Discussion in 'Chainsaw' started by Mastermind, Jan 16, 2012.
They are probably the fastest saw in their size range......
Damn strait! Stock out of the box these are potent saws. Ported they are even better, obviously!
My 7900 has sure impressed me, I was just wondering how well they take to being ported.
BTW, your Makita is on the way. Hopefully you get some use out of it.
I have a 6401 hanging on the rack here.......someday I'll play with it.
Thawt U No Like The Udder Jermin Sawz?
Dis Mean U Due My 7900 ?
I hate Zama carbs.......Dolmars are fine saws.....
yeah the Zama's pretty much suck
I know I could search, but I'm gonna be lazy and just ask. So.... what's the deal with the Zama carbs? and can you swap them with some other carb without a bunch of custom fabrication? Thanks
The 7900 will accept a Walbro from a 372 with no mods needed I believe.
I happen to have some 372 parts...
And a 7900...
And an appointment with Mastermind... So, what am I missing?
I'm working on fixing the pics in this thread....
Someday my 7900 will make the trip. For now I'm happy with the way it runs stock.
Good God Im gonna need to get another one. .
Got the wheels turning..... starting to think about that brand new 6400 Dex is offering.
Clint- they are the King of the 70cc range. At 79cc, Id have to group them in the 80cc range though- and I think they hold their own pretty well in that class too. Many have considered the 064 to have had the best power to weight ratio in the past, that was until the 7900 came out. It is the reigning "power to weight" king.
Time money and patience,,, oh and 7900 are great saws,,, Zama carbs are not the best
Yes on all counts!!!
Would swapping the carbs out cure the hot start flooding issues? My 7300 is awful that way
Lean issues are what I see mostly from the Zamas that I have issues with. Heck.....not all of them are any trouble either.
All the Zama carbs I've looked at all have the same jetting - two .25mm jets. The jets can be drilled and the flow increased considerably. When a Zama is used on a bigger engine, they need a lot more flow. I've also tried blocking the auxiliary jet on a Zama and just used a drilled idle jet and with a stronger metering spring it may turn out to be an even better approach.
I'm just starting on modding the HDs. They are a bit more difficult to mod as you have to pull the welsh plug and redrill the air bleed/transition holes (and drilling the body of the carb is permanent, you can't replace the jet like on the Zama if you go too far). Since the HD-12 seems to be a popular carb, it would be great to find out what size holes are used on the carb body, that way someone could drill their existing carb to the HD-12 specs. Although, the HD-12 was used on a 71cc engine, so even the HD-12 might benefit from a bit of tweaking to use on a 79cc engine.
Separate names with a comma.