Coleman 550 Loose Timing Chain

[Copperline]

I have a Coleman 550 (hisun). Wouldnt start and was sucking instead of blowing through the spark plug hole. Got to the timing chain and it was very loose and for sure the timing was way off. Got the tensioner off and set it to TDC and got the cam gear back aligned. Put the chain back on and set the tensioner as instructed and the chain is still very loose. I extended the tensioner as far as it would go to test and the chain is still loose. 

Any ideas what could be broken or wrong? Why would the chain be so loose?

 

 

[Travis]

Wild guess would be that the chain has stretched from heat and wear. Hisun isn't exactly the industry leader in quality parts.

[Copperline]

I think you are right. 

I'm just getting into the process of replacing it and struggling to get the flywheel nut off. 

[Travis]

9 hours ago, Copperline said:

I think you are right. 

I'm just getting into the process of replacing it and struggling to get the flywheel nut off. 

get some paracord or small rope, remove a spark plug, insert the rope into the plug hole until the cylinder is full (won't take anymore), remove the nut.

i've used this method many many times.

[Copperline]

I ended up just fabricating a tool to make it work. A 16" pice of thick steel plate about 4 inches tall. Drilled a big hole about 3" from one end to allow the socket to fit and then two outside holes to put long bolts into the flywheel (I removed two of the flywheel allen bolts). This allows the tool to jam against the frame of the cart and I was able to remove the nut easily with no damage. 

[aefron88]

On 1/15/2023 at 9:54 AM, Travis said:

Wild guess would be that the chain has stretched from heat and wear. Hisun isn't exactly the industry leader in quality parts.

Yep likely stretched. Buy a new chain and compare lengths and I bet the new one is shorter.

[Copperline]

I replaced the timing chain as well as the oil chain. Hopefully that does it. Working on this inside the frame has been horrible. I cracked an oil gear tooth trying to keep the engine from turning while trying to get the flywheel off. Two years is really too short of a time to have to be tearing this apart for chains.