Vent tube problem?? (uncorking prob...)

Hey guys.

Just got done uncorking my pig... Worse starting than stock.. ran decent for about 30 sec., then blubberd and died. I was able to keep it going with a little throttle, but it got to the point where any throttle at all would kill it. Now I did remove the vent tubes from the carb (dont ask me why) when I changed the jetting (68s, 175, stock needle with new clip pos.) Im pretty sure the float isnt stuck. Could it be the vent tubes??? I used to love this thing, ran great yesterday when it was still corked.. lol. This is a 400 mile bike..... Ive done a search, and tried almost all of the fixes that folks had reccomended, no avail... :)

You've removed all the other "restrictive" parts also?

I have. :)

Did you adjust the fuel screw afterwards?

Did you change out or modify the intake?

Did you remove 'both' air box restrictors?

Did you also change out the exhaust tip or drill it out?


I was told to leave the fuel screw alone,

changed the intake to the correct part,

yes, both airbox restrictors are gone (dont see how they help to begin with since they arent under the filter...

drilled out exhaust

I went back over everything, made sure there were no leaks or anything like that. Now the pig just plain WONT start to begin with.... Ive increased the idle as well... nothing.. :):D

Still nothing, not even a cough. Damn I knew I should have left this thing stock.. I followed the uncorking instructions to the letter... this is BS :D:):D :D

And there is now an extremly hard spot while im kicking it...almost as if its flooded.. this really sucks.

"dont see how they help to begin with since they arent under the filter..."

Look at the filter assembly a little closer -

Pull the carb apart and check where the needle is sitting - and put the vent tubes back on.

Turn the fuel screw in to see if there is a change.

Relax - it's worth the trouble.

Pulled the carb out about a half hour ago, everthing is good in the carb. I put all the vent tubes back on, put the carb back in, still nada.... The fuel screw is at about 2 turns out.

FlyByWire - I was helping a friend uncork his pig a month back, and something that sounds pretty similar happened to us. Thing would barely run unless we were giving it throttle, and it wanted to die badly. Likewise, the only way we could get it started was with the choke on, and that was once in a long while. Anyway, it turned out to be an air leak; in our case, the o-ring for the top of the carb somehow managed to get pinched during install, which caused all these problems. My suggestion would be to disassemble the carb and check the carb cap and floatbowl o-rings for any pinching on them, and as a precaution, purchase the carb o-ring set from honda and replace those (it's like ~17.00). My friend was feeling the exact same way as you, until we replaced the gasket. Now he says the aggrivation was "a little price to pay." Keep us updated. :)

I looked at that when i had the carb out the last time as well. I thought that was the problem to begin with. I'll pull it out and double-double check it. Its not starting to begin with.....

pulled the carb again, o rings are good, no leaks... still no starting, nada, no coughs or anything.... :D:):D :D :D :D :usa: :usa: :D

Is it leaking gas too? Got a rag stuck in the airbox...something? Very strange though very simple problem. Put the vent tubes on(in the right location. Make sure the one that rides up near the seat isn't pinched or the one that hangs by the swingarm. Check the pin the rides on the float "tang". It blocks the main gas line when the float level reaches it's proper height. This can get caught and protrude out of the main gas line rather than in the hole like it should. Thus leaking gas and not starting.

Are you sure it's flooding?

Have you checked for good spark?

Assuming you are getting good spark, it sounds like your float level isn't allowing enough gas into the bowl for the vacuum to pull it up into the carburetor throat.

Do you have a manual to check this? If not, go to

maybe it is flooded. If it is soooo flooded that it's causing it to kick over hard, you'd better either let it sit or clear it out with the spark plug out before proceeding. It is possible to bend the connecting rod if you force it to turn over when it's really flooded.

Anyway, i'd think it would be a good idea to see if the plug is wet.

By the way , it's possible for the plug to be wet and still the engine doesn't have enough gas. This is related to the compression ratio and the ability of the fuel to evaporate and form a charge that can be burnt by the engine.

I had a similar problem. This may or may not work for you, but it seemed to work for me. (after about three trys) Check your float level. If it is flooding very bad, you should be gettting gas out your overflow vent tube. If your float level is too low (not enough gas) you could be starving your pilot. Pull the spark plug, and clean it with a small wire brush, and some brake parts cleaner or something.

Then check your float level. I'm not sure on the technical method, but with the carb off, float bowl removed, hold the carb up-side-down. With the carb in that position, push down the floats. You should get light/firm resistance about 1/8 of an inch before the floats bottom out on what would be the top inside surface of the float chamber. When you stop pushing on the floats, they should spring back slightly.

Starting: With all of this done, and the bike re-assembled, put the choke on full, no throttle, hold in the compression release and kick it four or five times. Then release the compression release and kick it through with it's usual compression. Again, I am new to the four stroke world too, but through trial and error, and the good advice of the guys in this forum, I think I have a set-up and starting method that works. Let us know how you do!!

Gary :)

OK, nobody has mentioned this one. I know this probably goes without saying, but is your GAS turned on? With the tank coming on and off, it is easy to forget the simple things.

Have you tried roll starting it?

When I changed my carb out for the Edelbrock I also had a similar problem. It turned out that the idle was all the way off and it would not start to save my life. I was cursing the heck out of it. Finally got it started and realized that the idle needed to be higher. That might also work.

Good luck and if it does not work, I'll take the bike off your hands.

No, there isnt anything clogged. The float level hasnt changed.. The thing I dont understand is it ran great yesterday before I uncorked the thing, and all I did was change the jets and needle. About the only thing I havnt done is check for spark, i guess i just ASSumed that it is good because again, it ran great yesterday. hmmm :)

I really do appreciate all the help so far guys..


O..K Ive got good spark,plug isnt wet... still nothing... :)

I think I may have a float problem, With the carb upside down, the float rests on the inside of the bowl, there is no resistance. I have the shop manual, but am still unclear on what i need to adjust, if anything.

The plugs not wet...............Hmmmmmmm. is it getting fuel ? :confused:Try spraying starting fluid in the intake while kicking it.If it starts (or almost starts)then you have flubbed something up.Minor jetting changes wont keep the bike from starting.Maybe you should enlist the help of someone who has more mechanical knowledge than yourself :)

Next time one of you guys see me, you need to give me a good hard kick in the ass.... lol. Follow me... So I pull the carb for the elevendyth time... everything is fine, put the tank back on.. still wont start. So I think to myself, maybe i'll put the fuel switch to reserve, Ive tried everything else.... FIRST KICK.. BWAAAAAAAAAAAAAAAAA :D :D... got the idle calmed down, and she ran like a champ. You guys think with taking the tank on and off and on and off... maybe the fuel allll went to the left side? (this was a full tank with 35 miles burned) God I feel like such a lame ass :D :D.... But thanks for all of your suguestions...This place is REALLY great!!

Brett :):D:D

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