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carb spitting an smell of gas

tonys fatboy

tonys fatboy

Member
i have a 96 fat boy after having it dynoed an jetted its still spitting through the carb the carb seems dry at touch but my pants leg is now getting covered in gas dealer said it wasnt doing it when they jetted it jets were off still runs good but every now an then itll spit when down shifting or up shifting could use some help dont have another $500 to waste on it not getting fixed...
 
What did you do to the bike to warrant a Dyno? What type of carb. are you running, S&S,stock CV, Mikuni? Do you know what jets sizes you ended up with? Little more info could help.

tourbox
 
bought the bike from a friend who was in jail he put different pipes on an said he rejetted the bike its a stock carb bike has 70,000 miles on it it runs good but was spitting in between shifts an smelt of gas took it to the dealer for other issues an to have it gone over bike sat for a while .. The dealer said all bikes smell of gas My 65 panhead didnt smell of gas lol so they said best way to resolve the issue was to dyno it so they said afterwards the jets were to big I beleive there now 45/190? bike runs alot better but still smells of gas an spits once in a while they also said the intake gaskets had some sort of glue on them they cleaned the carb put new seals changed the plugs adjusted the carb the 1st base pull was max power 52.5 hp an max torgue 62.23 after new jets an tune up an adjustment last pull was 55.10 hp an max torgue was 64.13 not really worth the money in my eyes but i was curious either way they the dealer also said it had a cam an the pinion gear was the wrong one whining noise i didnt care was thinking of refreshing it next season go a little bigger more hp . but now when we get back from all day riding my pants leg is covered in gas . The original owner said he believes its an intake leak... i have not even took a wrench to it yet put 3500 miles on it replaced the engine oil with Dynocycle oil which i have felt the difference in hp an makes the bike run cooler .. soo i hope someone could maybe have an idea of what might this be thank you for all your help....
 
You said the bike sat for a while. How long was that?

Do you know if the HD dealership rebuilt the carb with all new gaskets and seals including the slider and diaphram? The accelerator pump diaphram should also be changed. Also, did they adjust the float?

I would add some carb cleaner to the next few fillups to help clean the fuel system. Change out the fuel filter(s) and the fuel line from the tank to the carb. If it has a VOES, change out that hose too. And if the valve on the tank discharge is a vacuum one, change out that hose.

If the engine is spitting fuel out of the carb, there is a reason that pressure is blowing OUT of the carb. I would suspect an intake valve is hanging a bit allowing pressure back through the carb. There are a number of causes for that which should be investigated starting with a compression test to see if one of the cylinders is significantly lower than the other. May have to do this a couple of time with engine "cold" and at operating temp.

Let us know what you find.

Cheers,

TQ
 
Agree with TQ and would add doing a leak down test on the cylinders, you may not see anything out of normal if a intake valve is sticking sometimes, but compression is getting past a intake valve in order to push fuel out onto your leg, could also be a timing issue, if some how it becomes too far advanced.
 
I would also check the float level and the needle valve. You could have some crude in the seat. Or the needle valve could be on the way out. I had carbs spit when the bowl level is too high. Run some seafoam with your gas.

I would double check the intake seals. Changing them is a quick job. As sais by joel, the timing may be off.

It sounds like your dealer may have been more interested in the dyno work then actually troubleshooting the issue.
 
Are you running an air filter and cover? If so, it seems like it would be dripping gas when you stop, and not just blowing on your leg.
 
The bike sat inn another dealership inside on the floor for over 2 years that dealership was trying to sell the bike for him asking way too much my friend asked if i could help i sent many people to see the bike all of them saying Too much money for the miles.. Then the bike was then givin to me by my friend he wanted the bike out of there... I had it towed to a different dealership since it wasnt running any more the 2nd dealer said something was put inn the tanks looked like coffee grinds they cleaned out the tanks I believe took apart an cleaned the carb an replaced intake seals replace all fluids adjusted the clutch an carb i was able to go there an ride it home it ran great.. still smelled of gas then it started spitting got a little worse took it back asked them about it they took it inn did the rejetting dyno thing said it was good to go .. I do rump on this thing i kid you not when my old lady is on i ride like a grand pa lol does anyone know of a good mechanic in the pocono area of Pa.. Next season would like to have this corrected I run a truck an only have so much time to do anything.. So when i can I get on an Ride been off a bike for over 20 years .. thanks for the Feed back got the heater on in the garage gonna look at it today a little i did run some seafoam in it been putting enthenol conditioner inn the tanks an ran some carb cleaner in the tanks every now an then.. was told the Evo motor is a really good motor take care of it itll take care of you.. some one told me put an s&s carb on it but if this one is ok ill do what ever i need to.. id love to have a 6 speed put on next season.. Thank you...

Breeze3at said:
Are you running an air filter and cover? If so, it seems like it would be dripping gas when you stop, and not just blowing on your leg.
Click to expand...
it has A K&N open filter it doesnt drip it hicups an spits only once in a while low rpm high rpm
 
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I guess I'm not understanding what the issue may be. You said it spits, just what does that mean? Does that mean it's missing and when it does gas gets blown out thru the carb? But if it is not leaking from the air filter, how did your pant leg get covered with gas? Is the "spit" part of the hesitation? Is it repeatable at the same RPM? Does it do it under load, decelerating, or steady throttle? Or is it totally random? Could it be the carb leaking?

What is the condition of your plugs? Are the black, oily, or normal?

Kinda hard to troubleshoot without seeing it, or having a common definition of what's happening. Either way, the carb and the intake manifold need to be gone thru again, just to make sure it's right. They are easy to work on, a good HD manual will help.
 
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