Breakin' her in

[Marvinlee]

Funky carburetor on 5100S

I took a look at the carburetor. I didn't see anything obviously odd. It has two fuel needles, a metal body, and an idle speed control. What do you see funky about it, Andyshine77? I couldn't see the manufacturer's name, so don't know who makes the carburetor, or what model it is.

 

[mini kahuna]

mine just looks like a run of the mill Zama.

 

[Andyshine77]

The carburetor is in fact a Zama. From what I know it is supposed to compensate for a dirty filter, I think this has something to do with the hole on the top of the carb and the hole on the bottom of the air filter. I don't know this as fact, it's just a thought.

I find It's somewhat odd that any time someone has something negative to say about the 5100 people start getting defensive.

Well have a good one Andy.

 

[DOLMARatOs]

The carburetor is in fact a Zama. From what I know it is supposed to compensate for a dirty filter, I think this has something to do with the hole on the top of the carb and the hole on the bottom of the air filter. I don't this for fact it's just a thought.

I find It's somewhat odd that any time someone has something negative to say about the 5100 people start getting defensive.

Well have a good one Andy.

Andy. You're exactly right. The port is there to help the carburetor meter itself based on the aurflow through the filter. EPA stuff mostly but it does stop the saw from getting rich and pooching out.

I think the issue isn't that someone is saying something negative about a 5100 or any Dolmar saw. It's that when someone has an issue with a Dolmar, they tend to belittle the company as a newcomer and of such poor quality etc. that die-hard Dolmar guys get a bit upset about. Let's remember that Dolmar invented the Gas Chainsaw. They may not be the biggest and have had some ups and downs over the years. Without Emil Lerp, we'd all be swinging axes and cross-cut saws. YAY!

 

[Andyshine77]

DOLMARatOs You make some very good points. Your right I don't like it when people belittle a company just because they like another brand and only that brand.

However I also dislike it when people praise a brand because of brand loyalty, and support it without any constructive criticism.

Andy.

 

[Freakingstang]

I had problems with my 5100 when it was brand new out of the box..flooded it before I heard the "pop"


Many of the Dolmar 5100's and 7900's I have seen and heard local dealers talked about the carbs being set really rich from the factory. After I leaned out the low speed jet, mine fires on the first pull (with choke), starts on the 2nd pull (w/o choke).

I had a hanging idle as I call it....took a while to come down from the revs after a cut. The top end needed a tad adjustment to the richer side. It got predominantly less over many tanks. After having it almost a year, it idles down like any other saw. This saw seemed to take a lot longer to break in than most others...probably 15-20 tanks before the power came up and the hanging idle disappeared

I will say the carb is really sensitive to temperature and humidity, I am constantly adjusting mine... With that said, make sure the thing is good and warm before you go adjusting...


As much as I love my 5100, the mis matched cover is present on mine..I thought maybe it was just mine as it was made in 05....figured they would have fixed it by now.....

Either way, the cover doesn't bother me enough to take it back...I love this little screamer.

 

[John Ellison]

My 5100 also has the handle/cover gap. It glared at me when I first saw it but then quickly forgot about it and had not thought about it until now.
Mine also idled down slow, but it was a hangup or rub in the trigger assembly. I managed to break a spring fiddling with it. My clumsyness. It idles down normal now.
What bugs me is the trigger is two stage (like a military rifle) and has slack in the initial pull. This wastes time:biggrinbounce2: so I thought that the slack could be taken up by twisting the throttle cable. Wrong. It is a hard layed cable and it did not take to twisting. So now I am figuring that when I put the new throttle cable in, something can be epoxyed in underneath the trigger to take up the dead slack.
Not having any experience with other saws this size I cant compare anything, but will say it runs like a scalded dog. Starts easy but does take an extra long time to completly warm up.
Also I will say that almost all of the new saws that I have bought had some kind of minor glitches show up when first starting to use them. Guess you just have to judge them by what you end up with and what you can put up with. To me the two things that matter most, power and smoothness,are top notch on this saw.

 

[Marvinlee]

John, I also wanted to remove most of the throttle cable slack, but with no success thus far. My next move will be to try to find a little "C" washer that I can slip in between the throttle-control end of the cable and the holding device. If I can't find the washer, I might cut a slot in a small flat washer and try it. If it fits, I can then squeeze the washer with needle nose pliers to close the washer slot. The cable slack is not a major point for me, but rather something to experiment with for a bit of added refinement to a fine saw. I did put just one tiny drop of oil on the cable where it runs over the plastic cable guide at the carburetor. It seemed to make the throttle pull a bit easier.

Andy, thanks for enlightening me on the carburetor. It was new information to me.

 

[DOLMARatOs]

Fluid Film on the cable and trigger assembly makes it feel much smoother. A very small split-lock washer might be the idea to take up some space.

BUT!!!!!.....Remember that the engine and carburetor are one unit that is mounted to the handle assmebly (second unit) via isolation shock absorbers that FLEX. When the saw is pulling hard in the timber both directions this set-up flexes. A LOT. Try moving the motor forwards while holding the handle on the bench. Imagine the forces exerted while cutting. If you take up ALL the slack when the unit is sitting still, you could break the cable or damage the assembly.

 

[Marvinlee]

Thanks, DOLMARatOs for the cable slack warning. I'll pay attention!

The Dolmar site parts list has not downloaded for me. I keep getting a "corrupted file" advisory. Is that just my computer, or are others having problems downloading the parts list?

 

[DOLMARatOs]

Try this:

Go to www.mwe.net then on the top right it says "PARTS LOOK-UP" click that and scroll down to dolmar, click that, scroll down to your model equipment and see how it opens. Otherwise go to Adobe's web site and see if they have updates for your version or download the newest version of Adobe.

 

[Marvinlee]

Thanks. www.mwe.net worked great and I now have the parts list.

I noticed today that the slow return to idle is not consistent. Sometimes it will drop right back and at other times it keeps idling fast enough to keep the clutch engaged. Rather than slow down the idle speed and then have it sometimes stall, I plan to keep using the saw cautiously and see if further use corrects the problem.

 

[Andyshine77]

Marvinlee try holding the saw on it's side for about ten seconds than turn the saw upright. If it's anything like the saws I have ran, it should rev up a bit on it's side, than almost stall when you turn it upright.

 

[Lakeside53]

That usually means it's idling too rich, and pooling... or bad seals which I doubt in these cases.

 

[Andyshine77]

That's true, but if you lean the carb up at all, the saws would idle much to fast for far to long after making a cut.

 

[Lakeside53]

Then it's a design issue... I hate saws that run on, and even more so, those that chug or quit when you change attitude (the saw). On Stihl's it's usually just a matter of just balancing L and LA... assuming nothing else is wrong, and the piston skirt is in decent shape.

 

[Andyshine77]

I believe it is a design issue.

 

[B_Turner]

Marvinlee try holding the saw on it's side for about ten seconds than turn the saw upright. If it's anything like the saws I have ran, it should rev up a bit on it's side, than almost stall when you turn it upright.

Andyshine, do you mean hold the saw on its side at idle or throttle? ANd then turn upright with no change to the throttle?

I've not felled with the saw, so typically I've used it to cut vertical so far.

 

[Lakeside53]

At idle...

 

[B_Turner]

Went out to the shed, grabbed the 5100 (about 4 - 5 tanks through it so far).

Warmed it up a few minutes and then held it on it's right side for 10 to 15 seconds at idle, then rotated it to the usual vertical for a while and back and forth for 10 to 15 seconds each position.

I may not be duplicating the correct conditions, but idle seemed reasonably steady. Note I did set my idle down a quite a bit from where it came set to try to help the slow return to idle thing (but still idling around 2500+ according to my tach).

That doesn't mean it won't do it under different conditions, but I haven't noticed it yet.

I do notice that I run it WOT no load sometimes after a second or two of running steady it sometimes will instantly jump up over 1000k (still within spec). Runs pretty good and great upward acceleration so I am putting another tank or two through it before I more finely tune it. Because the high rpm seems to be so variable for now, session to session.

I am running 93 oct w/stihl dino.