Hard to start, won't run on low RPM

[darrylmccaw]

I just re-built my carbs on my 94 GTX, before they were rebuilt it bogged and wouldn't go anywhere!

I put new needle and seats in (2.0), checked the pop off pressure and it was about 23-26 in both carbs.

I also replaced all of the fuel hoses and have bypassed the fuel selector valve and the stock fuel filter (I put an inline filter on).

I turned out the low adjuster 3/8 and the high 1 1/4 as per Sea Doo PWC Carburetor Reference

This weekend I had it out, really hard to start (had to have throttle wide open and choke had no effect) and it idled rough and at low speeds it was terrible. Once you hit about 1/4-1/2 throttle, it took off like a jet and ran significantly better then before I rebuilt the carbs (more power and plenty responsive).

Any suggestions would be great before I take it all apart again!

Thank you all!

 

[mikidymac]

First get rid of the inline filter and go back to the stock strainer with a new o-ring. THe inline filters cause issues.

Second what carb kit did you buy? Did you change out the spring?

 

[JeremyD615]

Agreed. The filter needs to go ASAP. It’s also incredibly important that you used genuine Mikuni rebuild kits. Any other brand, and you need to pull the carbs and do the work over again.

Also, it’s either a typo on your part, or very likely your problem, but the low speed adjuster should be 1-1/4 turns out and the high speed should be 3/8. You’ve got them backwards the way it’s written...

 

[darrylmccaw]

Thank you for your reply's....

Crap, I think that is the problem..I looked at that low/high webpage so many times my brain saw what i wanted it to see... I'm pretty sure I only turned low out 3/8 and the high out to 1 1/4!!!! That would make sense!

Just curious though, what issues are caused by an inline filter. I will be getting a new O-ring and running the lines back through the stock filter before I take it back out.

Thanks again for your help, very much appreciated!

 

[noviceskier]

they restrict flow and can cause a lean condition, the fuel strainer works awesome and separates from water too which is good because you should only be riding in water haha. Also pretty cheap to just buy a brand new oem one too.

 

[darrylmccaw]

just a quick update... the settings on the high and low were correct (so I'm not an idiot!)...I got rid of the inline fuel filter...turned up the idle a bit... went to start...needed full throttle to start...still hard to start.

I used the same lever and spring that was already installed, but replaced the needle and seat. I didn't use genuine mikuni parts, would it run so nicely at high speeds if the rebuild kit was bad?

I also use mixed fuel, the guy that rebuilt the motor last year said the oil pump was shot (hence I lost a cylinder).

Guess, I'll just take it out on the water one more time, and if the problem continues, I'll order a new rebuild kit and pull the carbs. Unless anyone has any other suggestion!

 

[JeremyD615]

You need to pull the carbs and replace the aftermarket parts. You’ll be chasing this thing forever until that’s done... I’d also highly recommend that you get the oil pump set back up. There are quite a few guys that have been working on these things for decades without ever seeing a single pump failure. They’re super reliable, and you’ll use much less oil overall...

 

[mikidymac]

Agreed, you'll be chasing your tail all summer with those aftermarket carb parts.

Order the "Back to stock" kits from OSD seadoo and enjoy your ski.