5100s coil options

[rbmopar]

I have a couple 5100's that have hot start problems that I figured out have failing coils. From what I can see the grey 14,500 unit that these have went NLA a few years back, but now it looks like they quit making the 13,500 coil too. So, I ordered a couple aftermarket ones and tried them tonight. The timing is too advanced with these china coils, bites back HARD trying to start, and runs poorly. I have 2 and they both did the same thing, so I don't know if these were meant for a 5105 or what. If anyone knows of a source of oem coils would be best, but if there is an aftermarket one known to work with the 5100s, that would do the trick too. Thanks, Randy

 

[Wonkydonkey]

Have you tried making the flywheel gap bigger, I’ve heard it retards it a bit.. or you could try a few other ways of retarding the timing a bit ? Ie filed key in backwards (most of us want a bit of adv)

 

[Wilhelm]

All my "large frame" Dolmars, 64xx/73xx/79xx, have hot start issues!
By summing up forum entries this is supposedly a carburetor issue and can be fixed with Walbro carb parts (spring) placed into the OEM Zama carbs.

I have not tried it yet, but I thought it might be worth mentioning before You venture into a costly road into coil replacements.

FYI, many Dolmar saws listed on German eBay state "new OEM coil".
I find this very suspicious as I have yet to encounter a failing or failed coil myself - knock on wood!

Just a friendly FYI.

 

[rbmopar]

I used these as bucket saws in my tree service for a few years and a new one would work great with no issues for 6-9 months. Then hot start issues would start happening, but only once or twice a week. Another month of that and the problem was once or twice a day. In the bucket that is super aggravating, so we would put the old one on the shelf and grab a new saw. Went through this with three different saws. They have been sitting for a few years and I figured it was time to figure out what the problem was, as I was never sure if it was fuel or spark. I took the first saw that developed problems out to the wood pile and made enough back to back cuts to get it good and hot, then let it sit for 10min. Would not start as expected. Checked for spark and there was none visible in daylight. Took it back to the shop with the lights off and there was a tiny bit of weak orange spark if you pulled it over really fast. Checked again an hour later and it had a nice blue spark. Bad coil. As for trying to adjust the timing with the aftermarket coils that I have, I will play with that but would still like to find a bolt on replacement. Thanks guys

 

[Shane¹]

I am going to say aftermarket and retard the timing some maybe your only option. I would say once you figure one out it will probably be the same on all 3