Dental ultrasonic cleaner defeats balky, clogged up 717 Mikuni carbs

[Nathan Mayo]

My '97 Speedster has been giving me the fits, so I caved in and took it to my local Seadoo dealer. Several of the local shadetree mechanics have failed. Greg, the head dog at Seminole Powersports, is a knowledgeable prince of a guy and has the tenacity of a bulldog. He discovered 2 clogged up accelerator valves and could not clear them. Since they are $200 each X 2 to buy new I tackled the job with my office ultrasonic and managed to clean them up after 5 solid hours of buzzing with carb cleaner and PB Blaster, followed by white vinegar and Limeaway. My latest effort tonight was 4 more hours on one of the carb bodies. I think the passageways are now totally clear, but he will have to reassemble and put it in the lake to test.

I realize that most people do not have access to such a device and they cost several hundred dollars for a good one, but all dental offices have them. You should all be on good terms with your personal dentist anyway, so maybe if he is an understanding boat lover he could let you come over and use his. If not, maybe some motor shops have them. If this all goes well I will try to talk Greg into getting one for his shop. I suspect a lot of carb problems could be solved fairly easily with one of these gadgets.

Carb cleaners mainly work on organic gunky stuff...........my problems were caused by calcium deposits or aluminum corrosion products in some very tight little crevices. Acid wash and ultrasonic is the only thing I could think of that would have a chance at loosening them up.

 

[Sportster-2001-951C-Stock]

Good job man! I believe the accelerator nozzles are brass with a check ball and spring so maybe the check balls were a bit rusty (should be stainless) or as you said mineral deposits.

Won't know for sure till you get her out there but clogged a-pump nozzles likely will cause hesitation during acceleration. Those tiny pilot passages in the carb bore seem to give people fits too, mine did that to me (SBN46i).

 

[ialonso]

BN-4038x24 for my 717 can be found NEW from $160-200 each WHOLE. Look for options on Mikuni carbs that are not directly catering to SeaDoo and you may be surprised.

 

[Nathan Mayo]

Where would I find these carbs? I May need this tidbit of info if my latest cleaning effort fails the lake test. I failed to mention above that those accelerator valves required persuasion with some heavy gauge SS wire and a hammer to persuade those little balls to move.......even after all the ultrasonic work

 

[ialonso]

So, they don't sell a Mikuni carb with that main jet out of the box... It is 182 which is huge compared to what's on my 1999 Sportster 1800.

You would need to buy a BN-4038-24 and replace the main jet to one sized at 182.5. Seems your boat uses built it fuel pump on the carbs (pulled up microfiche online). Is this accurate?

I can see them for under $200, but you do need to replace the jet with the correct size. Google BN-40i3824 Mikuni

Good Luck!

 

[howie099]

OSD sells new carbs at a very good price. They usually will change the jets for you if you know what you need.

 

[ialonso]

OSD sells new carbs at a very good price. They usually will change the jets for you if you know what you need.

And the jets are specified on the Microfiche for SeaDoo, and can also be read from your existing carb.

 

[Nathan Mayo]

Here's hoping.......

And the jets are specified on the Microfiche for SeaDoo, and can also be read from your existing carb.

Greg emailed me today that the carb appears to be clear throughout and will be heading for the lake test......hopefully tomorrow......and I will be dancing in the street......or setting fire to a boat......could go either way.

Thanks for the info!

 

[ialonso]

LOL, that's where I was with carbs before replacing them entirely with brand new, and adding spin-on metal canister filters. Best money I ever spent on the boat.