Maruyama MCV51

[Simondo]

Well, there must be an issue with 5105 dolmars, if 166 was aware of the fix, no?
Simon, you're a dolmar dealer, and you say you haven't heard of it?
The carb number you posted is different than the one I posted.
So what all carbs are compatible with the 5105?

Im not a Dolmar dealer in the way 166 is but i do have links to one in the UK that i obtain saws from for customers that want them. 166's fix is not one i have come across before due to this not being a issue that i have had on 5105 saws or a commonly known problem here. The Zama DM 20 is the current carb that i know of on the 5105 ...i think the DM 14 was used on the USA saws in the past. I wouldnt know if there was a carb swap to try.

 

[wcorey]

So far I haven't seen this issue with mine but if it happens I'll likely try giving the spring a bit of a stretch. Next thing would be to touch up the needle seat.

It seems doubtful to me that the 15-25 psi needed to pop off past the needle is going to happen under typical circumstances, the tank would likely be bulging noticeably by that point.
The needle not seating properly seems the most likely explanation.

I'd bet the epa would frown on two way tank venting, would then require vapor recovery and such.
It seems most saws I work on don't vent in both directions, a least not enough to prevent the small amount of pressure build up needed to spray gas from an open fuel line.

I can open/close the cap and in a few minutes still have fuel spewing out the line again. No sure whether its vapor expansion due to temperature, agitation or what but it can be pretty persistent.

 

[Greenthorn]

So far I haven't seen this issue with mine but if it happens I'll likely try giving the spring a bit of a stretch. Next thing would be to touch up the needle seat.

It seems doubtful to me that the 15-25 psi needed to pop off past the needle is going to happen under typical circumstances, the tank would likely be bulging noticeably by that point.
The needle not seating properly seems the most likely explanation.

I'd bet the epa would frown on two way tank venting, would then require vapor recovery and such.
It seems most saws I work on don't vent in both directions, a least not enough to prevent the small amount of pressure build up needed to spray gas from an open fuel line.

I can open/close the cap and in a few minutes still have fuel spewing out the line again. No sure whether its vapor expansion due to temperature, agitation or what but it can be pretty persistent.

Thank you, that's what I wanted to hear, in my limited experience I may have only taken off 6 carbs on saws and I just never seen the fuel keep flowing like that, so I am going to assume that's normal.

 

[Simondo]

Thank you, that's what I wanted to hear, in my limited experience I may have only taken off 6 carbs on saws and I just never seen the fuel keep flowing like that, so I am going to assume that's normal.

Any update on your situation with the saw ?

 

[Greenthorn]

Any update on your situation with the saw ?

Yes sir, they both start now after setting for extended period of times.
They have set for 10 days and started first pull on choke this morning.

 

[Simondo]

Yes sir, they both start now after setting for extended period of times.
They have set for 10 days and started first pull on choke this morning.

Excellent ! Thats a average is it ..1 pull till they pop on choke now from cold .

 

[Greenthorn]

Well, they have been setting in an 80 degree garage for the last 10 days, I was going to wait a couple more days to try, but I saw another post about someone having this problem. Started first pull, just blipped the throttle and they kept on running. I saw where ford150 posted about the tank vent might really be the problem, unless I misunderstood?

 

[Simondo]

Well, they have been setting in an 80 degree garage for the last 10 days, I was going to wait a couple more days to try, but I saw another post about someone having this problem. Started first pull, just blipped the throttle and they kept on running. I saw where ford150 posted about the tank vent might really be the problem, unless I misunderstood?

I Feel a tank vent is all about not causing a vac in the tank and would cause fuel starvation by not letting air in (assuming we are dealing with a 1 way vent) therefore not working. I guess there will be a reason behind the thinking , i just haven't worked it out yet.
Anyhow..the main thing is your not getting liquid out the front now and the saw/saws fire up.

 

[Miller Mod Saws]

Paging @Greenthorn

I've been playing with your prob here's what has helped mine the most. Not saying I did it right. The metering spring didn't help very much. Did help but didn't fix it. So here's where I went.

 

[Miller Mod Saws]

I do believe it's just building way to much pressure in the tank. I took the starter off and These four bolts out.

 

[Miller Mod Saws]

That allows you full access to the tank vent

 

[Miller Mod Saws]

Use a small flat tip screw driver and pop that white filter out and this is what you see. The center of that is just rubber. Pull it out with a needle nose pliers.

 

[Miller Mod Saws]

This is what you get. The first one I split with a razor blade. About 3/4 of the way up. Worked good but when rolling the saw around would leak just a tad bit of fuel.

 

[Miller Mod Saws]

The next one which I didn't take a pic of. I just nipped a little bit off the corner with a pair of side cutters. That one worked really nice and didn't leak fuel.

Good luck. Hope this helps. 15 min job and it helped mine a lot.

 

[Miller Mod Saws]

O and a heads up. When I did the first one. When I pulled the tank away. Watch you throttle cable. Mine came out and the throttle wouldn't work right. Easy fix I didn't even have to take the saw back apart. But watch for it.

 

[Jughead]

Thank ya man.mines still giving me fits too.