MicroSquirt.com read only forum (Jan.15,2018)

I have a 2001 seadoo RXX with a 951CC 2 stroke that has been bored out to 1020 CC. The problem I am having is it is leaning out from not enough fuel. Would like to keep my ignition as stock and set up the MS for fuel delivery only. Any ideas or thoughts would be apprecaited

This shouldn't be too difficult, though I would probably use a MAF meter. You may also need larger injectors if you're maxing out the injectors as well as the stock ECU.

2001RXX wrote:I The problem I am having is it is leaning out from not enough fuel.

IIRC, it runs two Mikuni carbs, so you could increase the main jet, or fit a larger tube, thinner needle at affected area. Easier than using a MS, and a lot cheaper.

24c wrote:

2001RXX wrote:I The problem I am having is it is leaning out from not enough fuel.

IIRC, it runs two Mikuni carbs, so you could increase the main jet, or fit a larger tube, thinner needle at affected area. Easier than using a MS, and a lot cheaper.

Went up from 162 up to 175 high speed jets and 80 to 90 on low speed and still have the same problem. All seadoo 951 motors have what they call the 3/4 lean out. It has more to do with the air flowing around the venturi then with jets. For a set of novi tec carbs which will fix the problem and give a lot better response and performance are $1500 plus the manifold,air/fuel seperator and what ever else is needed I am looking at about $2000 bucks. I havent added any of the costs up for the MS as right now I am just browsing and looking at how to get everything set up and then figure out if its worth it or not. I know there are a few guys that have done this on some of the smaller 787/800 seadoo motors.

My first thought was to get a set of TB,Injectors and fuel rail from a seadoo DI model. Then use the MS to work the FI

2001RXX wrote: All seadoo 951 motors have what they call the 3/4 lean out. It has more to do with the air flowing around the venturi then with jets.

OK, understand now, but it sounds like this is due to mismatched carbs, an airbox or a snorkelling effect too, which I have seen on special engined quads on the dyno.
Read the rest of your post too, the MS would be cost effective re those carb replacements

24c wrote:

2001RXX wrote: All seadoo 951 motors have what they call the 3/4 lean out. It has more to do with the air flowing around the venturi then with jets.

OK, understand now, but it sounds like this is due to mismatched carbs, an airbox or a snorkelling effect too, which I have seen on special engined quads on the dyno.
Read the rest of your post too, the MS would be cost effective re those carb replacements

Aftermarket replacements. You can find used sets of them carbs but they still start out at 600 and up then you still need all the other stuff. The stock carbs were designed to make them emission freindly so they were designed to use less fuel which in turn sux for mods but on a stock motor you can rejet and go with an aftermarket air cleaner and be ok but as my motor was set at the factory with the twin pipes it is putting out about 160 HP and with the few mods I have about 170 HP. As it stands right now I think the MS would work good once set up and tuned. Would be a lot better for performance and response as well I think.Still trying to find info on tuning to my application.