Dolmar 8400 big bore vs Husky 390xp race

[someguy2800]

Hi all,

I have a big white oak about 30" diameter at the base die on my property this summer. In order to fell it I was going to need to drop it across my neighbors property line into his yard. He also burns wood so I called him yesterday and asked if he wanted to help cut it and we would split the wood 50/50 so he came over after work and we cut it. He has a factory stock Husqvarna 390xp he bought new about 3 years ago and I have an old home depot Makita 6400 rental saw that I put a 84cc big bore kit and ported. We were both impressed with how fast these two saws cut so we decided to do a head to head race and see. We set up on opposite sides from each other about 10 feet up the stump where it was about 20"x24" thick and counted off. He finished and I still had 3 inches left. I would say the husky was a good 10% faster.

As I said his saw is a stock 390 husky with a 22" bar. My makita had a 20" bar on it. It has a 84cc big bore piston from ebay and I did a mild port job on it when I built it and opened up the muffler just a tiny bit. My chain was getting pretty dull at the time from all the dirt in the bark but his was probably about the same. The only thing I did on the muffler on mine was to open the outlet about 50% and take the screen off. The compression is stock and it still has a gasket under the cylinder so compression is pretty low.

Just wanted to share the info. Pictures of my porting below

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after



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after



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stock cylinder vs big bore

 

[someguy2800]

Anyone else here have one of these kits ported?

 

[roy wilson]

i have the makits 6400 and got the hyway 84cc cyl kit , and the OEM HD air filter kit did some woods porting to it and gutted the muffler and base gasket delete and used 1184 and its a beast , but the carb is not perfect , sometimes stalls out of a cut and tough to start so will try and get a better bigger carb but seems to be hard to find a good fit with bigger setup

 

[ncfarmboy]

i have the makits 6400 and got the hyway 84cc cyl kit , and the OEM HD air filter kit did some woods porting to it and gutted the muffler and base gasket delete and used 1184 and its a beast , but the carb is not perfect , sometimes stalls out of a cut and tough to start so will try and get a better bigger carb but seems to be hard to find a good fit with bigger setup

Walbro HD-12 is bigger and a direct swap. I used the HD-12 on all 4 of mine. 7900, 2-6401BBK and 681 Solo. Could send your carb to @Poleman he modifys the Zama. All reports are outstanding on his carb. work.
Shep

 

[smokey7]

I really really want a saw based on this chassis really bad. I also want a 6100 bad.

 

[ammoaddict]

I bought a Dolmar 6100 last year. I haven't used it much yet but it is a beast. Easiest saw to crank that I have ever had as long as you don't drop start it. Which is what I have always done. It doesn't work well with the spring assisted starter. If you sit in down or hold it between your legs and pull it over slowly, it fires right up. I like it a lot but if I had a do over, I would have bought a 562xp.

I really really want a saw based on this chassis really bad. I also want a 6100 bad.

Sent from my Moto G (4) using Tapatalk

 

[smokey7]

See im the opposite. I want nothing to do with autotune. Ive seen too many guys helpless in the woods. The saw wont idle or boggs. When if it had carb screws it would get a adjusted and run fine. These poor guys gotta get em scanned and all this crap expensive parts to chamge. Next thing they know they got a $250 bill at the dealer for what couldve tuned out on a reg saw. When they run right my god they run but when they dont your head arm and wallet hurts bad.