So who has modded there Dolmar 7900??

[JeffandJess4806]

I got a nice shiny new one, I would like to see pics and here info on the pro and cons on the mods. I want to open the muffler maybe a double barrel setup! Who can do the muffler for me? What kind of cost does the muffler mod cost???


Got any pics??


P.S I did search and found some good stuff but i am sure there is more

 

[04ultra]

Mine are kinda Stock.....






.

 

[JeffandJess4806]

Mine are kinda Stock.....






.

Well let see them or here about them

 

[Freakingstang]

Mod the muffler and leave it be. you can port them, and ruin them all in one very easy step. I'm not saying they can't be ported, but there are certain things (like a rev limiter) that help the saw in not doing so well with mods. The port timing is not like conventional Husky and Stihl saws, people try to port em like that and they wind up running worse that stock.

I have played around with a lot of my own saws, but I'll leave my 7900 muffler modded. It runs too good to mess it up.

 

[JeffandJess4806]

Ya i was planing on just doing the muffler. Whats the story with the Stang in your pic? I have a stang or 3...lol 87 notch with 351W S-trimed Puts down some good numbers, 96 Cobra, 95 gt vert

 

[Freakingstang]

Ya i was planing on just doing the muffler. Whats the story with the Stang in your pic? I have a stang or 3...lol 87 notch with 351W S-trimed Puts down some good numbers, 96 Cobra, 95 gt vert

89 notchback. 90K mile shortblock with Iron GT-40 heads, and a bunch of bolt ons. 12.09 was the best ever ET. Kept popping HG's and am in the process of putting it back to stock to sell. old motor made 290/330 to the wheels N/A with iron heads. Most TFS combos put up less than that.... Nothing felt better than smoking a big dollar car with this back yard pile of crap. lol.


My baby is an 86 GT vert with a 306 and S-trim, but I am building a 331 for it right now. it is far from stock. Thinking about going aftermarket block.

My toy is a 66 coupe with a 93 cobra EFI 5.0L and T-5. Car is apart right now for body work (quarterpanels and paint).


I've also got an 86 SSP notch former Utah HWP. Haven't done anything with it yet, but I have papers that states it is one of 38....

might sell that one to fund a new house purchase.

I want a newer one, but I can't get rid of the 86 and the 66. I have pics of the 86 in the readers ride section if you want to check them out.

 

[Simonizer]

89 notchback. 90K mile shortblock with Iron GT-40 heads, and a bunch of bolt ons. 12.09 was the best ever ET. Kept popping HG's and am in the process of putting it back to stock to sell. old motor made 290/330 to the wheels N/A with iron heads. Most TFS combos put up less than that.... Nothing felt better than smoking a big dollar car with this back yard pile of crap. lol.


My baby is an 86 GT vert with a 306 and S-trim, but I am building a 331 for it right now. it is far from stock. Thinking about going aftermarket block.

My toy is a 66 coupe with a 93 cobra EFI 5.0L and T-5. Car is apart right now for body work (quarterpanels and paint).


I've also got an 86 SSP notch former Utah HWP. Haven't done anything with it yet, but I have papers that states it is one of 38....

might sell that one to fund a new house purchase.

I want a newer one, but I can't get rid of the 86 and the 66. I have pics of the 86 in the readers ride section if you want to check them out.

Hey Steve, I had a modded '87 Grand National that LOVED Mustangs and Corvettes. 10.19@141.

 

[JeffandJess4806]

Hey Steve, I had a modded '87 Grand National that LOVED Mustangs and Corvettes. 10.19@141.

I got a little something for your 10.19, I would put my new 7900 on it:biggrinbounce2:

 

[Freakingstang]

Hey Steve, I had a modded '87 Grand National that LOVED Mustangs and Corvettes. 10.19@141.

Grand Nat's are cool. I would like to have one some day.

I hope the VERT will be a low 10 sec street cruiser when it is done

 

[computeruser]

+1 on the muffler mod. Cheap and easy, and you'll see a bit more power out of the saw for it. Pulls a 28" bar in hardwood quite comfortably with skip or full-comp.

 

[Simonizer]

I got a little something for your 10:19, I would put my new 7900 on it:biggrinbounce2:

A ZX-14 Kawasaki? Jesus they are fast. I had a GSXR-1100 new in 1986 and it was about a 10.70 machine. Fun but very wheelie prone due to the short wheel-base. Great sportbike though.

 

[Simonizer]

Grand Nat's are cool. I would like to have one some day.

I hope the VERT will be a low 10 sec street cruiser when it is done

There is still the occasional GNX for sale but usually around 90K USD. They made 547 of them. Check out youtube to see the 1000+HP GN. Kinda cool.

 

[J.Gordon]

I got a nice shiny new one, I would like to see pics and here info on the pro and cons on the mods. I want to open the muffler maybe a double barrel setup! Who can do the muffler for me? What kind of cost does the muffler mod cost???


Got any pics??


P.S I did search and found some good stuff but i am sure there is more

I didn’t mod my 7900 but it was modded by Ed Heard. I don’t know what a stock 7900 runs like but if it’s anything close to the 7900 EHP, I would be happy.

This saw puts a big smile on me when I fire it up, even with ear plugs and Pelter work tunes. (But it is damn loud!!!)

Pros would be power and very fast.

Cons would be too loud and likes the fuel. (Well worth it in my humble opinion.)

Don’t have any pics of it though.

 

[ericjeeper]

here is the best one I have seen

http://arboristsite.com/attachment.php?attachmentid=12112&d=1082159232
Not mine.. but I did copy it.

 

[blsnelling]

The only ported 7900 I've run was slower than stock. Perhaps not broken in yet, but they don't pick up that much. Mod the muffler and cut wood!

 

[Peacock]

Hey Steve, I had a modded '87 Grand National that LOVED Mustangs and Corvettes. 10.19@141.

I had one too. Just sold mine in the summer. Basically stock, went 12.80 on 15psi. Beat a ton of low 12/high 11 cars with it 'turned up'.

 

[Cut4fun]

The only ported 7900 I've run was slower than stock. Perhaps not broken in yet, but they don't pick up that much. Mod the muffler and cut wood!

Brad I ran Andyshines saw at the gtg that you are talking about and it was way to rich. It wasn't running right at all.
Plus Eric's stock muffler modded only, is one strong stock 7900, it's one of those sleeper keepers.

Also didn't you run my Blue Dolmar at the spring 07 gtg? Sorry if I didnt hand it over for you to take a spin.

spring 07 gtg times Andyshines was 2nd with a crap chain in the gas saws ran.

80cc and down
10" poplar one down one up cut

Kevin 7900 6.87
Andy 7900 7.62
Brad 460 8.82
Jerry 460 9.75

Personally the next 7900 I get will be stock and muffler modded only. Great saws.

 

[davefr]

I got a nice shiny new one, I would like to see pics and here info on the pro and cons on the mods. I want to open the muffler maybe a double barrel setup! Who can do the muffler for me? What kind of cost does the muffler mod cost???


Got any pics??


P.S I did search and found some good stuff but i am sure there is more

A 7900 muffler mod is very easy to do. (Much easier then a 5100 due to the shape of the muffer).

Remove the muffler and gradually open up the crimp on the bottom edge. Start in the middle because that's where it peels easiest and gradually peel open the crimp until you reach each corner on the bottom edge only.

No need to uncrimp any further because now you can slide both halves apart. Squirt some WD40 or oil into each remaining crimp so they slide appart easier. (both side edges and top edge).

Now whack the top half of one half of the muffler with a rubber mallet and it'll gradually slide down the side crimps and seperate. You won't dent the muffler if you go fairly easily.

As for the muffler, I just removed the end piece of the baffle that redirects the exhaust down 90 degrees. I also expanded the exit hole about 50-75% using a Dremel tool. The spark arrester screen will still fit.

Now slide the two halves back together and recrimp the bottom edge with a vise.

Once you reinstall the muffler there will be no evidence that the muffler was ever modded since it sits in a pocket and the lower edge doesn't show.

I should have taken pics but didn't. I'm sure a dual port mod would yield a little more performance but it's alot more involved and not invisible.

 

[blsnelling]

Also didn't you run my Blue Dolmar at the spring 07 gtg? Sorry if I didnt hand it over for you to take a spin.

I don't recall if I ran that saw or not. I do know that I was blown away with Eric's for only having a muffler mod. I guess I'm just gun shy on having a saw ported after what I went through with my 361. I know what it's like to have a ported saw that won't run. That's why I started doing all my own, and I'm glad I learned. It's a LOT cheaper They may not be the fastest in the camp, but they sure run strong.

 

[Andyshine77]

Yes my 7900 was running way rich, and from what I know now, it was most likely running rich at the spring gtg as well. The problem is I was tuning the saw like it was a stock saw, I had to turn the high speed jet in a little more than one full turn to get it to run properly.

I'm going to compare, and time my modded 7900 to my stock one as soon as I can walk without any pain from my fractured ankle.