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

[RI Chevy]

More POWAH

 

[mdavlee]

Tuning is way easier. Even a stock 7900 wants to run higher than the coil. On most of them they were faster in the cut with the limited coil. It’s just a handicap when cant racing.

 

[RI Chevy]

I wonder why they came with limited coil?

 

[Fruecrue]

Thanks for the info.
Does the wire still need to go under the coil in the same way, just carry on up and over? What do you do about the 90° bend into the coil?
Sorry for being simple, but electrics are not my thing, what type/ gauge wire will I need?

I have the diagram for flywheel set up. The key has sheared off mine so thought might as well do the 272 coil mod, starting to wonder if it’s worth the effort [emoji849]

I use a .050” washer under the coil at each mount. Spaces it up to bind the wire less but not so much as to affect coil alignment with the flywheel.
I’ve done two and not had to change plug wires yet.
Takes some doing to get it to lay just right.
Worth it in the end.

 

[Wilhelm]

A stock 7900/7910 will hit the rpm limiter under load?!
That is 13500rpm for a PS-7900 coil, or 12800rpm for a PS-7910 coil.
Never heard that before, but OK if the internet says so than it must be true.

Question, if a stock 79 is such a hot rod to hit the limiter under load kant racing why mod them in the first place when all one gotta do is swap the coil out?

Never mind me, I am having a week long headache. . .

 

[Fruecrue]

A stock 7900/7910 will hit the rpm limiter under load?!
That is 13500rpm for a PS-7900 coil, or 12800rpm for a PS-7910 coil.
Never heard that before, but OK if the internet says so than it must be true.

Question, if a stock 79 is such a hot rod to hit the limiter under load kant racing why mod them in the first place when all one gotta do is swap the coil out?

Never mind me, I am having a week long headache. . .

If you are referencing Mike’s post, I believe you are misunderstanding it.

 

[Wilhelm]

Tuning is way easier. Even a stock 7900 wants to run higher than the coil. On most of them they were faster in the cut with the limited coil. It’s just a handicap when cant racing.

 

[Fruecrue]

In the cut was a later reference, a comparison between limited and non.
I can’t speak for Mike but I believe the sentence you highlighted was not meant as “in the cut”.

 

[Wilhelm]

OK, I may have gotten the post wrong, and no I was not solely replying to Mike's post but Keith's as well.

Point is, a stock saw does not NEED an unlimited coil.
Whether an unlimited coil will simplify tuning greatly depends on the operator.
Isn't the most common reply regarding a saws tune "tune under load, in the cut"?

I apologize for overstepping my pay grade and/or stepping on anyone's toes!
I am backing up, will delete my recent posts if desired.

Cheers

 

[Fruecrue]

I apologize for overstepping my pay grade and/or stepping on anyone's toes!
I am backing up, will delete my recent posts if desired.

Cheers

Not like that at all.
Your opinion is as valuable here as any.
I’m over here sticking my nose in a conversation that didn’t originally involve me so I’m probably at fault as well.
Cheers brother, hope the headache clears up.

 

[Deets066]

OK, I may have gotten the post wrong, and no I was not solely replying to Mike's post but Keith's as well.

Point is, a stock saw does not NEED an unlimited coil.
Whether an unlimited coil will simplify tuning greatly depends on the operator.
Isn't the most common reply regarding a saws tune "tune under load, in the cut"?

I apologize for overstepping my pay grade and/or stepping on anyone's toes!
I am backing up, will delete my recent posts if desired.

Cheers

It’s all good, I just have a problem with authority... and limitations

 

[mdavlee]

OK, I may have gotten the post wrong, and no I was not solely replying to Mike's post but Keith's as well.

Point is, a stock saw does not NEED an unlimited coil.
Whether an unlimited coil will simplify tuning greatly depends on the operator.
Isn't the most common reply regarding a saws tune "tune under load, in the cut"?

I apologize for overstepping my pay grade and/or stepping on anyone's toes!
I am backing up, will delete my recent posts if desired.

Cheers

Most people have no clue how to do that. A given rpm to go to with a tach is much easier like say a 346 wants to be happy at 14.3k. A 7900 is happy up near 14k. There’s some out there that will be bumping 13k in small cants. 12k isn’t uncommon on modded ones in bigger stuff.

 

[huskyboy]

I will say I like the 13.5 coil much better than the 12.8 coil in my experiences, that’s all I have to say regarding coils with these saws lol. It’s not because of a power difference necessarily. It’s more because of the ease of tuning.

 

[huskyboy]

Also... if your work saw is turning past the 13.5k limiter in the cut your chain is probably dull. Lol

 

[huskyboy]

I think they put limited coils on these saws to keep the crank and flywheel in one piece... from hacks that run dull chains. Bottom end longevity. Just a guess.

 

[Poleman]

I always leave the original plug line in place and just unscrew it and screw it into the new coil....less missing that way. Yu may have to slit the protective covering an inch or so.
I also super glue two small washers to the case to lift the coil ever so much for clearance for the plug wire.
You'll need the enlarge or egg shape the coil mounting holes to get a little adjustment to set the coil air gap.
I presume you know how to advance the coil after removing the key.

 

[Poleman]

I agree with huskyboy on the factory's ideas on rpm limits. I think it was because of user abuse and lack of knowledge. I think the biggist thing was scored cylinders from running yo lean. The factory changed the rpm limit to a lower speed to help prevent this and warranty claims.
Running the 12,8 coil leaves a lot on the table in my opinion.

 

[Deets066]

I agree with huskyboy on the factory's ideas on rpm limits. I think it was because of user abuse and lack of knowledge. I think the biggist thing was scored cylinders from running yo lean. The factory changed the rpm limit to a lower speed to help prevent this and warranty claims.
Running the 12,8 coil leaves a lot on the table in my opinion.

The limited coil shouldn’t have any affect on lean it runs though

 

[Poleman]

Check out the "7900 Coil Swap" for more info. I did it a few years back and thought I had made a step by step guide on how to do it ( or how I do it).

 

[Poleman]

Deets, I was referring to the 13,5 coil and users leaning the saw out to much and causing scored cylinders. It’s a lot harder on a 12,8 Saw.
I think thats why most every maker out there went to limited coils was for warranty claims and possible EPA. Every day that comes out now are pretty much set as lean as possible to make the EPA happy. Dealers need to adjust EVERY saw they sell to make sure it’s adjusted properly.... if they don’t they usually come back with an unhappy customer.