79 Invader 340 First time out this season failure

[gixxer6]

I believe Jim was referring to the primer hose not the choke cable. 

[IraqvetUSMC]

Which one is the primer hose and Jim mentioned the plunger which the choke has a plunger so now I'm confused lol.

[IraqvetUSMC]

Ok so primer hose is the two small hoses that  go towards the top of the carbs I am assuming but since they are tied together how would removing 1 line from the carb help and not cause an issue with the other carb or could I eliminate the prime hose from both carbs and cap it off at the fuel pump?

[Interceptor398]

The primer if hooked up correctly will have a T in the line by the fuel pump that goes up to the primer.  From there it goes from the primer to a T in the line that runs between the carbs.  In the past I have cut the line just before the T in the line that runs between the carbs and put a pin in the line to plug it both ways.  I used a busted drill bit that fit the line ID and put both cut ends of the line on the pin. Everything was still in tack but the line did not allow anything to move in it.  Before you do this if you can, when the sled is running watch for any sign of gas or air moving in the lines and the plunger leaking gas around the shaft.

[IraqvetUSMC]

Thanks interceptor. That sounds like a good clean way to go about it. When the sled is running I can see gas and air bubbles mixed in running through the small lines going to the carbs, not sure if it's supposed to do that or not. But I believe only the one carb on the right is the one flooding out because of the amount of fuel that has blown past the exhaust flange mounted on the right cylinder causing fuel to spray onto the front of the cylinder. Is the "plunger" the push/pull lever next to the key switch? If so I have not noticed a fuel leak there but i haven't removed it to see in there to tell if it is.

[gixxer6]

Another way is to simply connect the two small fittings on the carbs together with a piece of hose. 

Yes, the primer is the plunger next to the key.  Just because you don't see fuel leaking here doesn't mean the primer isn't bad.  There is a check valve that is inside the primer that goes bad.  This check valve is designed to only let fuel pass when you operate the plunger.  When it fails (which seems to happen a lot) the vacuum created by the engine sucks extra fuel through the primer.  This creates a rich condition. 

[IraqvetUSMC]

Gotcha, I do know the primer works as
I can see fuel and air bubbles when I push it and it's pushing fuel to the carbs. What I also found is that I have a fuel leak at the T by the fuel pump that the small primer hose ties into. If that were the case I would think that letting air in the primer system would lean it out more but I could be wrong but then again I could have 2 issues, a bad plunger and the line just happens to leak fuel at the T.

[Interceptor398]

Just putting one line between the carbs can still cause problems if you don't plug the line down by the fuel pump.

[IraqvetUSMC]

So realistically I could remove the T by the fuel pump and then make a
Jumper between the carbs with 1 line? If I can see fuel and air bubbles running through the primer hose while the sled is running I am under the assumption that's not good and the fuel is just bypassing the plunger and the air bubbles are probably from my fuel leak down at the T by the fuel pump.

[IraqvetUSMC]

Are these Primers really needed or will the sled work just fine with eliminating them from the system.

[Interceptor398]

So realistically I could remove the T by the fuel pump and then make a jumper between the carbs with 1 line?  Yes

The primer is not really needed unless it is very cold out or the sled has sat for a long time.  I have a few sleds that the primer lines are plugged as I describe earlier.   If you are not aware of the problems a bad primer can cause it can make you crazy trying to find out why your sled runs like crap.

[IraqvetUSMC]

Well I think I just found my issue that started last winter. I think the plunger was froze up and not allowing the fuel to go by and the sled was running fine on the ice at 3/4 to full throttle
For almost an hour until I climbed a huge hill and bogged it down and it died out on me. I'm assuming while climbing that hill the carbs loaded up and the self hadn't ran rite since. I did find the float bowl plug moose and leaking so I resealed the float bowel and plug and the sled starts and runs fine at half to full throttle but will only ideal for a couple minutes until it loads up and dies and then fuel comes out of the exhaust pipe making a nice puddle on the floor.

[rminier]

 Actually, if your sled idles OK for a couple minutes, then loads up and slows down, you're really close.
Everything has to be set just perfectly for these sleds to idle perfectly for an extended period of time. Usually you have to blip the throttle every so often when the RPMs start to drop.
 I hate to say it, but a leaking crank seal can cause the symptoms you're describing, also.

71 degrees in Delphi, Indiana as I type this....unreal. I guess I might as well get the sleds put away for the summer.

[IraqvetUSMC]

I know crank seals are a must and I will eventually get around to it. The sled will start on 1-2 pulls and idle for a little bit but will eventually load up and die unless I suspended the track and run it at wot and then she runs great. I did notice when I had the sled suspended off the ground I had the hood open and I seen fuel going through the primer hoses into the carbs, i know that when the plunger is pushed in their should be no fuel going to the carbs which I didn't know that before. So I bet if I eliminate the primer system the whole flooding issue will go away. Also I would think a bad crank seal would allow air in the engine and lean it out vs flooding it out. And yes i live right up the road from you rminier and it was rather nice today wasn't it haha.

[rminier]

 Yep, I would try plugging those primer hoses and see how it acts.
 Bad crank seals allow air to leak into the engine, but they can also cause some other crazy problems.

 Oh well, we may as well get ready to sharpen the mower blades now...