025 impulse line? or other culprits

[osteoart]

I have just replaced the fuel line and original Walbro 283B fixed high carb with a 215 knock off carb. Deleted spark screen and opened muffler a small amount. Made all carb adjustments going into and then out of hardwood.
This old 25 is cutting good, starting good, but... when first started it idles VERY high when the saw is cold even after kicking off the high idle catch. Once it warms up it acts fine. I did not replace the impulse line as I don't know how to get to it. How do I get to the impulse line to replace it? Other things to look at? Thanks.
Carl

 

[Wood Doctor]

Might be a cracked fuel line. Check the fuel line connection to the carb. These are notorious for giving up right there because it's bent around in a cramped area. If cracked, it will est up erratic running behavior.

 

[osteoart]

Thanks Doc but fuel line is new.

Might be a cracked fuel line. Check the fuel line connection to the carb. These are notorious for giving up right there because it's bent around in a cramped area. If cracked, it will est up erratic running behavior.

 

[fearofpavement]

The symptoms don't really coincide with a bad impulse line. Also, I have rarely encountered a bad impulse on this series of Stihl.
Did the problem precede the recent changes?

Engines need more fuel when cold than they do when hot, I think the saw is lean until it warms up. Try richening the H a bit and see if it changes the cold start symptoms.

Also, see if perhaps the throttle plate or choke plate is sticking.

 

[Wood Doctor]

The symptoms don't really coincide with a bad impulse line. Also, I have rarely encountered a bad impulse on this series of Stihl.
Did the problem precede the recent changes?

Engines need more fuel when cold than they do when hot, I think the saw is lean until it warms up. Try richening the H a bit and see if it changes the cold start symptoms.

Also, see if perhaps the throttle plate or choke plate is sticking.

+1 here. I was trying to figure out how the engine was running lean on startup and then smoothing out later. Backing out the Hi speed setscrew might help, but that usually helps only at the top end. OP said this engine was running high on idle.

I'm starting to suspect crank case seals that leak initially and then somehow tighten up after running. I've never run into that, but I suppose it's possible.

 

[osteoart]

The symptoms don't really coincide with a bad impulse line. Also, I have rarely encountered a bad impulse on this series of Stihl.
Did the problem precede the recent changes?

Saw had stopped running before carb replacement.

Engines need more fuel when cold than they do when hot, I think the saw is lean until it warms up. Try richening the H a bit and see if it changes the cold start symptoms.

Also, see if perhaps the throttle plate or choke plate is sticking.

Both OK.

Got it thanks. I just richened both H and L ever so slightly, 1/8 turn or less and saw is running right now. I also had to add a little LI to the throttle plate now to keep it running on idle. Boy is this new carb sensitive to adjustments! Got to get out now to cut and stump spray more bush honeysuckle. Thanks again .

 

[idiotwithasaw]

I had an ms250 where the ends of the impulse line were swelled out over time and were letting air in past the nipples. However that saw ran like you would expect a saw with an air leak to run. I suspect the am carb. A new oem zama carb is $21 at my local dealer, with hi lo screws. If you were going to keep this saw I would replace with oem and go on.

 

[osteoart]

I'll keep an eye out for a decent price on a Walbro 215. This saw started life out with a Walbro 283B. I'm keeping the saw, I have been through two new bars a spur sprocket and too many loops to count and the saw is still strong. I've never had a 026 so I guess I don't know better than to consider my 025 a "good" saw.

 

[idiotwithasaw]

I would try your dealer first. With the exception of my 066 new carbs from the dealer are cheaper than I would have thought. They may be able to get a wt215. Never hurts to ask. Just my $.02

 

[fearofpavement]

Glad you have the saw back online. Nothing wrong with an 025, they've cut a lot of wood for a lot of people.

 

[osteoart]

Glad you have the saw back online. Nothing wrong with an 025, they've cut a lot of wood for a lot of people.

Thanks for the encouragement fop. I'm not a saw snob nor a beer snob. I'll drink any brand of cold brew on Sunday, and use any saw that has a sharp chain on it. I see that you have three 026's and no 025. So you probably want to swap me one of your 026's for my saw ?
Carl

 

[fearofpavement]

I have a pile of 1123 saws, as of now they're just parts in totes. Come winter some of them will be getting assembled. Most are of the 021 flavor but any that need engines will become 025's.
So you can add to your collection in 6 months. lol.
I think I've had a couple of MS250s but never had one in my line up. I also have another 026 that hasn't been triaged yet.

 

[osteoart]

I have a pile of 1123 saws, as of now they're just parts in totes. Come winter some of them will be getting assembled. Most are of the 021 flavor but any that need engines will become 025's.
So you can add to your collection in 6 months. lol.
I think I've had a couple of MS250s but never had one in my line up. I also have another 026 that hasn't been triaged yet.

So another 026 "four" you and I have none. Sounds suspiciously like UGA vs UK football depth chart. Ah well such is life as we live it.
Sorry for getting off the subject matter.
Carl

 

[fearofpavement]

I know diddlysquat about football and don't even know (or care) what a depth chart is. I do like saws though...

 

[Wood Doctor]

Both OK.

Got it thanks. I just richened both H and L ever so slightly, 1/8 turn or less and saw is running right now. I also had to add a little LI to the throttle plate now to keep it running on idle. Boy is this new carb sensitive to adjustments! Got to get out now to cut and stump spray more bush honeysuckle. Thanks again .

That's another problem with the 025. The carb adjustments are overly sensitive. They eventually started sending out carb replacements with practically no adjustments available. In fact, some 025 replacement carbs require that you remove the carb entirely to make a low-speed adjustment. Figure that one out.

 

[osteoart]

Thanks for the replies. Ran the saw yesterday and it's holding tune now. Now that I think about it I have changed fuel mix now feeding it the Shindawa red armour . Maybe the change from my old mix to this "new stuff" caused it to lean out a little? Anyway, running great again.