# FS55 timing



## Kebo57 (Jul 26, 2021)

Hi this will be my second thread.. having got quality help in my first post I’m back with another problem.. I’ve got a fs55 strimmer that won’t fire let alone start.. barrel, rings, piston, compression & coil are all good, I’ve strobed this engine and it looks like the timing has moved, I’ve took two pic 
1st is at TDC 
2nd is where I think the flywheel should be at TDC 
Any help will be greatly appreciated
Thanks


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## cscltd (Jul 26, 2021)

remove flywheel and check for damage to flywheel key, if ok, then could be frankensteined with wrong flywheel from other 4140 series engine


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## Kebo57 (Jul 26, 2021)

Thanks key has slight damage but locates see pic, 
so it might have the wrong flywheel, will there be numbers on the flywheel that will show incorrect flywheel


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## frank_ (Jul 26, 2021)

looks like an hs f/w to me, they have the keyway at 12 o,clock


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## Kebo57 (Jul 26, 2021)

Thanks so for.. I have a 
4140 engine & a
4140 flywheel
See pic


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## Kebo57 (Jul 27, 2021)

Also a 4140 crank see pic.
The third pic shows the keyway at 12 o’clock my keyway is at 10 o’clock.. is this the error relating not starting.. any help would be greatly appreciated


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## frank_ (Jul 27, 2021)

that f/w fits about 30 different models eh, so stihl must keyway the crank according to the position of the coil
hs45 crank and f/w keyways are both at 12 o,clock, and coil is mounted at 11 o,clock








Flywheel for Stihl FC55, KM55 Edger - 4140 400 1200


Flywheel for Stihl FC55, KM55 Edger Genuine Stihl Part OEM Part No. 4140 400 1200 Suitable for the Following Applications: FC 55, KM 55, KM 55 C, KM 55 R, KM 55 RC, HS 45, BR 45 C, BT 45, HL 45, FS 38, FS 45, FS 45 C, FS 45 L, FS 46, FS 46 C, FS 55




www.lsengineers.co.uk


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## Kebo57 (Jul 27, 2021)

Ok thanks once again.. I will reset the crank shaft with key at 12 o’clock


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## frank_ (Jul 27, 2021)

Kebo57 said:


> Ok thanks once again.. I will reset the crank shaft with key at 12 o’clock


different coils may have a different dwell programmed tho eh, here,s the hs


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## cscltd (Jul 27, 2021)

There was 2 different cranks used on fs55, 4140 030 0400 and 4140 030 0401


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## Kebo57 (Jul 27, 2021)

Kebo57 said:


> Ok thanks once again.. I will reset the crank shaft with key at 12 o’clock


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## Kebo57 (Jul 27, 2021)

Thanks.. I’ve 1/2 pressed out the crank shaft & turned it to 12 o’clock see pic.. will press it back together & try it shortly


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## Kebo57 (Jul 27, 2021)

Kebo57 said:


> Thanks.. I’ve 1/2 pressed out the crank shaft & turned it to 12 o’clock see pic.. will press it back together & try it shortly


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## Kebo57 (Jul 27, 2021)

frank_ said:


> different coils may have a different dwell programmed tho eh, here,s the hs
> 
> View attachment 920737


Ok I’ve marked TDC in white marker on f/W & coil.. strobed with electric drill at 2000 rpm & white line is at 2 o”clock so defo something amiss.


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## Kebo57 (Jul 28, 2021)

I’ve got it all back together & it’s running well.. didn’t want to start but 20 sec help with makita 18v drill sorted that..
For me the problem was a strange one.. waiting for feed back from the owner will let you all know the out come
Thanks once again for all your help


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