Dolmar 64xx/73xx/79xx series, smurfs and solo 665/675/681 thread

[Time's Standing Stihl]

I need to get a family picture

 

[dustinwilt68]

Got 3 more red saws coming in from Germany, should ship next Tuesday the seller says

 

[rocco490]

Got 3 more red saws coming in from Germany, should ship next Tuesday the seller says

are they still in production?

 

[dustinwilt68]

Not sure honestly. That's why I got 2 for myself

 

[StuntCockWelder]

I need to get a family picture

Looks awesome!!!

 

[StuntCockWelder]

Not sure honestly. That's why I got 2 for myself

And an extra for me thanks again Dustin!

 

[stranter]

I prefer an unlimited coil, simply like the option to check tune while not in the cut.
Not here to debate that.

A while back I played around fitting up alternative coils on my Smurf 84/6401, the 272 coil works fine but I was looking for something that would be a direct swap.
No such luck but did find a couple readily available types I had on hand that mounted with very little modification and with no need to swap out to the dolmar core.

First was from an 025, a bunch of the small stihls like 018's also use this or similar, only needed a notch filed in next to the original outside mounting hole to fit up.

View attachment 136058

The plug wire is located in a good useable spot but unfortunately is permanently affixed in place. Not difficult to dig the wires insulation out from around the conductor, then just stuff the dolmar wire into the cavity. The 025 wire goes almost all the way to the bottom of the coil, so theres plenty of depth for a solid connection.
Or just graft the two wires together.

I wasn't leaving this coil in permanently so just to try it out, put the dolmar wire in the spark plug boot and was able to route the 025 coil wire around and about so to still allow the starter cover to fit over it all.


Another somewhat less common coil that fits up is one from a bg55/85 blower, still readily available used on feepay or as aftermarket for about $14. I found a used one for $9 that I got for a blower and happened to be sitting on the bench while I had the Smurf apart.
A little bit of elongating of the lower mounting hole was about all it took to get a decent fit. Small chain file is about the right size for this task.

View attachment 136059

Same issue with the non removable plug wire unfortunately, still in a good location though.
Timed it the same way as the 025 and again ran fine. Much shorter plug wire so easier than the 025 coil to route without cutting the wire/boot off.

You do still need to grind/file the key off the flywheel, the timing is pretty far off from the original coil, seems dolmar has their own scheme that deviates from typical convention.

Somewhere here or over on AS I ran across a nice technical drawing sort of pic that showed an easy way to time a 272 coil conversion and worked fine here on the first try.
No degree wheel or other timing method needed.
Saw would tune to 14.3k with either coil no problem.

With piston at tdc, the trailing edge of the flywheel magnet block gets lined up with the trailing edge of the leading coil leg as can be seen in the bg55 coil pic.
Sooner or later when I get around to modding the saw I'll play around with moving the timing a bit.

Great post.
I would like to try a 272 or 025 coil on my 7910. I have seen the diagram for correct timing so that’s all good.
But do I need to connect the dolmar wires? If so can someone explain to a simpleton (me) how to go about digging the wires out on the coil and connecting them? Pictures would be ideal.

Thanks

 

[3browns]

I need to get a family picture

Awesome!!!

Is that hockey/friction tape overwrap?

 

[Time's Standing Stihl]

Awesome!!!

Is that hockey/friction tape overwrap?

Pretty much. Think this stuff came from a bicycle store. I use baseball/tennis grip too

 

[3browns]

Pretty much. Think this stuff came from a bicycle store. I use baseball/tennis grip too

Interesting

I tried road bike handlebar wrap once years ago and it gripped and felt great but it didn't like the petroleum rich environment and basically disintegrated over a summer

Probably got my moneys worth though...

 

[ajschainsaws]

Interesting

I tried road bike handlebar wrap once years ago and it gripped and felt great but it didn't like the petroleum rich environment and basically disintegrated over a summer

Probably got my moneys worth though...

You can use vetrap or a cohesive bandage it works well and it won’t move
The more you hold onto that sucka the tighter it goes

 

[3browns]

You can use vetrap or a cohesive bandage it works well and it won’t move
The more you hold onto that sucka the tighter it goes

Hadn't thought of that

I have some C0-Ban and will clean the bar up and try a couple wraps in the 12:00 and 9:00 positions

If it lasts I will pull the bar and do the whole thing

Thanks!!!

 

[StuntCockWelder]

I used Easton bat wrap it worked ok.. doesn’t clean very good tho

 

[3browns]

View attachment 180135 I used Easton bat wrap it worked ok.. doesn’t clean very good tho

Nice!!!

 

[wcorey]

Great post.
I would like to try a 272 or 025 coil on my 7910. I have seen the diagram for correct timing so that’s all good.
But do I need to connect the dolmar wires? If so can someone explain to a simpleton (me) how to go about digging the wires out on the coil and connecting them? Pictures would be ideal.

Thanks

Not really clear on what exactly you're unclear about.
It's just a plug wire and kill switch wire, plug wire I more or less explained in the post and IIRC the kill wire should just plug right in to the 025 spade terminal same as the original coil.
The 025 plug wire isn't long enough so needs to be modified to work.
If you don't want to swap out the entire non-unscrew-able plug wire from the 025 coil you can cut it partway and splice/connect the dolmar plug wire on to it.

 

[stranter]

Not really clear on what exactly you're unclear about.
It's just a plug wire and kill switch wire, plug wire I more or less explained in the post and IIRC the kill wire should just plug right in to the 025 spade terminal same as the original coil.
The 025 plug wire isn't long enough so needs to be modified to work.
If you don't want to swap out the entire non-unscrew-able plug wire from the 025 coil you can cut it partway and splice/connect the dolmar plug wire on to it.

Thanks for the reply. I think I was just being a bit slow. Makes more sense in my head now.

 

[dustinwilt68]

Love to see pics of the 025 setup, does it need shimmed like the 272 coil?

 

[wcorey]

Love to see pics of the 025 setup, does it need shimmed like the 272 coil?

Pic in post #29.
No shims.

 

[Yotaismygame]

Got this done over the weekend. Still needs broke in. It's for sale..

 

[Yotaismygame]

Here's a 6421 with a big bore kit on it. Only has a modded muffler, base gasket still intact. Saw had terrible throttle response off idle before I modded the muffler. This is before I started porting. Maybe someday I'll get around to porting it.

Got a few of these smurf saws in my possession right now.