Runs on choke

[Dan Forsh]

Guys,

I think I've explained my involvement in saws before, but I will go there again for the benefit of those who might not know.

I'm relatively new to saws, never owned or ran one before February last year. To date I've owned... (pauses for a moment to check the spreadsheet) 33, of which I've since sold 15. So my my involvement is very much buy em, fix em, sell em. I have very few hours behind a saw.

One question that I need some experienced answers to is this:

When starting a saw from cold, is it normal for some saws to want to continue running when popped on choke?

I'm used to the standard start up procedure of pull till she pops, choke off then pull till she fires, but once in a while I'll get a saw that will run on choke when it pops.

Is this just the differences between saws, or as I suspect, potentially an air leak somewhere?

Cheers,

Dan

 

[Lakeside53]

It can be either an air-leak, or a bad fitting choke...

 

[retoocs555]

I've found that is normal on some saws, mostly older models. They seem to just lug along with the choke closed until you open it up.

 

[GPH85]

Yeah, what he said...

retoocs555 - I've found that is normal on some saws, mostly older models. They seem to just lug along with the choke closed until you open it up.

AND, if on newer saws, what he said...

Lakeside53 - It can be either an air-leak, or a bad fitting choke...

Seriously, on my older saws, I just crank them and let them idle until just before they go to die, then push the choke in. This helps to build up fuel in the carb.

On newer saws, they tend to just hit once on choke, then push choke in and they run fast because the choke sets the throttle higher. Squeze the throttle and she's good to go.

I guess you could say it's just newer carbs vs. older carbs

 

[Lakeside53]

Yes, the older saws do tend to chug on more. Many of the older carbs have a hole in the choke butterfly... That can contribute to a "run" condition".

It also depends on the saw. Many of the old Macs and Echos I've worked on actually needed partial choke for say 15 seconds. A newer (20 years) Stihl is either on (suck gas for starting) or off.

My comment on the "bad fitting choke" come from 028's and 038's.. They tend to chug with the choke on more than others.

If you have a modern saw that run with the choke on, look for the problem.

 

[Dan Forsh]

Thanks for all the replies guys. That was exactly what I needed to hear. I am specifically talking about older saws.

Andy, one of the ones that this has been happening on is indeed an 028.

Cheers,

Dan