Carb issues 1997 gtx

[jonofranke]

Hey guys

I’m really stuck with this one and want some advice before I rebuild the carbs

I have a 1997 gtx, not been run in years bought it of an old fella with no mpem.

Chucked a new mpem in and took apart the carbs to check them out. There was a fair bit of water/oil mix in them with a bit of rust.
The rubber diaphragms were slightly eroded on the sides with white stuff? But no holes so decided to clean it all up and put it back together.

Started it up eventually but it never ran great. I would have to add fuel manually to get it started sometime and other times it would start no issues. Normally when it was warm.

When throttled it would hold it at the rev you took it to despite the throttle going back to normal. Sometimes it would keep reving up and I would have to choke it or put the lanyard.

Decided to take carb apart again to inspect.

Gave it a good clean noticed the diaphragms one was slightly stiffer than the other. Did a pop test on both and where popping at 35-40

Put it back together and had the same issues. Found that if the mag side carb was choked a fair bit it would run better with no hanging or stalling.

Ran it on the water like this for a bit but there wasn’t much high end power it didn’t rev that high( I assume because one carb was choked)
The mag side carb seems to be sucking in heaps of air compared to the other. It is noticeable with your hand on the inlet.

Any ideas what it could be to cause these symptoms? Bad fuel pump? I swear it’s getting air from somewhere else but im stumped as to where. Gasket to block is good I replace them. And it’s only the MAG side carb that seems to need to be chocked.

Butterfly vv is good too

150 psi cold on both pistons

Need a fix fast cause the missus is getting mad at the amount of time I’m spending on it hahahaha
Cheers

 

[mikidymac]

Stop riding it or you will blow it up.
Rebuild the carbs correctly now or don't even bother messing with it.

Everything you need to know is here... The Seadoo Carb Rebuild Thread

 

[jonofranke]

Some forums reckon it could be a leaky crank seal what would the likely hood of this be? There’s a bit of “blowby” on the balancing shaft oil filler when it’s open and it’s running. Would this indicate blown seals? Lots of contradicting info about this some say it’s just a labyrinth washer which allows fuel oil in as a lubricant

 

[etemplet]

With all due respect to other forums and even people.... many just repeat what they hear or their own experience which is slim to none. You have two problems that need attention. 100% rebuild on the carbs with a "return to stock" kit. Everything must be replaced. The carbs need to be soaked in Chem dip or ultrasonically cleaned. Those 4 ports in the middle of the throat need to flow freely. After rebuilding the carbs I'll pull the rave valves and clean them up. Might be some gunk in there and it never hurts to clean them up. Watch you don't loose the spring.

I'd also replace the fuel lines and check the fuel selector valve for leakage. Lots of people would just replace it.

Give the ski some love and attention and it will reward you with reliability and good fun. Preventive maintenance is much cheaper than repairs. LOL My skis get a couple hours of attention "before" we go ride. Good Luck !!

1996 and 1997 GTX.

 

[mikidymac]

Some forums reckon it could be a leaky crank seal what would the likely hood of this be? There’s a bit of “blowby” on the balancing shaft oil filler when it’s open and it’s running. Would this indicate blown seals? Lots of contradicting info about this some say it’s just a labyrinth washer which allows fuel oil in as a lubricant

Do not ever run that ski with the balance shaft plug out. Whoever told you that is a complete idiot as you have just created a massive case air leak. That cavity is open to the PTO cylinder crankcase, there is no seal separating them. The oil has to go through the bearings and a washer but that’s it. The oil is used and replaced from the oil/fuel mixture. It’s only there to get water out if you ingest water.