84 ccm to dolmar 7900

[DOLMARnorway]

can anyone give me a tip on where I can buy 84ccm cylinder set in the best quality to my Dolmar 7900?

 

[plumbcrazyjr]

dont do it. I have yet to see one that is worth the time to put on. Have the stock cylinder ported and never look back!!!!

 

[7hpjim]

I think this is whats your looking for.
Bailey's - NWP Big Bore Cylinder Assembly for Dolmar 7900, Makita 6401, 6421, Solo 681

 

[steve316]

bb dolmar

I bought the big bore kit and was not happy with the quailty and then I bought the new 7900 kit with the new style piston and pin that is about 14 or 15 grams less in weight.the oem kit was better quailty and only about 60.00 more than the bb kit.If you want the new piston and pin for the weight saving it would be less money than bb kit.good luck Steve

 

[ncfarmboy]

Bailey's site sponsor sells NWP brand BBK 84cc kit and OEM 7900 P&C kits. Can't beat Baileys price on the 7900 kit. I just got 2 had to wait a while on the backorder list. Ahlborn sells a BBK kit that's as good as or better than the NWP kit. I just put one (Ahlborn) on one of my Makita/Dolmar 6401 instead of the NWP kit I have. Since I got the 7900 P&C's the NWP BBK is available.
Shep

 

[wendell]

From those that have both the OEM and the 84 BB, the BB makes no more power so it would be a waste of your money.

 

[Andyshine77]

From those that have both the OEM and the 84 BB, the BB makes no more power so it would be a waste of your money.

You're correct most of them run slower than the stock top end. However a few of them did in fact run stronger than stock, but again the quality was sporadic.

 

[Wagnerwerks]

BB kits

Yeah... A lot of the big bore kits I've been looking at have a very dif port configuration than the stock jug/piston. Makes it a big no go for me.

 

[nmurph]

From those that have both the OEM and the 84 BB, the BB makes no more power so it would be a waste of your money.

I have both and for a personal saw, I would go with the Dolmar kit.

You're correct most of them run slower than the stock top end. However a few of them did in fact run stronger than stock, but again the quality was sporadic.

I have had a couple and they were about equal in power, no stronger. I did have to send one back to Bailey's bc of quality issues. I bought one a few weeks back for a HD conversion. I haven't even opened it to see if it is acceptable.

can anyone give me a tip on where I can buy 84ccm cylinder set in the best quality to my Dolmar 7900?

One of my kits from Bailey's has better than 100 hours and is holding up well. I would spend the extra money for the Dolmar kit if it is a saw you intend to keep for personal use.

 

[watsonr]

I also have one with the BB kit and felt it was not as good as OEM. Compression is not where I think it should be... however, the saw does run well with it, just maybe not as fast. It is turning 12,800 and maybe after some run time the compression will come up. It only has about 1 tank through it so far.... just lots of other saws to run and really need to force myself to run it more.

I do think it has more torque than stock.

 

[user 53634]

Not what I wanted to hear

I bought a used 6401 yesterday just to install this modification and end up with a 7900 so I can run a bigger bar. $121 with the ring kit from baileys. I went with them because they said they would warranty it if it craps out.

So is the 7900 more powerful than the 6400 with the bigger cylinder?

I have 165 compression on the stock cylinder and dont expect that to be much higher with the replacement.

Does anyone have a good story to tell that involves the bigger cylinder and a 24 inch bar combination?:msp_ohmy:

View attachment 220838

 

[Jtheo]

I have had a BB Makita and a stock 7900.

In my opinion the 7900 with the Mahle piston and cylinder makes more power and cuts faster.

A stock 7900 is a hard act to follow, unless you want to port the Mahle cylinder.

 

[Logger4Life]

I also have had both and I also feel the OEM kits are a better way to go but I also have a flip side to this story . I got a BB kit from MCW on here and set the squish to about .021 and did a little port work and used Caber rings plus the oem C-clips and that saw pulled like a freight train just dog it in and hang on and I only had about $325 in the whole saw HD filter kit and all turned out very nice I wish that I wouldn't have gotten rid of it I now have 2 ported 7900's and they don't have the torque that the BB kit had. I had 185psi cold and that wasn't even broken in yet. So I don't know for sure what to say that was just one kind of kit. Not Bailey's though I would talk to MCW .

 

[wendell]

I bought a used 6401 yesterday just to install this modification and end up with a 7900 so I can run a bigger bar. $121 with the ring kit from baileys. I went with them because they said they would warranty it if it craps out.

So is the 7900 more powerful than the 6400 with the bigger cylinder?

I have 165 compression on the stock cylinder and dont expect that to be much higher with the replacement.

Does anyone have a good story to tell that involves the bigger cylinder and a 24 inch bar combination?:msp_ohmy:

View attachment 220838

Yes, the 79 cc saw is more powerful than the 64 cc one.

And it will handle a 24" bar with ease.

 

[MMG]

6401 with 85cc BB

Just bought this off E-Bay.

Can't wait until it gets here.View attachment 223346