bmp01

Picture paints a thousand words… impulse line location and swap, have a look here, at 1/4 - 1/3 of the way in.

I think that was the plan until Openspaceman found that the coil had stopped sparking all together (going by the posts above …)

Sounds like progress 🙂 thanks for the updates.

….best on no choke…. What does that mean? I bet it means choke for a dozen pulls, frustration, then trying every other control switch option….🙂🙂🙂 Or am I wrong and it means no choke from first pull? Have you tried 3 pulls on full choke then switching to ‘half choke’ irrespective of it popping on full choke?

A bit of history with that saw then. Aftermarket coil rings alarm bells for me. What about a strobe light, could you use that at pull cord speed to see where it’s sparking? Does the flywheel have features to pull it off nicely - I expect Spuds workshop manual (posted earlier in the thread) would tell you.

Maybe but I’ve not owned one so can’t add detail, sorry. Could be a few different flywheels/ coil combinations to mess up timing…. I guess you’ve tried Spuds bend the plug terminal to get the spark to jump bigger gap…establish if coil is really healthy (not just pretending ) ……. heading off piste here aren’t we…..

That was my understanding too, just wondered if Pleasant knew different….. it was 2023 when that message was posted, I’m sure Esso have had to toe the line….

The Esso fuel being zero ethanol in the past, is it still true ?

Nope. Turning the screw clockwise is ‘closing the tap’ - saw will run leaner. In your other comments you said turning screw counter-clockwise helped the saw run better (for a bit) - in this case you were adding extra fuel …. It’s likely the extra fuel is helping compensate for an air leak or an issue with fuel delivery. Be cautious, find the cause for the original failure before it repeats. I know this is repeat advice, Stubby, but…..well… it’s right innit.

😆 ....sharp intake of breath.... did you just 'dis' a Stihl ? 😨

Well, saw is fixed with the new carb so its no longer going in the skip - thats a good thing. As for the above - I agree with what youve said. Ref the video of it: - Most saws die on choke with over rich mixture (not all, but most). - Didnt revup properly once throttIe was opened, think it was just spooling down from there with out any more combustion. I dont think it had a full metering chamber of fuel (after runniny on choke), I'd guess its pulling in fuel and air into the metering chamber while on choke and thats why it kept running (on choke) and didnt die (over rich). Its just that on choke theres such a high vacuum on the fuel circuit that even with an air leak there is still enough vacuum to pull some fuel though. Either that or the diaphragm's too stiff or wrong version and just not operating the metering arm. But anyway all somewhat irrelevant now.

The fact it wasnt running right since the last bad repair hasnt stopped the guy from using it - judging by the chain imprint (wear) in the spur gear teeth. No sense of mechnical sympathy = bigger repair bill.

I presume it had the rails with it ? Works ok once rails are set up on a straight plank, just a bit of effort to get to that stage.

Might be the picture, dunno, but that metering arm looks a tad low ? Quite a jaunty angle too, I'd be tempted to tweek it up a bit and then bend the contact face so its parallel to adjacent carb recess, maybe Im a bit OCD ??? 🙄

Always nice to be completely sure about its itegrity and tick it off the list of suspects. Onwards.....