Can't start my Sled - Snowmobile Forum: Your #1 Snowmobile Forum

ptrapper65 · 08-03-2008, 06:19 PM

AC panther... I have a spark and it kicked over on the first crank, but I couldn't keep it running. On my next try, it just cranked. After the first try, it doesn't "kick" again. I like to run it every month during the summers, but this time it wouldn't start. Could it be the gas??? I did put stabilized in it last month. Any suggestions???

Also, what is the best way start these 2 stroke engines? I have bad luck with any of them from my sled to my chain saw. Is there a trick??

Thanks Fellas

lrnnorth · 08-04-2008, 05:04 AM

Right now its really warm so the jetting is going to be WAY too rich. Its going to want to flood it out so your prolly going to have to hold the throttle quite a bit.

**RJ Gleason** · 08-04-2008, 08:02 AM

Put the track up off the floor and hold the throttle wide open until it starts.

ptrapper65 · 08-05-2008, 07:08 PM

Quote:

Originally Posted by RJ Gleason

Put the track up off the floor and hold the throttle wide open until it starts.

Could I just remove the drive belt and do the same??? That is without lifting the track.

brown435 · 08-05-2008, 07:44 PM

Quote:

Originally Posted by ptrapper65

Could I just remove the drive belt and do the same??? That is without lifting the track.

You could but might over rev the engine and cause damage.

You could lift the back end with an engine hoist?

**smallengineguy** · 08-06-2008, 06:06 AM

Change the fouled spark plugs, then lift the back of it. Or, wait until next month when it starts to cool down a bit.

ptrapper65 · 08-06-2008, 06:33 AM

Quote:

Originally Posted by brown435

You could but might over rev the engine and cause damage.

You could lift the back end with an engine hoist?

Yes, I could lift the back. I usally do it with a 2x4. I just don't like when the track is spinning off the ground. All I can think of is it slipping off the support and the sled taking off into the wall.

ptrapper65 · 08-06-2008, 06:34 AM

Quote:

Originally Posted by smallengineguy

Change the fouled spark plugs, then lift the back of it. Or, wait until next month when it starts to cool down a bit.

I think that's what I'll do. The plugs look pretty good though.

**RJ Gleason** · 08-06-2008, 08:56 AM

Put a square piece on the bottom end and a notch in the top end and you have a cheap stand that will not fall over.

**BC_Dan** · 08-07-2008, 09:15 AM

Like RJ said.

It's not a safe practice to rev the engine without a belt in the clutch, the force will slam the clutch sheaves together, possibly resulting in catastrophic failure. The resulting parts and pieces can penetrate shrouds and guards and cause a lot of problems.

The biggest "secrets" to easy-starting 2-strokes are clean carbs, good gas, and appropriate jetting/carb settings. Even if the carb is jetted too rich for this time of year, the sled should still at least start easily. Too rich may not allow you to even move the sled, but at idle it should still run. Check the pilot jet and the air and fuel passages to the pilot jet, you may have some gunk that is interfering with proper operation...

ptrapper65 · 08-07-2008, 05:52 PM

Thanks BC!! I always have trouble starting 2 stroke engines. Can you reply with the way you do it, like if the choke it on, don't give it gas (I read this in the manual, but I always give it gas). What I need is a dummies guide to starting my sled like pump throttle twice, give it full coke, crank.

**BC_Dan** · 08-08-2008, 12:17 AM

On a Mikuni carb, there really isn't a "choke". What there is instead is an enrichment circuit. The circuit adds fuel when you flip the lever. The amount of fuel being delivered is dependant on the velocity of the airflow across the opening in the carb. When you give it the gas when trying to start, the throttle lever lifts the slide, making the area where the volume of air is flowing a lot greater. Because the area is greater for the same amount of air, there is a lot less air velocity across the enrichment circuit opening and the amount of fuel being added is not great. Keeping the slide on the bottom (hands off the throttle) maximizes the velocity of the air and creates the greatest amount of fuel being delivered.

These carbs also have three main parts; the pilot jet, the needle jet/jet needle, and the main jet. When the engine is at idle to about 1/8 throttle, the pilot jet is delivering fuel. At 1/8 to about 3/4 throttle, the needle jet/jet needle is metering the fuel (the fuel that the needle jet/jet needle meters comes from the main jet). After 3/4 throttle, the slide lifts the needle so that it no longer is a player in metering fuel, so the main jet is what controls fuel ratio.

That said, if you look at where you are having problems, you can work on that system in the carb. If you have hard starting issues, the enrichment circuit or the pilot jet is where to start looking. It does not take much varnish at all before the air and fuel passages to the pilot jet get clogged, and that jet is VERY small. Disassembling the carb, removing the pilot jet and "flossing" it with a small wire (I use one strand of telephone wire with the insulation stripped, or sometimes monofilament fishing line). Cleaning the passages with the wire is sometimes helpful. Those jets have to be pretty much spotless to work properly. Aerosol carb cleaner in all the passages helps, just be careful when spraying, sometimes it sprays back at you!

You may also want to make sure the enrichment plungers are not stuck in the carb, if they are not coming up, no additional fuel is delivered when you "choke" the engine.

When I start my carb sled cold, I put the lever on full, hands off the throttle, it starts first or second pull, even in the summer. If it won't continue to run, you know where to look!

And pumping doesn't help, as there are no accelerator pumps at all in sled carbs; all that will do is build up your thumb muscles

**RJ Gleason** · 08-08-2008, 07:58 AM

Good one there Dan, I am going to copy this and add it to the "how to" section, with appropriate credit to you.

ptrapper65 · 08-08-2008, 09:11 AM

Quote:

Originally Posted by RJ Gleason

Good one there Dan, .....

Agreed!!! That's a great explanation. Thanks for your time BC_Dan!! It must have taken you a long time to type all that and I really appreciate it.

clodev · 08-08-2008, 03:38 PM

I'm now that much smarter. Thanks BC Dan

**BC_Dan** · 08-08-2008, 08:15 PM

You're quite welcome. Always glad to help when and if I can

ptrapper65 · 08-18-2008, 07:27 PM

Alright BC_Dan, here is my last question. Would it be worth it to clean the Carbs this weekend and let them sit until the start of season, or should I put it off until say Thanksgiving?

**BC_Dan** · 08-19-2008, 12:09 AM

It definitely helps to get the fuel out of the float bowls if you aren't going to start the engine over the summer. If I fog the engine for the summer, I drain and clean the carbs and leave 'em dry all summer. No varnish can build up if there's no gas to evaporate. If I don't fog the engine, I try to get out and start the sled at least monthly and let it run until the rear heat exchanger heats up. I'm about 50/50 this year, fogged 2, one's in the garage (broke), 2 I start. Gotta have that 2-stroke smoke fix somehow!

I'm sure my neighbors think i'm nuts

If you do drain the carbs, when it's time to get 'em going again, take a syringe and squirt fuel down the vent hoses. That will fill the float bowls a LOT quicker than pulling the rope. I usually use mixed gas to do that, a little extra oil can't hurt first time you start it after the summer...

ptrapper65 · 08-19-2008, 07:58 PM

^^^ Thanks!!! I really appreciate all of your time.

ptrapper65 · 08-28-2008, 09:31 PM

UPDATE: I tried starting the sled again, this time successfully. It’s been a month since not being able to start it so I flipped the choke, turned on the fuel supply, turned the key to on and pulled the chord and on the first pull it started????? Last month when I tried it, I used the electric start. Do you think that has anything to do with why it wouldn’t start last month and it was so easy this month? The temperature has not changed that much.