Makita 6401 cylinder piston kit?

[kallaste]

I just bought a 6401 from Home depot rentals for $250.00,It was only rented 49 times and seems to run great! I am thinking about putting a 7900 jug and piston on it from Baileys. I have rebuilt many chevy smallblocks, but chainsaws are new to me. Could someone explain the procedure to me? Is it as simple as pulling the carb,jug,wristpin clips,wristpin and removing the piston? Reassemble in the reverse order?

Thanks Steve..

 

[davefr]

I just bought a 6401 from Home depot rentals for $250.00,It was only rented 49 times and seems to run great! I am thinking about putting a 7900 jug and piston on it from Baileys. I have rebuilt many chevy smallblocks, but chainsaws are new to me. Could someone explain the procedure to me? Is it as simple as pulling the carb,jug,wristpin clips,wristpin and removing the piston? Reassemble in the reverse order?

Thanks Steve..

That's basically it. The piston need to be facing the right direction. It should be stamped to show the orientation. Get extra clips because they tend to go flying. You'll need a base gasket and something to compress the rings with. A giant tie wrap works good for ring compression.

It's a good idea to lubricate everything with 2 cycle oil during assembly.

Before you embark on this project make sure the saw works fine as a 6401. While your at it I'd think about replacing other parts like fuel line, impulse hose, boot, filter etc.

If you want a 7900 factory service manual pdf send me a PM.

I'd conclude it's transformation by opening up the muffler. It's very easy to do on a 7900 even though the muffler is crimped.

 

[NPKenny]

If you don't want to go overboard with anything like squish and porting, it is just like you describe. Really, it is a very simple worthwhile upgrade that will take a small portion of an evening. I would really recommend pulling the carb to to eliminate the H screw limiting tab and give it a good cleaning.

Also, as I just learned...make sure you really clean the cylinder and piston prior to assembly and coat the piston, cylinder, and ring with a good dose of 2-stroke oil. Also remember that you will need to run through a bit of a break-in period with the new piston and cylinder to seat the ring, etc.

It's also a good idea to look at your crank and bearings while you have the top-end off.

 

[Freakingstang]

Is it as simple as pulling the carb,jug,wristpin clips,wristpin and removing the piston? Reassemble in the reverse order?

Thanks Steve..

Basically, yes.

Make sure you clean everything very thorough before disassebling it. The crankscase doesn't need anything in there to help the bearings or worse the p/c to get damaged.

They make good runners, used to have a couple of them. I would open the muffler up also, as mentioned already. You will probably have to trim the limiter caps on the carb so it isn't lean after the p/c swap and muffler mod.

Good luck

 

[NPKenny]

Before you embark on this project make sure the saw works fine as a 6401. While your at it I'd think about replacing other parts like fuel line, impulse hose, boot, filter etc.

If you have any question on this...Search under my name for the 6401.

Looks like we had a lot of posting at the same time.

 

[cuttinscott]

http://www.arboristsite.com/pp-classifieds/showproduct.php?product=29

 

[kallaste]

Thanks for the info!! more questions.. help please..

I ran the 6401 on a bunch of live hedge apple tonight. It ran very well. It did have a anti kickback no name chain on it when I got it and even though new it didnt cut like a pro chain.
I also have a Husqvarna 372xp (purchased new 6 months ago) this thing eats wood like a drunken termite even with a 32" bar. But.. we all want more dont we???!!! Question.. Would I be better off having the 372 walkerized with ported muffler and porting and polished cylinders. Or converting the 6401 to a 7900. Or, should I just port the mufflers on the 372 and the 6401 and re-tune the carbs to see what I get? The 372 weights 13.4 lbs and has 5.3 hp which is 2.52 lbs per hp and 6401 weight 13.9 lbs and has 4.7 hp which is 2.95 lbs per hp.

I know it's a personal preference, but what would you all do?

Thanks,

Steve

 

[davefr]

I ran the 6401 on a bunch of live hedge apple tonight. It ran very well. It did have a anti kickback no name chain on it when I got it and even though new it didnt cut like a pro chain.
I also have a Husqvarna 372xp (purchased new 6 months ago) this thing eats wood like a drunken termite even with a 32" bar. But.. we all want more dont we???!!! Question.. Would I be better off having the 372 walkerized with ported muffler and porting and polished cylinders. Or converting the 6401 to a 7900. Or, should I just port the mufflers on the 372 and the 6401 and re-tune the carbs to see what I get? The 372 weights 13.4 lbs and has 5.3 hp which is 2.52 lbs per hp and 6401 weight 13.9 lbs and has 4.7 hp which is 2.95 lbs per hp.

I know it's a personal preference, but what would you all do?

Thanks,

Steve

I'd sink the money into the saw that's in the best overall condition. If it doesn't matter then I'd convert the 6401 into a 7900 and throw the 372XP on Ebay.

However if you suffer from CAS then modify both of them and keep them.

 

[Pablo26]

Bailey's has a nice PDF document with instructions. I think even I might be able to do it.

 

[RiverRat2]

If you don't want to go overboard with anything like squish and porting, it is just like you describe. Really, it is a very simple worthwhile upgrade that will take a small portion of an evening. I would really recommend pulling the carb to to eliminate the H screw limiting tab and give it a good cleaning.

Also, as I just learned...make sure you really clean the cylinder and piston prior to assembly and coat the piston, cylinder, and ring with a good dose of 2-stroke oil. Also remember that you will need to run through a bit of a break-in period with the new piston and cylinder to seat the ring, etc.

It's also a good idea to look at your crank and bearings while you have the top-end off.

You speak like you know a bit about this procedure Kenny????:monkey: :monkey: :monkey:


LOL!!!!!

 

[Sethro]

 

[NPKenny]

You speak like you know a bit about this procedure Kenny????:monkey: :monkey: :monkey:


LOL!!!!!

You can say I have some newly acquired experience with this proceedure.