1998 GSX limited starting issue after sitting for a while.

[Texwing]

I have a new to me ski, in great shape, but after it sits for a few weeks, its not going to start. I can pull the plugs, inject a few cc's of premix into the cylinders, replace plugs, and it will fire right up and then run really well. It will then start easily when warm, and the next day it will still start, with some grief.

As far as the starter, when cold it will somewhat randomly turn over pretty fast to pretty slow. Barely turn over a time or two, then rapidly turn over for a few seconds, its oddly random. New Battery installed.

So it seems to be some issue after sitting, with fuel getting into action-I guess the direct injection of premix gets it all moving fast enough to "prime". Any thoughts on what to look for appreciated.

 

[XP 787]

Carbed 951 in that ski right? If so are you using the choke on a cold start?

 

[mikidymac]

Next time try opening the gas cap. If it doesn't hiss you could have a leak int he fuel system and the loss of pressure could cause a loss of prime in the fuel lines.
Also that model has an accelerator pump so about 5 pumps of the throttle will prime it just like you have been dumping fuel in to get it started.

 

[Texwing]

Wow great info thanks! Yes i am choking it, but get no coughs or sputters, plugs seem gassy but may just be oily. It is a carbed 951. Would the hiss i should hear be pressure, or vacuum? Don't recall a hiss but will start listening. Great info on the accelerator pump, I will try that! all this fuel injected stuff now has caused me to forget carb management from yesteryear.

Any thoughts on the random speed of turning over when cold? when warm it fires instantly.

 

[mikidymac]

It is possible that your needle and seats are leaking fuel and that would flood the engine and make it hard to start after sitting. Although pouring more fuel in would make it worse, not fire immediately.
When were the carbs rebuilt last?

 

[Texwing]

It is possible that your needle and seats are leaking fuel and that would flood the engine and make it hard to start after sitting. Although pouring more fuel in would make it worse, not fire immediately.
When were the carbs rebuilt last?

Well, long story on this ski, got it from a friend who always took it to the dealer and spent a fortune on it, including allegedly a new engine. Carb rebuilding unknown, but once started the first time, runs and idles great. That first start up after sitting is the issue.

 

[mikidymac]

Yes but if the needle and seats are slowly leaking it will flood the engine when sitting for extended periods of time and be difficult to start.

If it were me I would never guess and chance carbs as they are the most common thing to burn down a seadoo engine.

 

[Texwing]

Yes Sir I think I will need to, it's running now a bit rough in the low ranges. On the other hand, it's starting well.