So I have an 03 dyna Low Rider and noticed a burp type hiccup From the carb when riding. This only happens when cruising at slow speed or first acceleration through gears after a stop. At first I figured it was an air/fuel mixture issue so I changed the plugs and leaned out the mixture, but the hiccup got worse so I put it back to the 2 full turns out. I tried spraying carb cleaner around the manifold and noticed on the rear gasket there was a slight increase in idle, but nothing from the front. After telling a friend about this they suggested that it was more of a vacuum leak probably from the vacuum line from petcock to carb rather than intake gasket due to the engine revving higher than sputtering down. Any suggestions on what I should to to correct this issue?

 

Change your intake manifold seals. Vacuum line to petcock only open to flow the gas with the engine running.

 

There are so many conditions that can cause what you're describing.

 

Well, I guess if it continues after I replace my intake gaskets Ill need advice on where to look and what to fix next. Hopefully you and TexasScooterTrash can point me in the right direction

 

Same issue... Curious for more information

 

question before I do it??

as I slept on it the thing a local dealer told me to do just doesn't sound right??

they told me I can use windex and spray on the intake manifold and exhaust manifolds to determine if there's a leak?? smoke or not?

 

I just got the gaskets in the mail yesterday so just need the time to take everything apart. Im not too sure about using windex or an ammonia based liquids. Personally it doesnt sound right and I dont want to introduce anything into my engine like that. Ill stick with carb/throttle body cleaner, or propane. At least I know for a fact none of those will harm the engine.

 

DT …hope that works! just went to get carb cleaner. going to hit the intake and exhaust ports.


well good news for me that it has to be a slow jet... now just have to figure out what is in the carb?? re worked carb so will have to tear down!

 

check and see if your petcock is weeping gas. Those things are notoriously awful. If I were to get another carbed twin cam swapping to a manual petcock would be one of the first things I’d do.

 

The windex will probably smoke and burn, but the only thing that's diagnostic of is the fact that those things are hot. Buddy must've been thinking of tire leaks, but even then windex doesn't really have enough sudsy stuff to work well for that. It sorta works.

I don't think it would hurt much but I wouldn't be spraying a bunch of soap around there. Soap that doesn't get rinsed off leaves behind sticky soap concentrate that just attracts more dirt and contaminants.

There is an aerosol spray made to help start engines, forget the name but that would be ideal. Next would be to waft propane from a small torch at it. Safer and no residue but hard to get a positive result because it really has to be wafted in there, whereas the sprays can sorta be pushed into the test location.