97 Gti Fuel issues

[Pnut80]

My wife and kids took the Ski out this weekend to ride, and it was messing up on them. it would go for a few seconds then bog down, then back up.. so and so on. then with fuel throttle would only run 20. I am assuming it is fuel related. I just purchased 2 weeks ago. it still has the grey fuel lines (replacing today) . next question is whats best way to drain and clean fuel tank and i have been seeing there is possibly a internal filters in Carburetor? is that correct? I plan on taking carb off and cleaning it too. any thing special i need to know

 

[mikidymac]

Yes, so here we go....
1. Replace all fuel lines with standard automotive 1/4" black fuel hose.
2. Replace fuel strainer and ON/OFf valve, OEM only no aftermarket junk.
3. Rebuild carb with only Genuine Mikuni carb kit and needle and seat, no aftermarket junk.
4. Verify oil is correct API-TC, no blue or green oil.
5. Replace oil filter and small 3/32" oil lines from oil pump to intake manifold (Home Depot Tygon line).

Thanks a good start.

 

[Pnut80]

Thanks,

In process now of getting all related parts.
Oil looks Blueish green that's in the container now. How would i verify its correct

Also. Where is best place to purchase oem online, that way i dont get messed up and get aftermarket

 

[mikidymac]

The easiest one stop shopping is OSD Seadoo Parts.

If the oil is bluish green it it absolutely the wrong oil. You have to run only API-TC oil in these. Yours would do fine with the Seadoo 2T CARB in the Black and white bottle, Lucas has at API-TC 2 stroke oil and so does Mystic.

You can't mix oils so you will have to drain, clean and refill your oil system with the correct oil and replace the oil filter.

 

[Pnut80]

Ok. I put new spark plugs in yesterday and ran on water hose for about 10 mins. Ran great. So I decided to take to lake to see for myself what it was doing. Idled our of no wake zone for 2/3 mins. On main lake we ran it wide open for about 2/3 mins. Then slowed. Once we started back is when the problem kicks in. Throttle held wide open ski ramps up then down then up and down. And so on and on. Then while idling back in it got really rough idling. I plan on doing all the fuel related stuff. But wanted to see for my self what ski was doing. Does this sound like fuel since it’s not all the time? My brother said possibly blown head gasket

 

[mikidymac]

First you can't run it on the hose for than about a minute or you will burn up the driveshaft seal.

If you kept running it like that with it surging I would check the compression because you could have toasted the top end at this point.

If compression is good then move on the full fuel system rebuild.

 

[Pnut80]

I checked compression. It’s 95. But that was before running it the first few times and it ran great. 2 people ran 48. Then flipped it second time out. Blew all water out. And now this. Run at home on hose pipe fine. Take to lake. Runs for a while fine then surges.

 

[mikidymac]

I would use another tester to verify compression before doing anything else. At 95 that engine is done!
150 psi is perfect and 120 is absolutely time for a rebuild.

 

[Pnut80]

Will get another tester. But wouldn’t that make it now run good at all or am I missing something?

 

[mikidymac]

It is more than likely fuel related but if it is starving for fuel could be seizing. A good compression reading will tell you if the engine is ok then you can move onto the fuel system.

 

[Pnut80]

Got another tester. 125 psi.

Gonna go ahead and put new head o rings on it.
Then fuel system

 

[Pnut80]

Got carb off. Top part where choke is broke. And carb is dirty. Looked online for just a new one. But a few different part numbers. How do I verify my carb

 

[mikidymac]

Contact OSD Seadoo. he will set you up with the correct carb and jetting.
I bought one for my GTI from him.

 

[Pnut80]

Thanks for all your help

 

[JeremyD615]

If you’re buying compression gauges from harbor freight, the recent ones all seem to read significantly low for some reason. I bought one not long ago that read 105psi on both my 720 and my 787 ski. I returned that gauge and the second one gave a reading of 115. Since the 720 was running perfectly, I decided to verify with a good gauge, and a snap-on showed 150psi. Now the only thing I’ll use the HF set for is to see if the compression is even between cylinders...

 

[POPPS]

Re:compression, seems all gauges are off, even snapon Most techs agree that what's important is that the cylinders are within 10% of each other. The surging could be the micro filters in the carbs. Many seizures and or partial seizures are caused by plugged or partially plugged micro filters. You can also eliminate a faultering pet cock by running the line to the carb straight from the fuel pickup, (the diaphragm in the petcock becomes mushy and unfortunately is non replaceable). If your intermittent problem disappears that saves you removing and cleaning the carbs. Gray fuel lines definitely will eventually become a point of concern. If you can remove the inline at the carb, and you see green mush, than probably that is also in the micro filters and narrow carb orifices. Re: colour and type of oil. In our race ski (800 cc LTD at 7600 rpm, we used the cheapest synthetic oil that wasn't clear. We have been using Shell Nautilus for years, and the blue colour makes it easier for us to see leaks. The OME is a fortune and BRP doesn't make its own oil.i Sometimes, Walmart sells tc w3 synthetic for sleds in giant 5 litre containers for $40 ish. I'm always having a peek at their oil shelves during off season for bargains. We have never attributed a seizure to our oil, even at Havasu in 95'F air temp. water at 75 F, and rev'in 7600 ish,
did we ever seize. Hope this saves you some diagnostic time and money.