The Makita Monster I Think I've Created

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old CB

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Why would anyones not use the decompressor ? It is way easier to pull and a lot less wear on the recoil.
Kash
Some saw mechanic can explain it better than me, but decomps (when used) have been known to cause serious damage to saws. They stick open with carbon or some such. Don't know for sure. I know only that I get along without using them, and have had a good mechanic say that's a good practice.
 

CanadianCarGuy

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Well that would certainly be a bother. In all my searching around for parts for this saw, I did run across info that there had been a recall for the flywheel on certain models of this saw. There had apparently been a couple of reported incidents where the flywheel flew apart. And, of course, my saw serial number fell in that range. Think Makita would still spring for a new flywheel?
I can confirm that!! I had one explode on a brand new ported 7900. Totalled the saw, got shrapnel in my arm and stomach. It was like a grenade went off. Didnt get hurt too bad as flywheel side was away from me. Chunks of flywheel went clear through the case and top cover.
 

dboyd351

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I can confirm that!! I had one explode on a brand new ported 7900. Totalled the saw, got shrapnel in my arm and stomach. It was like a grenade went off. Didnt get hurt too bad as flywheel side was away from me. Chunks of flywheel went clear through the case and top cover.
You should post that on the worst saw mishaps thread
 

ballisticdoughnut

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Well that would certainly be a bother. In all my searching around for parts for this saw, I did run across info that there had been a recall for the flywheel on certain models of this saw. There had apparently been a couple of reported incidents where the flywheel flew apart. And, of course, my saw serial number fell in that range. Think Makita would still spring for a new flywheel?
It would be in Makita's best interest to repair that saw. That's my thoughts anyway. Turns out around 1,300 saws of the 6400 and 7900 variety were involved in the recall, so not that many really. My 6400 is ok thankfully. You may wanna give Makita customer service a call.
 

serdie

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It would be in Makita's best interest to repair that saw. That's my thoughts anyway. Turns out around 1,300 saws of the 6400 and 7900 variety were involved in the recall, so not that many really. My 6400 is ok thankfully. You may wanna give Makita customer service a call.
I always drop started all my saws until I got older and arthritis set in my hands and wrists. It’s a good idea to pull the decomp valve out once a year and clean it it will coke up around the seat and cause problems. I usually order a dozen and put em on the shelf. Don’t like cleaning em.
 

chipper1

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Some saw mechanic can explain it better than me, but decomps (when used) have been known to cause serious damage to saws. They stick open with carbon or some such. Don't know for sure. I know only that I get along without using them, and have had a good mechanic say that's a good practice.
Exactly, use them or don't ever.
If there is carbon on it and someone else uses the de-comp you can drop carbon into the cylinder and put a carbon smug on the piston. Wouldn't want that for a piston picture of a saw for sale, everyone would:crazy2::laughing:. Not a big deal really, but having carbon cause and air leak at the valve, that's reason to avoid using them and I've seen it happen a few times.
 

ballisticdoughnut

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Exactly, use them or don't ever.
If there is carbon on it and someone else uses the de-comp you can drop carbon into the cylinder and put a carbon smug on the piston. Wouldn't want that for a piston picture of a saw for sale, everyone would:crazy2::laughing:. Not a big deal really, but having carbon cause and air leak at the valve, that's reason to avoid using them and I've seen it happen a few times.
I removed the decomp valves on my 026 and 036. the 026 definitely doesn't need it, the 036 could use one but I don't need it so it's been removed. My 7900 has one but I'm considering removing it as well. If you've got your starting technique down you don't really need decomps.
 

rms61moparman

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I bought an 8400 (7900 with 84cc big bore) that was like that. Pulled over fine with decomp but you could NOT pull it over without using the decomp! Sometimes it would pop the decomp out just by the pressure of cranking. Sold it to a neighbor who used it for professional firewood cutting for 5 years. He sold it to an employee who has used it for another 3 years and it STILL won't pull over without the decomp!!!!


Mike
 
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