Husqvarna TC138 issue starting

[willevans9@gmail.com]

I have a husqvarna tc138 and am struggling to get it to start.
When I turn the key the starter motor activates and does an initial attempt at spinning the engine but quickly grinds to a halt. The battery voltage is fine - fully charged. I have bypassed all wiring with jump leads and the same issue occurs ( I have also done this and removed the positive connecting cable to check this was no grounding out). I have taken the starter motor off and appears to be working fine, spinning freely and fast under the battery voltage. I am now thinking it might be something to do with the flywheel. When the starter motor spins it sort of grinds to a stop (very quickly). I have to manually release it by moving by hand. This seems to release the pressure in the piston and then I can try it again but then same problem.

It was working fine last year but at the end of the season the belt came off so I have just put that back on. It has been sat under a cover over the winter (not ideal) hence my thinking it was an electrical issue. I am at a bit of a loss now. Anyone have any ideas?

Thanks!

[Mick]

Hi Will, and welcome to TGMF.

Have you tried removing the spark plug and see if it spins over ok like that.  Sounds to me like the decompressor on the camshaft isn't working, so as soon as it hits compression it stops. You could also try turning the engine backwards by hand half a turn or so, and then try engaging the starter again.

It could be valve clearances need adjustment, but to be honest this doesn't normally just happen suddenly unless something comes undone.

 

[willevans9@gmail.com]

Hi Mick, thanks for the suggestion. No I have not tried that - I will give it a go 👍