akrievins
New member
Just a question for all of you out there...
Luckily this is not my Viper I'm talking about here.
A buddy just bought a 1999 Ski-Doo Formula 500 as his first sled. It was running fine for him, but last weekend he had it running for 15 minutes to "burn off the gunk". He shut it off, and has never been able to start it since. I'm going up to his place to take a look at it this weekend.
He said it has spark... checked by putting the plug on the engine block.
Wasn't much gas in the tank, but should have been enough to start it.
The thing that gets me... he tried pouring a bit of gas down the jugs and it still didn't fire.. even for a second or two.
Any ideas???
Luckily this is not my Viper I'm talking about here.
A buddy just bought a 1999 Ski-Doo Formula 500 as his first sled. It was running fine for him, but last weekend he had it running for 15 minutes to "burn off the gunk". He shut it off, and has never been able to start it since. I'm going up to his place to take a look at it this weekend.
He said it has spark... checked by putting the plug on the engine block.
Wasn't much gas in the tank, but should have been enough to start it.
The thing that gets me... he tried pouring a bit of gas down the jugs and it still didn't fire.. even for a second or two.
Any ideas???
I would guess it is simply not getting fuel. It is easy to put too much fuel down the plug. I would try starting fluid instead of raw fuel. The liquid doesn't ignite - only the vapor ignites.
If no go with starting fluid, then I would test the electric system starting with the plug caps.
If no go with starting fluid, then I would test the electric system starting with the plug caps.
ViperTom
New member
Fouled plugs?
Change the plugs and give it a try.
Change the plugs and give it a try.
Check the compression. I left a ski-doo idling last year and overheated it. The ring melted to the piston, loosing all compression in one cylinder.
yamyrider
Active member
all good places to start as suggested in the above posts...compression, fuel, crank seals....are both plugs firing. Let us know what you find
akrievins
New member
We will check these things during the weekend. I'll post the results.
mopar1rules
Active member
Ding said:
well it turn in a kind of vapor went its mix with air but gaz direct in cylinder should ignite....
mopar1rules
Active member
modsrx said:
yep...it will. done it many times before.
Without getting technical, when you pour gas down a spark plug hole and try to start it, some ends up in the crankcase where it has a chance to turn to vapor and be pushed into the combustion chamber where it can ignite. However, much of it is wasted and ends up in the exhaust pipe. Ever blown a pipe off when it pools in the exhaust long enough to vaporize and then ignite?
Yes, some of the poured gas turns to vapor and that is what ignites, but what I was pointing out is that too much gas can easily flood the engine and cause the plugs to short out and not provide spark. If one remembers that only the vapor actually burns it helps to avoid pouring a lot of gas down the hole.
Also, when temps drop very low it is very difficult to get fuel to vaporize.
Yes, some of the poured gas turns to vapor and that is what ignites, but what I was pointing out is that too much gas can easily flood the engine and cause the plugs to short out and not provide spark. If one remembers that only the vapor actually burns it helps to avoid pouring a lot of gas down the hole.
Also, when temps drop very low it is very difficult to get fuel to vaporize.
akrievins
New member
Well, back from the weekend and we got his sled started. The throttle needed to be held a bit open while pulling. After that it would run and idle fine, but in order to get it started from cold or warm, it needed the throtle to be pressed about 1/4 of the way.
Nature of the beast, or is there something to fix/adjust?
Nature of the beast, or is there something to fix/adjust?
Just curious... does the sled have a primer for starting? If it does, my buddies('95?) 580MXZ starting process goes like this... 1 prime the motor(lots of fuel!) 2 hold throttle 1/2 open and start pullin! hot or cold doesn't matter-same ritual-nature of the beast?
onewickedr1
Member
nature of the beast
i have a 99 mxz500. prime 5-10 times and pull w/an 1/8 to a 1/4 of throttle. mine starts on 1st or 2nd pull.
i have a 99 mxz500. prime 5-10 times and pull w/an 1/8 to a 1/4 of throttle. mine starts on 1st or 2nd pull.
Primer may be shot if it has one.
akrievins
New member
Yeah, has the primer. We used that about 5 times... maybe it needs 10 like like was mentioned above. Could be broken as well... who knows.
Well, it looks like most people with similar sleds have to do this as well.
Thanks for all the help everyone. Who knew Doo's could be so fussy... That's why I ride Yamaha!
Well, it looks like most people with similar sleds have to do this as well.
Thanks for all the help everyone. Who knew Doo's could be so fussy... That's why I ride Yamaha!
On my Ski doo's they take around 4 or 5 prime pumps to start. It can take a few extra pumps sometimes to begin moving fuel. You can feel the resistance in the primer once the fuel starts moving. Count 4 or 5 pumps from there. Once it is running it helps sometimes to lightly give it shots of gas with the primer to keep it going. I do not hold the throttle open while starting with this process.