas for a little added insurance but don't expect any kind of performance increase. Higher octane fuels resist combustion longer but provide no power benefit. As far as jetting goes, just do a plug chop to see how its running. You won't have to alter the jetting by switching octanes. Quote
mcaf29 Posted December 23, 2003 Report Posted December 23, 2003 Yes, generally you will need to rejet. Meaning if you were already almost too lean then your bike will run fine with the race gas but if your jetted to the rich side you'll need to lean your jets out a size or two. For instance I was running 280's on full race gas, 300's on 50/50 mix and 310's on pump. Quote
boonman Posted December 23, 2003 Report Posted December 23, 2003 That's interesting Mcaf. I have never heard of such things like that. What kind of fuel was it? Was it oxygenated? Of course, if it was oxygenated, you would have to richen it up. I don't understand why the jetting changes. I switch between 50/50 and full high octane, and my jetting hasn't ever changed.... Quote
mcaf29 Posted December 23, 2003 Report Posted December 23, 2003 No clue why, but even my LRD's came with jet specs for race gas. I called and bitched that the jets they sent me were too small and they said they were for race gas, and I needed larger ones for pump. Sure enough I pulled out the install guide and it said jetting specs were for race fuel right on the sheet. It probably has to do with the cooler burn though (speculation). I was running C-12 BTW. Quote
Wallrat Posted December 24, 2003 Report Posted December 24, 2003 I read up on this and the basic conclusion is that you should try leaving the jetting the way it is first. You might have to change the jetting by switching octanes though. Quote
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.