Super Jet [Fixed] Full tank - No problem. 3/4 tank - low end bogging. Here's a noodle for ya.

[Tyrant1919]

So, I've been noticing the last few weeks I'm not able to get the fuel tank completely empty by running it as it starts to bog at about 1/4. Meh no big deal, didn't really think about it, it was time to gas up anyways. Now the last few runs It starts to bog on the low end at about 3/4 of a tank. Mid - high is fine of course. Once I top off, it runs fine. 3/4 bog. top off fine. Rinse repeat. I'm thinking fuel delivery of some sort. I took apart the carbs this morning and noticed nothing wrong. Anybody have any pointers?

 

[Tyrant1919]

B pipe, high comp head, stock tank. No fuel selector, res runs straight to carbs after a filter. Fuel lines run easy, return runs easy. Stumped.

 

[btmboards]

check your tank breather or start with 3/4 tank or when it starts happening open up you gas cap see if it sucks in air. sounds like as you pull gas from the tank the extra space the gas used to be in isnt being replaced with air so you are creating a vacume and you fuel pump is trying to fight is and loosing.

 

[Tyrant1919]

Hmmmm, good point indeed. BRB.

 

[garretonufer]

maybe a crack in the pickup tube, allowing air into the system?

 

[Tyrant1919]

Don't think gas tank is in vacuum. One way air vent is able to suck in air freely.

Dunno if crack in pickup tube. Did pull it out didn't see anything out of ordinary.

Thing runs tits half to full throttle. Just the low end punch only happens about 50% as the other 50% it hardore bogs for a second.

I'll replace the gas and try a new run tomorrow.

 

[smoofers]

Like stated above, check your tank check valve (breather). It should let air IN to the tank, but shouldn't let air out of the tank.

 

[wanderer1]

Water in tank?

 

[Tyrant1919]

I was thinking perhaps water. But why would it magically clean out the water when I throw another gallon in it? Either way I'll replace the gas and see what happens. I checked the spark plug boots/wires too.

 

[btmboards]

those one way valves can get stuck not letting air in.
also open your carb and check your needle and seat and arm than engages it. I have a similar problem because mine wasnt contacting and engaging correctly.

 

[MileHighJSC]

Take your one way valve out. then ride it, just to make sure that is not the problem, also make sure that the line going from the one way valve to the water trap and up the handle pole is not kinked and is clear.

 

[Tyrant1919]

Fixed. Just got back from test ride.

Forgot to put two bolts in flywheel cover after pipe change two months ago. Changed fuel. Broke down carbs again and cleaned/replaced stripped screws with stainless.

I'm betting it was the two bolts in the flywheel.

Thanks for the tips guys!

 

[Matt_E]

It wasn't the flywheel cover bolts.

 

[Tyrant1919]

Hmmm, Well screw me then. Thought that was pressurized, but I guess how could it be with all that crap running into there (Starter, wires, etc...)

 

[Seanc]

It says fixed. Please say what it was to educate everyone else or these threads are fairly useless.

 

[Tyrant1919]

Fix was either new gas or another carb cleaning. Not sure which.

 

[Tyler Zane]

Well it could of been your fuel, your carbs or the 2 flywheel cover bolts... the thread must be useless because no one can hold there hand over the keyboard and magically tell you. Lol just kidding man, it was your fuel and carbs.