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

[PA Dan]

Could I possibly remove the flywheel nut with an impact tool, or best with a piston stop and wrench?

I hold the flywheel and use my 1/4" impact.

 

[RI Chevy]

Use some nylon pull cord and shove it in the plug hole for a piston stop. Leaving a little out so you can remove after.

 

[kingOFgEEEks]

Could I possibly remove the flywheel nut with an impact tool, or best with a piston stop and wrench?

I use an impact. Quick ugga dugga and the nut is off.

 

[Stefaan]

The key is cast in so u have to use a thin burr on it it with whatever power tool you have. Aim is to grind enough off the key to turn the flywheel counter clockwise 1-2 fin widths which is a couple degrees (about 1/4-1/3 key width). No real science to it. If it cuts faster with the advance and don’t pop in the cut your good. If it pops and no performance improvement dial it back a little. You should notice a minor torque gain.

Does the timing advance both applies to the 7300/7900 and 7310/7910, Mason? Because they use different coils.

 

[huskyboy]

Does the timing advance both applies to the 7300/7900 and 7310/7910, Mason? Because they use different coils.

Yes. If it pops in the cut you know you ground too much off the key and you just retard it a little bit. I usually swap the 12.8k coil for the 13.5k coil since it makes tuning easier and you gain a little more chain speed when topping felled trees.

 

[Stefaan]

Do you need to change the flywheel as well, when you change out the coils?

 

[Johnmn]

Do you need to change the flywheel as well, when you change out the coils?

No

 

[Stefaan]

Couldn't remember if I shared this video allready in this thread. Stock 7300 with only a muffler mod so far. Cutting pine.

 

[Stefaan]

Finally got to the timing advance. So you told me to file away the cast in key on the flywheel, he Mason? It is pretty tiny. Any chances in damaging the flywheel by filing into the cylindrical part instead of the nub?

 

[WKEND LUMBERJAK]

Finally got to the timing advance. So you told me to file away the cast in key on the flywheel, he Mason? It is pretty tiny. Any chances in damaging the flywheel by filing into the cylindrical part instead of the nub?
View attachment 330550

You would have to get pretty aggressive to mess up.

 

[huskyboy]

Finally got to the timing advance. So you told me to file away the cast in key on the flywheel, he Mason? It is pretty tiny. Any chances in damaging the flywheel by filing into the cylindrical part instead of the nub?
View attachment 330550

I just use a small carbide burr on a dremel

 

[MustangMike]

I've done it with a triangular file.

 

[Stefaan]

Thanks for the advice guys!

 

[kingOFgEEEks]

Thanks for the advice guys!

Remember, the key is only for indexing the flywheel. Clean the taper on both the flywheel and crank before installing, so the friction fit will hold things in place.

 

[old_sir_henry]

Are there any aftermarket top-end kits for the 7900 and 7910 available, other than the usual big bore ones?
In Europa, I'm not aware of any, only Golf pistons but no cylinders.
Is north american situation any different?

 

[Wilhelm]

Are there any aftermarket top-end kits for the 7900 and 7910 available, other than the usual big bore ones?
In Europa, I'm not aware of any, only Golf pistons but no cylinders.
Is north american situation any different?

Yes, there are 52mm AM P&C kits!!!
I have seen numerous on eBay.com, from China!

Don't ask me to find any now, I just came from work, 6 day work week, afternoon shift.

 

[Wood Doctor]

HL Supply has them. Lots more are out there. Why rule out a Big Bore kit? My Makita 6401 loves the one I installed with the Wkend LumberJak.

 

[Wilhelm]

There are indications and opinions that the saws crank case volume and carb are not sufficient to feed a 54mm BB kit.

I have 47mm, 50mm and 52mm, all OEM.
I very much like the 50mm the most.

 

[Steve]

There are indications and opinions that the saws crank case volume and carb are not sufficient to feed a 54mm BB kit.

I have 47mm, 50mm and 52mm, all OEM.
I very much like the 50mm the most.

My 54mm bbk ran phenomenal.

 

[Wilhelm]

My 54mm bbk ran phenomenal.

Not saying a 54mm BB kit can not run beyond expectations.
I have a BB kit in my spare stash, but I am not pulling any OEM of my saws just to "try" a BB.