Paradise lost....

[Viktory2k1]

Hello.
I posted some details on the general talk board but I think I should post here instead.
This snowmobile was purchased by my Father brand new in 77. I just got it about 2 months ago and went through it so to speak. Had it running great even with the bad gas that was in it, not old but very oil rich. My Father passed away Dec 21st. After trying to recoup, I got 6 gals of fresh gas and oil and filled it up. This is Sat the 29th. Fired it up and rode around the yard for maybe an hour. Ran great.
The Sunday, maybe an hour before the Packers Vs. Vikings game, I wanted to cruise around. It would not start. I even tried ether, nothing. All it would do is fire about every 5 pulls. I pulled it into the garage by hand(still sore)and fired up my heater. Left it alone for about 45min. Then I decided to clean the primary coil terminals. Broke the left one off so put an alligator clip on to hold terminal to wire for now. Didn't mess with the right one. No mater what I did, the best it would do is just fire once in every 5 pulls or so. Tried 3 sets of plugs, checked for water in fuel, checked fuel pump just by removing fuel line from carb and pulling 3 times, works good. Spark always looks good. Plugs always wet with fuel/ether. A few pulls it wanted to pull starter out of my hands which it has never done before.
I dragged it back into the yard and called it a night.
Today I decide to try again. Same thing and everything I check seems good. At this point I am wondering if someone pissed in the gas tank but I checked that.
I did notice one thing not good.(besides being super flooded)
I pulled the plugs to check spark(again) and every so often I would see a faint orange spark on the right coil. Plug still bright blue.
The spark seems to come from the primary terminal to the aluminum bracket the coils mount to. I mean like 3/8 to 1/2"long spark. I split a piece of 3/8 fuel line and put on edge of bracket but spark just went to the left.
If this msg makes sense to anyone, please respond.
I just don't understand why a primary wire would make a spark like that. Or maybe there is a voltage leak from the secondary side looking like its coming from the primary terminal? Cant think straight, long week last week.
I don't even know if this has anything to do with it not running all of a sudden but its the only unusual thing I found so far.
Vic

[harleysportster]

Sounds like you have mulitple problems with a weak spark and flooding at the same time.
Weak spark- clean all the grounds for both coils on the aluminum plate. The plate itself should have a ground strap bolted to it and the side of the engine.
flooding- check float/ needle & seat, replace if needed.
Pull plugs, turn off key and pull recoil over to help dry out the crankcase. Close off the impulse line with a clamp or thin vise grips. Try and start engine. If the engine starts, shut it off and then open impluse and try again. If the engine floods, the diaphram has a hole in it, letting fuel directly into the crankcase.

[lwb140]

i have a 78 liquifire that has a bad coil wire on a coil.once in a while spark will jump from the coil straight to the block and it will miss . sounds like something similar to what you are talking about , i tend to agree with harley though , sounds like you have more than one issue at hand , where in wi. are you in ? wade

[Viktory2k1]

Wade,
I Live in Muskego, A small city in Waukesha Co.
I will check all ignition grounds with an ohm meter before messing with any bolts. As far as a ground strap, there are 2 ground wires on a bolt on the right side of CDI box, thats right, one or both go to a bolt on fan shroud. So I guess the coils ground through bolts directly to the aluminum plate and that grounds to engine. I spoke to my brother earlier and told him this(he had in the early 90s)and he said it would not run when he sold it with the same symtoms. He said the new owner replaced the CDI box and all was good. I then got ahold of the new owner and he said it ran great from day one and never had a problem.
I dont know who to believe.
I do not have the best understanding of how CDI boxes work but they get a signal from the coil and make a spark at the exact right time. They work or they dont right? I just dont think its the cdi box with a bright blue loud spark at plug. The carb is like new inside. I think I will check the fuel pump carefully. Maybe that would explain the running great one day, to not starting and flooding the next day with fuel dripping out where exhaust manifold meets muffler. It does fire though. It will be warmer here tomorrow so I can work on it for more then 10 minutes.
single digits now
Vic

[Viktory2k1]

Forgot to mention, the fuel pump does pump very good.

[lwb140]

thanks for the update , it sounds like it is something pretty simple , if it will fire try holding the throttle open while pulling the rope over to help clear the flooding , you might try a fresh set of plugs too , keep us posted wade

[Viktory2k1]

I just wrote a huge msg but it didnt work I guess.
To sum it up: all ign grounds good, coil resistance is low 200s
fuel pump good, no fuel contamination. ran for 2 seconds.
I just dont believe its cdi box spark is bright and loud at plugs. Maybe timing is screwed up from cdi box?
Stator ring was tight when I had motor apart, along with coils.
I did find a bad spring-clamp on a fuel line. replaced line and both clamps. NOTHING.
I used to consider myself a small engine expert but not any more...
I WILL figure this thing out.
Its the one thing I haven't checked yet(or overlooked)
Man, I wish that last msg I made posted..

[Viktory2k1]

Oh yeah. This thing wants surface-gap plugs for some reason.

[lwb140]

what about surface gap plugs ? i run br9es ngks or equivelent , i agree , if youve got good strong spark its hard to think its ignition related . id strongly consider replacing the plugs if you havent already, seems like once they get good and fouled they are just toast , that leaves compession and fuel , i am forced to believe since it ran well at first it has compression 130 lbs or so on each side past that we are back at fuel wade

[HoosierDeereMan]

Wade is right. Spark plugs will only take a fuel fouling so many times before they are shot. It's been my experience that it takes a really strong CDI box to fire and run surface gap plugs. Some CDI units will fire them fine while others will not, but will fire a regular electrode style plug perfect. For just everyday general riding I'd use the regular electrode style plugs. From what you are describing it sounds like you are flooding the engine. When you put new gas in it did you mix it 50:1? It sounds like maybe the new gas has cut some of the old crud loose inside the carb maybe? Does this have a Mikuni carb? Is the face of the choke plunger nice and flat or does it have a bad seating groove in it. If the choke plunger isn't seating or adjusted correctly it's just like you have it choked and will be dumping added gas in the carb each time you yank the rope. The choke plungers are replacable. Are the floats in the carb set right? With the fuel bowl removed and the carb upside down is the float arm level? If not adjust the tab that contacts the needle and seat until it is level. Do you have a viton tipped needle for the needle and seat? If so, I would replace it with a regular metal faced needle. The viton tips will leak. Just some ideas to think about.

Troy

[HoosierDeereMan]

Another thing you might check is the air box. If there is a mouse nest in there it will cut off the air to the engine. The plugs will be wet and the engine will hit but not run or run on one cylinder a few times and then die. Don't ask me how I know this!

Troy

[Viktory2k1]

OK.
Pulled muffler and checked it, nothing pluging it, reinstalled. Took airbox off and it looks good. I did notice carb(MIC VM-34)mount flange seemed odd like it maybe has a split so pulled that off. Nothing all the way through at my first inspection. Carb has the steel needle/seat. I didn't disassemble carb since this happened but totally went through it a month or so ago. Floats perfect along with the rest of it. I also do not think bad reed valves can cause this.
Hoosierdeereman pretty much knows exactly what its doing. It will fire maybe every 5 pulls or so. This never changes no matter what I do. It had brand new BR9ES plugs in it and I put another set in it and no change. I even tried just B9ES with the same results. Now the fray in recoil rope is starting to get worse. This must mean that there is a huge blizzard on the way.
The manual calls for a champion QN-1 surface gap plug but they don't make those any more and it ran fine on these. Its gotta be something with ignition like the timing is off slightly for some unknown reason. I cant find my compression gauge but a thumb over spark plug hole seems to tell me it's fine. I do not own the dial indicactor to check timing. I even disconnected fuel line from carb and pulled it enough to fill a spray paint can cap half way and dumped it on ground and set it on fire just to see if it burns, it did.
I disconnected the key and emergency switches just to see if there was an intermitant short but no luck. I will use an ohm meter tomorrow on these harnesses and do a wiggle test. I also checked for different footprints around the sled to see if someone sabatouged it, none. I've dealt with many mouse issues on my sled, even this one but no sign of any now. I just know it ran great last time I rode it and next day, nothing.
Later.............

[lwb140]

Well, I'm not sure at this point what to tell you , exept this , I'm 2 hours south of Chicago just off of I 65 I have 2 77 340s that are riders , extra cdis , an extra Hewtech setup , carbs fuel pumps plugs coils etc , haul it down here and we will make it run , we can swap parts etc , can bolt on an electric starter till we get it figured out I'm available Saturday. Wade

[Viktory2k1]

Thanks Wade.
A few problems:
I do not have a trailer .
I have a slight panic disability that makes it very hard to travel. I may have past your area in 06 to go to the Allstate 400 at the Indy motor speedway. Do you think a CD box is causing this?
I have many tools here. I lost my job so have more time then money. I live about 13 miles west of General Mitchell Int'l airport. Maybe you be in this town soon?

[lwb140]

im 45 minutes west of the indy 500 track , personally i think your cdi is fine , like troy said [hoosier deere man ] says sounds like youve got a rich flooding over ploblem , maybe a cdi too , but that is quick and easy to swap out to check , your motor will have a starter ring gear on it , ive never resorted to it but an electric starter will make less exhausting work out of spinning it over , i wont be up in your area very soon , offer stands if you can get down here, warm shop, a little snow , btw back to basics has your motor had crank seals rescently ?, shouldnt really keep it from running but will cause all kinds of runability issues as well as lean-ness and catastrophic burndowns ,wade