Sunday ride bummer

Energy One
Went riding Sunday. Was up in a remote spot in Illinois and the dreaded happened. The Bigdog sounded terrible and lost power until it stopped. It started it but could barely keep it running. Black smoke was coming out the aft cylinder none out of the front. Took the front spark plug out and it was as clean as could be but also dry and COLD. Aft plug was hot, black and sutted up. I Checked and was getting spark in the forward cold cylinder. Started again and put my hand over exhaust and cold air was coming out the forward cylinder and hot black smoke out the aft.

Trailered it home and taking it to Bigdog St.Louis today.

Searched several places under motors and carburators forum and couldn't find any previous links.

Suggestions of what it may be? I'm guessing stuck fuel intake valve or something screwy on the fuel injection. BTW it's a 2007 Bulldog with 1700 miles on it.

I hate it when that happens.

Thanks,

Scott:bang:
 

BadBrad

2005 Pitbull
I'm not that familiar with the EFI but I would think you could do a compression check on it and if the valve is stuck open, that would tell you. You could also blow air into the spark plug hole and hear it coming out the manifold. One more thing. If it's stuck open, you may be looking at piston damage. Did you hear any knocking?
 
Well I took it in and they are looking at it now. Guess I'll wait and see what they think.

I was thinking the fuel valve was stuck closed because the plug was dry and clean. I should have remembered to blow air through and see where it goes. There was not any real pinning or noise
 
Happy Wednesday

:) Well good news. It's usually never this simple but it was the valve guide. The lock nut simply came loose and allowed the set screw to back off and essentially shorten. As a result the fuel valve was not being pushed up and therefore not allowing fuel into the cylinder.

$150 plus they fixed my other shifting problem I was having. After I replaced the Heim joints and greased the shift control, it still didn't down shift. They found that the arm coming out of the transmission was loose, backed off the spline and was hanging up on the housing.

St. Louis BD did great and I'm happy once again :cheers:
 

BadBrad

2005 Pitbull
Glad to hear it wasn't anything major. So, when you tell your buddies what happened, be sure you say the "pushrod" locking nut backed off because you may get some funny looks if you tell them the "valve guide" locking nut backed off.
 

bruce

Active Member
hell thats great news always sad to hear a dog in down, and from what you explained sounds bad.
 

1BADK9

Limited Edition Member
Yeah good news there Scott. I make cleaning and wipng down the bike a reglular inspection time too. Our bikes are notorious for rattling shit loose. Pulled the seat the other day and the postive battery terminal was loose. Mirrors have come loose before, had the starter wire came off the terminal one time too. Although a loose valve guide lock nut isn't something you'd see unless you had the thing apart. Glad to hear you got a quick inexpensive fix. RIDE RIDE RIDE till something else falls off! :2thumbs:
 
:up:Thanks, Yeah I am tighting stuff all the time already went thru a couple tubes of lock tight. I love the way it shakes though. Guess I'll go ride now!
 

Ray

Well-Known Member
Glad to hear you got it going again , and especially not costing you a small fortune. I am taking mine out this afternoon for a test ride to absolutely make sure everything I did to it this AM fixed my little issue.

Ray
 

BigDogBro1

Made in the USA
:) Well good news. It's usually never this simple but it was the valve guide. The lock nut simply came loose and allowed the set screw to back off and essentially shorten. As a result the fuel valve was not being pushed up and therefore not allowing fuel into the cylinder.

$150 plus they fixed my other shifting problem I was having. After I replaced the Heim joints and greased the shift control, it still didn't down shift. They found that the arm coming out of the transmission was loose, backed off the spline and was hanging up on the housing.

St. Louis BD did great and I'm happy once again :cheers:
"VALVE GUIDE....LOCK NUT" ? Are you talking about a cylinder head valve, valve guide and push rod lock nut or what exactly.

"FUEL VALVE"? Are you talking about the cylinder head intake valve?

If you are I can understand how that would cause the problem, except fot the "VALVE GUIDE" part..

Glad to hear it's running! Enjoy the ride......
 
I meant "push rod". I screwed up on the first discription as corrected by Brad (Thank you).

There is an adjustment nut and a nut that tightens against it locking the push rod at a certain height. Both loosened up, and caused it to shorten enough to not push the valve up to allow fuel in the cylinder. The rod is adjustable by removing the "covers?" accessable out side the right portion of the engine.

I'm not an expert but I think I explained it correctly this time.
 
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