White smoke coming from exhaust on Stihl 201TC

[Pete Mctree]

If you run it rich enough it will smoke - OP said that it was running well.

[openspaceman]

1 hour ago, AHPP said:

Or something like chain oil dripping onto the exhaust maybe.

Can chain oil leak into the crankcase if the crankcase gasket slips on this saw?

[Retired Climber]

49 minutes ago, Pete Mctree said:

If you run it rich enough it will smoke - OP said that it was running well.

My hedge cutter runs well, but is still smokey. Can you explain what you mean by 'run it rich'. I've seen all sorts of uses for the term on this forum, so I'd be grateful if you could clarify. 

[AngrySquirrel]

41 minutes ago, Retired Climber said:

My hedge cutter runs well, but is still smokey. Can you explain what you mean by 'run it rich'. I've seen all sorts of uses for the term on this forum, so I'd be grateful if you could clarify. 

Fuel mixture too high in petrol to air values and lower performance of engine the more it smokes ie a low compression engine will smoke more than a high which would most likely be able to use the extra fuel till becomes too far out of values!

[openspaceman]

58 minutes ago, Retired Climber said:

My hedge cutter runs well, but is still smokey. Can you explain what you mean by 'run it rich'. I've seen all sorts of uses for the term on this forum, so I'd be grateful if you could clarify. 

This can depend on the engine. Hedgcutters, unlike chainsaws, tend to work on high idle a lot, as they often have rev limiters which cut the spark they can have a lot of unburned fuel escaping and the oil can condense out in the exhaust.

[Retired Climber]

21 minutes ago, AngrySquirrel said:

Fuel mixture too high in petrol to air values and lower performance of engine the more it smokes ie a low compression engine will smoke more than a high which would most likely be able to use the extra fuel till becomes too far out of values!

Thank you. That's my understanding too, bit I've seen people quoting having too much oil in the fuel mix as both lean and rich on this forum. 

[Retired Climber]

6 minutes ago, openspaceman said:

This can depend on the engine. Hedgcutters, unlike chainsaws, tend to work on high idle a lot, as they often have rev limiters which cut the spark they can have a lot of unburned fuel escaping and the oil can condense out in the exhaust.

Thank you, that's interesting. I've never thought of it like that. 

[openspaceman]

19 minutes ago, Retired Climber said:

Thank you, that's interesting. I've never thought of it like that. 

Oddly enough my neighbour is having his hedge cut by an arb firm, mob handed, 5 blokes three trucks and a chipper. I can hear the hedgcutter on its high limit all the time.

 

I found the problem worst on the BT45 drills which were lovely machines for speed but would frequently block their spark arrestor in the exhaust with oily gunk. The lads would muck around with the mixture screws as they didn't understand why the engine was running rough yet the remedy was simply to remove the spark arrestor and burn off the muck with a blow torch.

 

Even though I modulate the throttle on my hedgecutters to suit the load I find the exhaust has an oily build up yet the chainsaws never do because they run full throttle with the load setting the revs.

[Retired Climber]

10 minutes ago, openspaceman said:

Oddly enough my neighbour is having his hedge cut by an arb firm, mob handed, 5 blokes three trucks and a chipper. I can hear the hedgcutter on its high limit all the time.

 

I found the problem worst on the BT45 drills which were lovely machines for speed but would frequently block their spark arrestor in the exhaust with oily gunk. The lads would muck around with the mixture screws as they didn't understand why the engine was running rough yet the remedy was simply to remove the spark arrestor and burn off the muck with a blow torch.

 

Even though I modulate the throttle on my hedgecutters to suit the load I find the exhaust has an oily build up yet the chainsaws never do because they run full throttle with the load setting the revs.

I'll have a look at the spark arrestor, thanks. It's never been serviced since I bought it, other than me changing the spark plug and fuel and air filter. 

[openspaceman]

2 minutes ago, Retired Climber said:

I'll have a look at the spark arrestor, thanks. It's never been serviced since I bought it, other than me changing the spark plug and fuel and air filter. 

I only came across a spark arrestor on the drill, if the Stihl hedge cutters have it it must be in the silencer, I've just gandered in my HL75 with a torch and there is none. If the exhaust looks oily just heat it up  off the machine to burn it off.