Waveblaster 1 can’t tune high jet

J

Jetskijunkee

Location
Tennessee
Waveblaster 1 was running fine. Only upgrades before the pipe is lightened flywheel and a carburetor that someone removed the choke flap to. I put a mod bpipe on it and now I can’t tune the main jet. I even drilled out a old main jet to some ridiculoilus size and drilled an old seat out and still couldn’t get it to bog down. I rebuilt the carb with Minkuni kit and replaced the needle and seat as well.
150 main
115 pilot
2.0 seat
So after all that I tested the ski for a leak. I brought he air up too high on accident and may have blown the rear seal out but it leaked there so I split the case and put new seals in. Tested today will carb setting shown above. Three turns out on pilot and main and runs just fine. Will not bog down. I did cover the top of the carb with my hand tighter than I meant to when first starting it. Im wondering if that pressure may have made a seal leak. Idk Any help will be appreciated usted. Sick of this poop.
 
Sparkplug

Sparkplug

Location
Red Bluff CA
What made you decide to run a 2.0 seat? Not sure why anyone would do that on a sub 1000cc engine.

What is the popoff? I have a blaster set the same but I run a 145. 1.2 turns out. 38psi popoff
 
kevbo

kevbo

Location
dfw
I like to run 2.0N/S on single carb intakes just because a drop in fuel pressure will make a 1.5 act as the jet, which is smaller than the restrictions up stream.. In theory having a constant 5psi at the N/S would allow for a much smaller one.
 
J

Jetskijunkee

Location
Tennessee
kevbo said:
I like to run 2.0N/S on single carb intakes just because a drop in fuel pressure will make a 1.5 act as the jet, which is smaller than the restrictions up stream.. In theory having a constant 5psi at the N/S would allow for a much smaller
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Could holding your hand over the top of the carb create too much pressure and blow a crank seal?
 
kevbo

kevbo

Location
dfw
Jetskijunkee said:
Could holding your hand over the top of the carb create too much pressure and blow a crank seal?
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Your engine can create only around 6psi in its crankcase. The only way it can blow out a seal is by having a lot of liquid inside or by having a loose grip between the seal and crankcase. Its unlikely liquid caused the problem since enough of it would get blown into the cylinder and cause a hydro lock very fast. I believe seals blow from poor prep or they fit too loose to begin with. I clean them squeaky clean and use OEM, so far none have ever blown out.
 
J

Jetskijunkee

Location
Tennessee
kevbo said:
Your engine can create only around 6psi in its crankcase. The only way it can blow out a seal is by having a lot of liquid inside or by having a loose grip between the seal and crankcase. Its unlikely liquid caused the problem since enough of it would get blown into the cylinder and cause a hydro lock very fast. I believe seals blow from poor prep or they fit too loose to begin with. I clean them squeaky clean and use OEM, so far none have ever blown out.
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I just replaced and tested these crank seals. They held at 9psi. This has to be a air leak, right? Why else would I not be getting enough fuel?
 
kevbo

kevbo

Location
dfw
Air leaks wont affect a PWC as badly as they do a motorcycle. Jetskis are always under an increasing load from idle to full rpm and the rpm drops instantly when the throttle is closed. Air leaks cause motorcycles to burn a piston (mostly) while at part power and while coasting. Try tying the ski down to the trailer and sink it as deep as you can with the hood off. With the top adjuster 2 turns out hold it full throttle and put your hand over the carb inlet and choke it enough to make the engine slow down. If you can do this then enough fuel can get through the carb. Make sure the pulse line is not cracked or plugged. Make sure fuel is coming out of the return line at all times, if its not then you have a pump side problem. Make sure the carb basket is clean. Make sure the tank is venting!! You should be able to slow the engine at full throttle with a combination of main jet and top screw. Hope this helps.
 
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Pro-pulsion

Pro-pulsion

Location
Ontario, Canada
Rebuild the fuel shut off valve too. There's an o-ring inside that over time will wear out and either leak or allow air into the fuel supply hose leaning out the fuel. Also check for excessive play at the throttle shaft bushings. When worn out they'll bring in a lot of unwanted air making tuning a real nightmare.
 
J

Jetskijunkee

Location
Tennessee
Pro-pulsion said:
Rebuild the fuel shut off valve too. There's an o-ring inside that over time will wear out and either leak or allow air into the fuel supply hose leaning out the fuel. Also check for excessive play at the throttle shaft bushings. When worn out they'll bring in a lot of unwanted air making tuning a real nightmare.
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Ok. I bypassed the fuel shutoff when I built it 3years ago. I’ll check the throttle shaft though. I won’t be able to check it for over a week but I’ll let you know if I find anything. Thanks
 
J

Jetskijunkee

Location
Tennessee
kevbo said:
Air leaks wont affect a PWC as badly as they do a motorcycle. Jetskis are always under an increasing load from idle to full rpm and the rpm drops instantly when the throttle is closed. Air leaks cause motorcycles to burn a piston (mostly) while at part power and while coasting. Try tying the ski down to the trailer and sink it as deep as you can with the hood off. With the top adjuster 2 turns out hold it full throttle and put your hand over the carb inlet and choke it enough to make the engine slow down. If you can do this then enough fuel can get through the carb. Make sure the pulse line is not cracked or plugged. Make sure fuel is coming out of the return line at all times, if its not then you have a pump side problem. Make sure the carb basket is clean. Make sure the tank is venting!! You should be able to slow the engine at full throttle with a combination of main jet and top screw. Hope this helps.
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So I took the blaster to the lake today and did as you said. Full throttle I can put my hand over the top of the carb and bog it down without killing it. I also still get fuel on the return line as well. Just a little dribbles out at full throttle but I assume that’s normal. I cannot get it to change rpm just by adjusting the high speed adjuster at full throttle though. Idk what is going on. I plan to check the pickup tube in a min
kevbo said:
Air leaks wont affect a PWC as badly as they do a motorcycle. Jetskis are always under an increasing load from idle to full rpm and the rpm drops instantly when the throttle is closed. Air leaks cause motorcycles to burn a piston (mostly) while at part power and while coasting. Try tying the ski down to the trailer and sink it as deep as you can with the hood off. With the top adjuster 2 turns out hold it full throttle and put your hand over the carb inlet and choke it enough to make the engine slow down. If you can do this then enough fuel can get through the carb. Make sure the pulse line is not cracked or plugged. Make sure fuel is coming out of the return line at all times, if its not then you have a pump side problem. Make sure the carb basket is clean. Make sure the tank is venting!! You should be able to slow the engine at full throttle with a combination of main jet and top screw. Hope this helps.
Click to expand...
 
J

Jetskijunkee

Location
Tennessee
Jetskijunkee said:
I’ll try a 150 tomorrow. Thsnks
Jetskijunkee said:
Ok. I bypassed the fuel shutoff when I built it 3years ago. I’ll check the throttle shaft though. I won’t be able to check it for over a week but I’ll let you know if I find anything. Thanks
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There was some play in the throttle shaft. I took the shaft apart on the cable side and put grease in there with the seal. I think that may have been the problem. I went up to 155 on the main jet and now with the grease am able to tune at almost 2 turns out. This seems accessible. Do you know where I can order those seals from. They don’t look like orbits more like a tiny seal
 
J

Jetskijunkee

Location
Tennessee
Pisser was steaming. Head gasket was not leaking on the outside but appears to be leaking internally. Water appeared to be on the pistons. Will replace head gasket tomorrow and most likely rejet I’m guessing.thanks for all the help.
 
kevbo

kevbo

Location
dfw
Look for a sputtering broken pisser stream, that means there is combustion gas leaking into the jacket. If the stream is solid then there is no leak. Its common to see smoke from the pisser when no water is flowing. Its also common to see condensation on the spark plugs in certain conditions.
 
J

Jetskijunkee

Location
Tennessee
kevbo said:
Look for a sputtering broken pisser stream, that means there is combustion gas leaking into the jacket. If the stream is solid then there is no leak. Its common to see smoke from the pisser when no water is flowing. Its also common to see condensation on the spark plugs in certain conditions.
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The water was scalding hot and steaming out of the poster. I pulled the head and one piston was completely clean the other very little black on it. Looked like water on the piston. The water has never been that hot before. I’ll put a new gasket in today and see what happens. Only have cheapo head gasket though.
 
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