Starting snowmobile engine in gocart

[ArlyA]

Whenever someone tells me "it ran fine XYZ ago" I automatically assume that stabilizer was not added, the fuel has gone bad and its system will need a clean out. Fuels have done that, long before alcohol was ever being added to them. I've not had good luck cleaning them out by adding a "gum out" type products. In my seasonal engines, like snowblowers, saws and lawn mowers, anything that doesn't get ran on a regular bases, I keep SeaFoam in them at all times. It's much cheaper to do than to have there systems de-gumed.

Good luck and let us know how the repairs goes.

 

[farm boy00]

Whenever someone tells me "it ran fine XYZ ago" I automatically assume that stabilizer was not added, the fuel has gone bad and its system will need a clean out. Fuels have done that, long before alcohol was ever being added to them. I've not had good luck cleaning them out by adding a "gum out" type products. In my seasonal engines, like snowblowers, saws and lawn mowers, anything that doesn't get ran on a regular bases, I keep SeaFoam in them at all times. It's much cheaper to do than to have there systems de-gumed.

Good luck and let us know how the repairs goes.

Talked to him and told me about the seals where I can get them. I thought it was treated cause the mini chopper I got on the same deal has stabilizer and gas was still good. It fired right up with a shot of staying fluid. I put more fuel in it too but the want enough to help out the old stuff.

 

[trhode58]

Fuel, Spark, Air or Compression. Check them all, one by one. I typically go in that order.

 

[Cord]

Just like any engine their is a seal where the crank exits the case. On a normal engine when the seal fails it just leaks a little oil. Annoying, but that's the limit of it. 2 strokes are a bit different. With a 2 stroke, the crank case is under a vacuum. This means when the seal fails, the engine draws air past the seal. This results in a lean condition that results in the engine burning down. The torch trick will work for checking the seal, but typically the seal is hidden behind the mag or clutch so you can't get the torch close enough. How hard is it to replace the seal? Tough. You'll have to fully disassemble the engine to get to them.

 

[Clint S]

Just like any engine their is a seal where the crank exits the case. On a normal engine when the seal fails it just leaks a little oil. Annoying, but that's the limit of it. 2 strokes are a bit different. With a 2 stroke, the crank case is under a vacuum. This means when the seal fails, the engine draws air past the seal. This results in a lean condition that results in the engine burning down. The torch trick will work for checking the seal, but typically the seal is hidden behind the mag or clutch so you can't get the torch close enough. How hard is it to replace the seal? Tough. You'll have to fully disassemble the engine to get to them.

All correct and these engines have a center seal also. When it goes, and these engines are known for it, the base cannot pressurize correctly causing
Issues with intake and exhaust. Symptoms are hard starting and poor running to not running at all.

 

[JRobyn]

"Center seal"? I have a good bit of experience with many different makes of 2-cycle engines, but your terminology is confusing me. I can only imagine how FarmBoy feels. Exactly what are you talking about? The seal between two halves of the crankcase? The seal between the crankcase and the reed valve housing/intake manifold?

I agree that problems with these would cause the symptoms described, but IMHO, not too likely to have spontaneously failed due to just extended layup.

 

[the old grind]

On multi-cyl two strokes there are crankshaft seals between the cylinders that if bad will deny the cyl either side of them a proper intake cycle. (they'll run lean, and twins often won't start) My first such repair was on a Suzi 550 triple some 40 yrs ago. Easy to diagnose since one cyl ran fine while two didn't. Center cyl and the one side smoked a lot, but it was ridden to my 'shop'.

Using starting fluid (ether, etc) can cause catastrophic damage to two cycle engines (ask a snowmobile shop mech). If a backfire belches into the crankcase it can easily cost you a seal or two, and that's the milder version of why many won't use it a second time. (+1 on the propane test for intake leaks)

With a carb that bad I'd vet the possibilities there thoroughly before tearing down the CC, in case that's all you have to fix. If experienced with cleaning the type, you'd know once you got it right. Diaphragm damage is easier to acquire than to detect. All analyses are easier once running, even if barely.

 

[Clint S]

center crankshaft seal
Yes clean the carb first.

 

[JRobyn]

I've been educated. Didn't consider (and don't have much experience with) multi-cylinder 2-cycles.

 

[stevem5215]

That carb is junk. Don't even bother trying to make it work. Get a different one like a Mikuni.

I'm always amazed at the big lie "it was running when it was shut off" that keeps getting perpetuated all the time. There's should be a giant electrode that shocks the person each time they say it to someone.

Steve