96 GTi swamped

[JDCam]

Hello all,
The kids rolled my 96 GTi yesterday and swapped the engine. I pulled it out of the water, pulled the plugs, & ran the water out of the cylinders. Was able to get it restarted without much trouble. Its starts easy and runs nice up to 3/4 throttle. If i go any faster it feels like its starving for fuel and cuts in and out. Ran it in water for about 15 mins but no improvement. What have i missed?
Cam.

 

[JDCam]

Have about an hour on it now. Was hoping if some water in the carb it would eventually pass through. No improvement.
Maybe water in one of the filters?

 

[Ckrawiec]

Yes, most likely...open up the fuel pulse pump and see if it’s clear of water....mag side carb closest to front of ski

 

[JDCam]

Thanks. When you say 'open', do you mean pull the supply line, or actually remove the top? If so i should likely have a gasket kit ready to go.

 

[POPPS]

CK is right, you may have some water in the fuel pump diaphram. It may not be easy to access, you may have to remove the air box.

 

[JDCam]

Ok...so i opened up the front pump. The diaphragm is used of course but no signs of damage. I took the small fuel filter out. Looks fine. Wiped everything down and reassembled. Machine is still running the same, any more than 3/4 throttle and it starts cutting out.

 

[mikidymac]

Did you check the fuel pump side of the carb?

 

[JDCam]

Hi Mikidymac,
I am not clear what you are asking.
I had checked the 'pulse' fuel pump attached to the side of the front carb as Ck had suggested.

I want to add this....although it ran fine before it got flipped, the cutting out at high speed feels very similar to what happens when I get low on fuel. When I switch to reserve there is no improvement. As soon as I fill the tank it runs great again. I was thinking my selector or reserve line was blocked/failing but had not yet investigated this. Is it possible this is related, and the flip/swamp has further damaged it?

 

[JDCam]

Update...I am back up at the lake to give it another shot. Now it wont start at all. If i put a bit of fuel in the sparkplug hole it fires right up for a few seconds .... I assume it is a fuel issue.

I pulled and inspected the filter. After a few cranks the bowl was refilled. I think that would that indicate the pump is drawing fuel.

I started to reopen the front pulse pump and fuel leaked out, so again i assume the fuel is getting that far.

So whats stopping it from getting to the cylinders? Am i right to conclude the issue is in the pump or carbs and likely needs a cleaning and rebuild?

Anything less drastic to try before doing a rebuild?

Any comments are appreciated. This is my first 2 stroke and i don't really know what i am doing.

 

[benjilafouine]

Have you done a compression test before anything else? If it cranks and your battery is good, this is what I would do at this point.

 

[mikidymac]

Carb rebuild with only Genuine Mikuni parts.

 

[JDCam]

Thanks... i expected a carb rebuild was going to be needed.

I took a look online for the Mikuni kit, and the options are a little overhelming. Worried i get the wrong kit. My ski is a 96 GTi with 717 engine. I think that makes the carbs BN-38I(SB). Is there a way to physically verify the carb model?

2 carbs = 2 kits? And are both carbs identical or each need different kits?
If someone could pass me the correct Mikuni kit number, i would be very greatful.

 

[Ckrawiec]

Yes, 2 carbs = 2 kits.....if you're going in, go all the way in. I believe your carbs are the square body BN-38 series...so searching by the year and model of your ski should get you the proper MIKUNI kits (Amazon, etc...). Don't go with any aftermarket kits that say ...just like OEM...they a'int. If it's not mikuni, it's not mikuni...period.

Follow the Mikidymac Carb rebuild sticky post to the letter, no shortcuts...and you should be back in business.

Figure about $50.00/carb in that neighborhood (the kits will probably have more parts than you'll need, so don't worry about the extra pieces, but keep track of the uber tiny plastic flap check valves (as they are there but almost invisible and very easy to miss))...you might also consider new needles and seats....there are some carb kits out there that have them, some not.....I've purchased them separately (Amazon again)...

 

[mikidymac]

You can get everything at OSD seadoo.