http://www.x-h2o.com/index.php?threads/carburetor-specs-database-superjet-and-blaster-1.19403/.
Lots of setups in there
Lots of setups in there
B-pipe Carb jetting
- Thread starter flyHigh
- Start date
Why would you think its lean? I am planing to change the pistons this winter I will check for scorching during that time.
The amount of carbon on there with almost nonexistent wash.
Now you got me confused. I was under the impression you get a stronger carbon buildup with a rich mix or to much Oil (I was running 1:40). I guess I have to read up on that topic.
Pic from SnoWest snowmobile thread but same principal.
I’d also say center isn’t quite perfect, but should definitely have some clean piston showing on the piston side closest to the intake
- Location
- Los Gatos, CA
It is counter-intuitive but you will see the clean piston as it starts to get richer, which is called the piston wash. You can also eye it through the spark plug hole with a flashlight rather than remove the cylinder head. As it gets leaner it will be solid black like yours. You can just barely see the wash starting near one of the ports in the bottom left in your photo.
You want to see clean piston area near the ports on the sides of the cylinder. It's really hard to get a photo through the spark plug hole to show you.
I'm also no expert but I would want it a little richer which makes sense based on your jetting and the FP recommended jetting.
Where are you on the LS and HS screws?
You want to see clean piston area near the ports on the sides of the cylinder. It's really hard to get a photo through the spark plug hole to show you.
I'm also no expert but I would want it a little richer which makes sense based on your jetting and the FP recommended jetting.
Where are you on the LS and HS screws?
Thanks for the reply. I will check the LS and HS screws and will let you know later or tomorrow. As I am adding a head and enhancer I will re-jet the carbs anyways (135, 75, 115 springs). Will the piston-wash be visible after I have the correct fuel air mix if so how long will it take for the carbon buildup to clear out approximately? Is my assumption right that piston-wash is used for fine tuning since I could not feel any hesitation while accelerating at all? Also the whole tuning with a tach sounded good in theory but when I tried riding WTO while monitoring the tiny screen of my TinyTach to see if RPM's where dropping did not work out at all. But maybe that's just me.
- Location
- Los Gatos, CA
I have been pondering the same thing because I want to use a tach for the fine tuning. How does one look down at the tach and look for tiny changes while WFO on glass, trying to keep straight?
I have found when I make a small HS screw change, at the end of the day I can see a difference in the piston wash. So from my limited experience it should only take a few hours, but I don't know the minimum time.
I have found when I make a small HS screw change, at the end of the day I can see a difference in the piston wash. So from my limited experience it should only take a few hours, but I don't know the minimum time.
- Location
- Los Gatos, CA
Ok, I tried to take a photo of the PTO piston showing the piston wash thru the spark plug hole. If you look near the intake ports (basically all sides except exhaust) you see the clean section creeping in on top of the piston. In the photos you can see the boundary of the clean section and the carbon. It's hard to get a photo and easier to see by eye.
Also I find even with a 1/4 turn richer HS for the MAG carb as the service manual specifies, the MAG piston always has more wash (cleaner) than the PTO piston. So be sure you check both because the PTO could be too lean.
I'm not an expert but this looks fairly well jetted to me. As I look all the way around, it looks pretty close to the center image in post #25 above.
Also I find even with a 1/4 turn richer HS for the MAG carb as the service manual specifies, the MAG piston always has more wash (cleaner) than the PTO piston. So be sure you check both because the PTO could be too lean.
I'm not an expert but this looks fairly well jetted to me. As I look all the way around, it looks pretty close to the center image in post #25 above.
Tune the main circuit with a tach in smooth water. If your pilot/popoff is close to stock, you will lose throttle response before the main circuit is leaned to peak rpm. Adding larger pilot jet and/or lowering popoff will make it sputter a lot at 1/4-1/2 throttle but will allow good response with the main set at peak rpm. Skis are very easy to burn up so always start with carb settings that should be way too rich and lean from there. You may be surprised to find the best settings are much different than everyone elses. This is because very few riders actually go through the process.
- Location
- West Michigan
Hey guys, I just purchased a 2013 stock superjet and installed MSD enhancer and just received limited factory b pipe. Could some one please tell me what I should rejet my carbs to? I am 600' above sea level. thanks@
- Location
- West Michigan
Well I figured out the jets I need, but ran into an unexpected issue, I need to set the high and lows on my twin carbs, but I am not sure where they are. Only screws I see appear to be the ones in the middle of the carbs that keep them aligned other than the throttle stop. I have searched for pics on line, and no luck. Is their a high and low on each of the carbs?
- Location
- Los Gatos, CA
What year is your ski? They do have H and L screws but are likely covered by brass plugs that need to be removed. Post a photo?
If you look close there is H and L text cast into the sides of the carb.
- Location
- West Michigan
thanks I found the spot where they should be, where the "H" is, and it appears to be cast solid. I attempted to chisel with small screw driver, no luck, then used a razor blade and it seems to confirm this. Is their another way to adjust high and low on 2013 superjet dual carb?
- Location
- Los Gatos, CA
Yes they are adjustable, you need to remove the brass plugs first though. You may not be seeing them because it is all painted black.
It's the same as any early Mikuni SBN, you can also google a photo of those and see where they are.
Be careful when drilling in, I drilled into one of the L screws slightly. What I found worked best was to thread in a screw as shown but use a small slide hammer while pulling on it. I tried pulling with my hand and pliers and they didn't budge. With a small slide hammer they popped right out.
See the thread here for a few photos of what to modify: http://www.x-h2o.com/index.php?thre...s-for-mixture-screws-longer-t-handles.155863/