Yerf Dog help.

[dc3coyote]

We were given a YERF dog, from the guy who runs the gym here on base.
The problem is, it wont run, the engine is backfiring and not even starting.
I think it may be a choke problem, the choke was seized, and in the process of trying to loosed the handle loose the wire broke. This was good news to me, because now I can at least move the choke back and forth. The problem is its still back firing and not starting.
If you have any ideas, I would greatley appreciate them since I am now just banging me head against the wall doing nothing.

I tried to download the file and it keeps freezing in process, my internet here sucks.
Heres a link.
Yerf-Dog Owner Manuals
The model is one of the camo models

 

[LanceRobson]

What's a Yerf-Dog? A pug with a speech impediment?

Lance

 

[doghead]

If you think the choke was an issue and it has been choked, maybe the sparkplug is fouled with fuel or carbon and needs to be replaced.

 

[Lifer]

I'm assuming that you've already done the usual tests for fuel, compression and spark. The first thing you need to do now is to determine what engine you have. Briggs & Stratton, Clinton, McCulloch, Honda, Yamaha, and Kawasaki are the most common for that kind of application. Once you figure that out, get a factory service/repair manual for it. You'll never regret it.

 

[WillWagner]

DH is correct. If the choke has been stuck, the plug is most likely fouled. Slam a new one in there. If it has been sitting, the gas nowadays doesn't have any shelf life. You'll probably need to pull the float bowl at a minimum and clean it out.

 

[Recovry4x4]

My Yerf Dog was doing the same thing, backfiring all over the house. I tried choking it but had the same results. I switched him to Hill's Science Diet and he has been running regular since. Love the Science Diet.

 

[dc3coyote]

Thanks, I am going to pull the Carb out tonight, after my last inspection.
The army does not make things simple as far as getting parts or tools right now. Every time I go somewhere I am told that everything is allready being shipped out. I am having to get extremley creative for fixing things around here.

Lance a Yerf Dog, is a cheap version of a Mule, its just a side by side cart.

 

[phil2968]

Honda engine most likely, fouled plug in a Honda will backfire all day and never start. Replace the plug. Cleaning the carb should include pulling the main jet AND the emulsion tube/discharge nozzle just above it. Canned carb cleaner all the passage ways paying particular attention to the idle circuit. Wish I was there to help ya!

 

[LanceRobson]

When you pull the plug, if it is crudded up with carbon you may want to pull the head and clean the carbon out the combustion chamber. Not only will it raise the compression ratio (sometimes dramatically) with bad consequences for the rod, bearings etc., the carbon tends to have hot spots which can ignite the incoming fuel/air mixture and cause backfires.

If the plug and carb cleaning don't help and you have overhead valves there is a chance that you have a valve or other compression problem.

A good diagnostic tool is an air hose (as in a compression tester hose) that has a female air hose fitting on one end and threads for the plug hole on the other end. Many of the GI compression testers are set up that way. The gauge goes on the hose after the hose is screwed in to keep the gauge from being beat up. Even the sets for diesel engines usually have fittings for spark plug holes.

If you run the piston to top dead center (TDC) of the compression stroke the valves should be shut tight.

Then screw the air hose into the plug hole and put compressed air on it. If air comes out the carb, you have an intake valve problem. If it comes out the exhaust you have a exhaust valve problem. If more than a tiny, tiny bit comes out of the crankcase you have a piston or ring problem.

Don't forget to check all the fasteners, gaskets and seals in the intake side of the engine. Leaks in any of them can cause mixture problems.

Lance

EDIT: I have generic shop manuals for most bigger air cooled engines and a bunch of make and model specific ones. Post up the engine info and if I can find the manual I'll see if I can scan it and email it to you.

 

[onegmjack]

If it has a GY-6 engine,it mite be choke-less.It uses a fuel enrichment valve.If you go to thier site in England,they are some trouble shooting tips.good luck.Mine only starts when the sun shines.When it's 60 degrees it want hit at all.I am going to try a coil when I feel like I want some fun.