Gas running out of yerfdog 150cc exhaust

Ask for help getting your buggy running. Only post here if you have specific questions about a problem you're having.

Moderators: Buggy Depot, PGH

Gas running out of yerfdog 150cc exhaust

Postby yerfDogFromHell on Sun Sep 29, 2013 3:41 pm


We are having trouble getting our Howhit engine to run correctly. It usually starts fine but will only run well at idle. When we run it around it only runs for a few minutes and then stalls. When it's shut down we noticed the a strong smell of gas. We saw gas trickling or running down the exhaust manifold. If we just let it sit without running the engine and leave fuel cut off on we don't notice gas coming out of the carburetor overflow outlet. If the float wasn't adjusted correctly I would have expect gas to flow out even when the engine was stopped. The very last time we ran it we noticed a little white smoke coming from the head.

This Yerfdog does not have the standard air box. It has a performance intake tube. This is how it was when be bought it. Right now there is no line fuel filter. Is does like to start or run with the fuel filter inline. We've cleaned out the gas tank and filled with new gas. We've also replaced the spark plug.

We purchased a spiderbox 150cc last fall. It initially ran but was running sporadically. After 30 minutes of running the engine would be down on power and would eventually stall. Also it was hard to get the engine to start. We noticed the carb would leak fuel after shut down. We adjusted the carb float to fix that issue. We were going to rebuild the card but when I opened it up it looked virtually new. I'm guess the carb had been replaced. There was also upgraded CDI and coil.

Eventually the starter failed. We noticed the exhaust was barely hanging on and some of the wiring connects were just twisted together. Spent the better part of this summer replacing or repair the wiring harness. The electrical side now seems all set. Replaced the starter and start and kill switches and associated wiring. Went thru all the loose connections and solder and shrink wrapped them.

This has been a nice father/son project. We've spent many many hours working on this and would just like to getting running consistently.

Thanks for any help of advise.
Posts: 1
Joined: Tue Aug 28, 2012 11:53 pm

Re: Gas running out of yerfdog 150cc exhaust

Postby PGH on Mon Sep 30, 2013 11:19 pm

If fuel is flowing out of the carburetor or exhaust, your float is not properly adjusted or the float valve is not sealing.

If it starves for fuel after running it hard, you may be getting a vacuum lock on fuel flow due to a blocked gas cap vent. This would also explain why you have flow issues when using a fuel filter.

Once you have the fuel issue fixed you will need to change the oil because I'm certain tha gasoline got past the rings and is mixing with oil. Run the buggy for half an hour on the changed oil and then change it once more to ensure you are running oil that is not contaminated.
2006 Tank Urban Touring 150SE
6" intake plenum, 1.5" UNI filter, K&N precharger, 130 main jet, NGK Iridium IX CR7HIX spark plug, MRP yellow adjustable CDI, Orange high output coil, 14Ah sealed battery, 2000 RPM red torque spring, Koso 115mm variator, Dr Pulley 12g sliders
User avatar
BD-ORB Moderator
Posts: 2398
Joined: Wed Aug 02, 2006 10:38 pm
Location: Pacific NW

Return to Got Problems? Ask for help!

Who is online

Users browsing this forum: No registered users and 4 guests