Makita / Dolmar 6400 Big Bore Upgrade - OEM Kit Number Questions

[Jonny Quest]

Gents:

I have a Dol-Kita 6421 (Home Depot rental fleet). I want to install an OEM Big Bore upgrade kit. I've been searching the internet and there are several OEM numbers out there and I want to make sure that I get the kit that will bolt-up wit minimal mods. Here is what I've found:

038-130-031
038-130-910
038-130-070

It looks like the 031 and the 910 come with a compression release and new cylinder cover. The 070 looks like there it's just a cylinder, piston, wrist pin and clips. Any idea which is which? Will they all fit the 6421 as an upgrade?

Thanks,

JQ

 

[Deleted member 149229]

@fordf150

 

[SOS Ridgerider]

They all fit. It’s all the same kit, but it replaces a few older part numbers. For the 6421 you don’t need the top cover.
You technically only need cylinder, piston, pin and clips, but a new de comp is never a bad idea. @fordf150 will set you up with exactly what you need. Knowledgeable and trustworthy.

 

[AlfA01]

@fordf150

Yep. He's da man!

 

[fl cracker]

This

 

[fordf150]

everything you need except a base gasket is included in the 038130910 kit....all 7900/7910 cylinders are the same now but the 910 kit includes all the extra parts for the same price as just a P&C kit.

 

[Jonny Quest]

Thanks guys, I appreciate the information. I plan on ordering the 038-130-910 kit.

After installation, I plan on re-tuning the high and low needles on the carb -- no big deal. What are some opinions about the heavy-duty air filter kit that is available for these saws?

JQ

 

[AlfA01]

Thanks guys, I appreciate the information. I plan on ordering the 038-130-910 kit.

After installation, I plan on re-tuning the high and low needles on the carb -- no big deal. What are some opinions about the heavy-duty air filter kit that is available for these saws?

JQ

It's the bees knees! Very functional, seals great and looks good too. The kit actually has like three stages of filtration - there is a mesh screen on the housing, the filter itself and the add on filter sleeve.

The only thing you have to make sure of is that the retention clip is always secure (removal and installation for cleaning and maintenance) and possibly add a little epoxy around the base of the filter where the pleats meet the rubber molding top help provide the paper element a little more security.

IMHO, its a well worth the investment. Order with the P&C and you can only tear the saw apart once and have everything done and ready to go. It also has the winter anti-icing doo dad, which may be of importance to you in Utah. Lived there myself for four years (Hill AFB) so I know how the weather can be.

Cheers,

 

[tdiguy]

Not trying to dredge up an old thread, the side decomp cylinder is still available in the 038-130-070 kit. As an FYI to anyone doing some research / searching. Oh and no funny looking exhaust port like the cylinder for the 7910 with the SLR muffler.

 

[asauer]

Not trying to dredge up an old thread, the side decomp cylinder is still available in the 038-130-070 kit. As an FYI to anyone doing some research / searching. Oh and no funny looking exhaust port like the cylinder for the 7910 with the SLR muffler.

Are you saying these are still the original 7900 piston and cylinders?

 

[tdiguy]

From what i received, it is the 7900 Dolmar/7901 Makita parts. The place I ordered them from listed it as the 7901 piston and cylinder kit. I wouldn't say original, but i think they are still making them. I put it on a 2007 Dolmar 6400 and everything fit. My 6400 is the Phase 1 pre/cat muffler, side de-comp version. The exhaust port does not have the step like the 7910 cylinder has for the SLR muffler. At least from the pics i have seen of the 7910 parts.

 

[computeruser]

Decomp on the starter side?

 

[SOS Ridgerider]

From what i received, it is the 7900 Dolmar/7901 Makita parts. The place I ordered them from listed it as the 7901 piston and cylinder kit. I wouldn't say original, but i think they are still making them. I put it on a 2007 Dolmar 6400 and everything fit. My 6400 is the Phase 1 pre/cat muffler, side de-comp version. The exhaust port does not have the step like the 7910 cylinder has for the SLR muffler. At least from the pics i have seen of the 7910 parts.

Very interesting. Would you happen to have a link to where you got it from?

 

[Hulsty]

I bought and had a 7901 P/C OEM delivered last week from sawsagain I think it was

 

[tdiguy]

Decomp on the starter side?

yes. https://sleequipment.com/makita-genuine-part-038-130-070-cylinder-piston-cpl-dcs7901.html It looks like it was drop shipped from the Makita warehouse.

 

[Jonny Quest]

I also got mine at SLE Equipment. This has been a great saw with the new top end.

JQ