Does the following pic look like a lean condition, or a detonation condition. Both carbs were set the same and the one on the right appears lean. My setup is a 62t 5mm stroker 83mm Yamaha waveblaster with b-pipe, 190 psi, and 20 Degrees with msd enhancer. It was running okay until I dried the pipe out a bit and then leaned out. My question is if I am too close to the limit to run 93 octane with 190 psi and 20 deg advance, or if I was just to lean and should go up a size.
Piston Wash question
- Thread starter coldblaster
- Start date
SUPERTUNE
Race Gas Rules
- Location
- Clearwater Fl.
Yes, You could be too lean, too much compression, bad head/squish chamber design, headpipe outlet too small, (650 size/needs to be at least 701 size) too big of a prop... Looks like you killed it now...pull it apart because you need at least the front piston, mic the rear piston and see if is bad too...IMO start over with a new bore and pistons, then go back to what you had setup before or go through everything else that's modified on the ski.
What do you mean by headpipe outlet? Between the Cyl port and the pipe or between the first and the second pipe. I'm just looking online now to find someone who has 83mm pistons in stock to order them. The Bore seems good no real marks and it has next to no time on it since it was bored.
SUPERTUNE
Race Gas Rules
- Location
- Clearwater Fl.
Measure at the 3 bolt gasket, 42mm is a 650 and 46.5-47mm is 701.
- Location
- Reno,NV
why is it advanced with MSD enhancer ? Is that what one should do or just a choice ?
masterblaster
X-H2
20 deg with a msd enhanser is retarded isnt it? It shows stock to be 22 deg at 2000 rpms.thats just a little above idle where static timing is tested right? with that little advance and 190 comp on 193 oct you would seem to have been alright.how long was this setup running before you dried the pipe out ?
The headpipe diameter is 47 or 48mm will double check today. The timing I thought was 20 deg I will check it tonight, I found someone with a piston so should have it running. The setup was only running for 10 to 20 min while I was checking the plugs and it was only reving out to 6650 until I dried out the pipe to make it almost sizzle water. Top screw is open 1/4 turn and other 2 screws closed. I have a .125 restricter into the stinger and am waiting for a jetworks valve to arrive.
masterblaster
X-H2
The combo of the restrictor and drying it out,would prolly have called for the next size up main jet,or at least a adjustment of the high speed screw.how many more rpms did ya get after drying it out?
The rpms were around 7000. The restrictor was in the whole time, just dried out the pipe but didn't richen the screws enough, I guess...