Fuel coming out of flame arrestors

tipafew

tipafew

Location
Grand Rapids, MI
I am having an issue I have never had before. Since I have installed my TPE 964 I always have tons of fuel//oil all over the top of my motor that appears to be coming from the flame arrestors. I am running Mikuni 46’s and OEM flame arrestors.

After every ride it’s an absolute mess. At first I thought it was coming from the exhaust or power valves but now I’m pretty sure it’s coming right back out of the flame arrestor.

Any ideas of cause? The ski runs flawless.
 
tipafew

tipafew

Location
Grand Rapids, MI
Wetbuffalo said:
What reeds? And are the fuel pumps close to the motor or on the far side close to the hull?
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VForce 2's I believe if memory is correct. They looked pretty good last time they were out but definitely not new. Fuel pumps are hull side.

The part that has me a little baffled is that the ski runs so PERFECT. I would think reeds would give me some type of indication of there being an issue.
I am going to play with it some more this weekend and see what I can come up with.
 
Wetbuffalo

Wetbuffalo

Location
New York
tipafew said:
VForce 2's I believe if memory is correct. They looked pretty good last time they were out but definitely not new. Fuel pumps are hull side.

The part that has me a little baffled is that the ski runs so PERFECT. I would think reeds would give me some type of indication of there being an issue.
I am going to play with it some more this weekend and see what I can come up with.
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My brand new v-force reeds do the same thing as my 2 year old ones. They leak. They are just a poor sealing reed. They float at low rpm and do not seal 100%. If you have any kind of fuel dribble, the blow back throws it all over the inside of the hull.

Not to feed the pop off people but lower pop off carbs have this behavior amplified. My ninja carbs were so bad until I stopped following the normal tuning recommendations for pop off and raised it.
 
tipafew

tipafew

Location
Grand Rapids, MI
I used these reeds on the last motor with no issues but the carbs are new. Could def. look at pop off. That could be part of it. It sure makes a horrible mess!!!
 
tipafew

tipafew

Location
Grand Rapids, MI
It was used but freshly rebuilt top to bottom by Paul Lehr. I talked to Paul about it and he said it was basically a new motor. I only ride for about two months each fall when the waves are good on lake Michigan. I ran it last fall then maybe 3-4 tanks so far this year and have had the same problem the entire time.
 
Quinc

Quinc

Buy a Superjet
Location
California
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fastgtfairlane

fastgtfairlane

Location
Charlotte, NC
Are the returns drilled out and the tee tapped for a mikuni main jet to adjust your fuel pressure? If not, that might be something to consider. I know it adds another thing to tune and recommend getting a fuel pressure gauge and taking the time to do buy it could definitely help your issue especially the shaking at idle. I had the same issue on my 735 with dual 44s and adjusting fuel pressure helped the shaking idle quite a bit. Definitely worth talking to Paul about as well.
 
tipafew

tipafew

Location
Grand Rapids, MI
fastgtfairlane said:
Are the returns drilled out and the tee tapped for a mikuni main jet to adjust your fuel pressure? If not, that might be something to consider. I know it adds another thing to tune and recommend getting a fuel pressure gauge and taking the time to do buy it could definitely help your issue especially the shaking at idle. I had the same issue on my 735 with dual 44s and adjusting fuel pressure helped the shaking idle quite a bit. Definitely worth talking to Paul about as well.
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Well, My returns are NOT drilled out but I do have a jet in the return T. I do have a automotive fuel pressure gauge. You are right.....I should talk to Paul. I will fire him an email.
 
Pro-pulsion

Pro-pulsion

Location
Ontario, Canada
Have a look at the the vent hole on the carbs where the metering diaphragm is (the black round disc inside). I had a brand new SBT kit lose it's crimp? vulcanizing bond? not sure how they're held together, but where the center post is to actuate the needle valve, that became independent of the diaphragm. I noticed fuel was spraying out of that atmospheric vent for the diaphragm. When I pulled the thing out, you could hold that post and spin the diaphragm like a frisbee. Fuel was sneaking past that center post sealed bond and being ejected out the vent hole. It did the same thing to his engine, absolutely soaked it in fuel.
 
tipafew

tipafew

Location
Grand Rapids, MI
Pro-pulsion said:
Have a look at the the vent hole on the carbs where the metering diaphragm is (the black round disc inside). I had a brand new SBT kit lose it's crimp? vulcanizing bond? not sure how they're held together, but where the center post is to actuate the needle valve, that became independent of the diaphragm. I noticed fuel was spraying out of that atmospheric vent for the diaphragm. When I pulled the thing out, you could hold that post and spin the diaphragm like a frisbee. Fuel was sneaking past that center post sealed bond and being ejected out the vent hole. It did the same thing to his engine, absolutely soaked it in fuel.
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That's crazy. It's not coming out that vent hole at all. That side of the motor actually stays fairly clean. With the OEM F/A it seems to come out and dump right on top of the head.
 
Pro-pulsion

Pro-pulsion

Location
Ontario, Canada
Yeah I try to get everyone to avoid SBT kits after that lol. For a long time Mikuni kits were reacting negatively to the fuel we have here. It made the o-rings swell at least 30% and made putting them back in impossible until they dried out. Either Mikuni changed their kits to deal with that or the fuel quality up here has changed because I don't see that happening anymore. WSM kits believe it or not, were my go to. I still have them in my old 38's and they still work very well, not diaphragm issues...yet lol. But now that the Mikuni kits are better, or the fuel...whichever, I go back to recommending Mikuni all the way. I almost wonder if you're having a fuel dribble issue that's getting sent back up. Iunno, I just work here :p
 
Sparkplug

Sparkplug

Location
Red Bluff CA
I dealt with Novi 48s and the same issue for weeks. Talked to multiple "experts" even the guy who "built" the carbs

Ended up trial and error of basic carb theory. That was 2 seasons ago and my carbs haven't needed touched since. To my own specs

Grain of salt. All of it.
 
fastgtfairlane

fastgtfairlane

Location
Charlotte, NC
tipafew said:
Well, My returns are NOT drilled out but I do have a jet in the return T. I do have a automotive fuel pressure gauge. You are right.....I should talk to Paul. I will fire him an email.
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Try taking the jet out if the internal restrictors are not drilled and see what happens. The purpose of the jet in the tee is to equalize the fuel pressure between the 2 carbs. If they're not drilled out then I'd imagine the jet I'd causing a fuel issue.
 
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