Dolmar 5105 easy start to hard start?

[DOL51CUTIT]

My Dolmar 5105 went from super easy start to sometimes easy and sometimes very hard.
I use shell v power 91 non ethanol in all my small engines, with a 40 to 1 mix, in the chain saw.
I have even tried the over priced pre mix, just to see if it was a fuel problem. I always run it dry when done.
I've blocked about 35 cords in total in the last 2.5 years. And cut down a few nuisance trees.
Easy or hard starting, when it fires it runs great, and re starts easy, it is just frustrating when it takes 20 mins to get it going sometimes.
I have replaced plugs and keep the plug clean.
Mine does not have the epoxy carb.
Any ideas would be appreciated.

 

[holeycow]

Have you tried opening the lo screw a hair?

I always fill to the top prior to storage. With non-ethanol premium and fuel stabilizer. Works for me.

the 5105 is not the best cold starter, unlike its little brother, the 420. The ez starts do not feel the same at all. Once I learned how to actually use the 5105's ez start properly cold starts became easy.

I'd open the lo screw an eighth to start with.

it's colder out, air is denser, you need more fuel all over..

I have a 20 year old plug in one of my jonny 590's. It started with only a few pulls yesterday after sitting for a month or two.

 

[cuinrearview]

A few folks have solved issues with these by trimming the duck bill valve in the fuel vent.

 

[holeycow]

Weird. Mine just started in one pull after sitting for months. I just topped it up with fuel and gave it a tug while exiting the shop and it was running. Huh. It's never started THAT easily before.

ps, mine tends to flood very easily. I usually give it a couple of pulls with no choke. Sometimes it fires, sometimes not. This time it fired and ran with no choke. It's "tuned" way rich at the moment ( early spring settings ).

 

[2stroker]

Mine seems to be hit or miss. Sometimes it's the easiest starting saw I've ever owned and other times it's a bugger. Is there a proper procedure for starting this?
Also weird the off switch/lever was working like a momentary off switch now sometimes but not all the time which can lead to flooding on restart.
All saws have their unique traits!
2stroker

 

[JimmyT]

Its got to be carburetor or ignition. If your saw is 5 years or older rebuild the carb and use a OEM Zama GND-27 kit. Most likely your fuel pump diaphragm has stretched.
[/QUOTE]

 

[r black]

these saws as well as most Dol/kita saws are great and ...a bit more sensitive to flooding ......easy with that choke lever ...

 

[holeycow]

The 420 is the easiest starting machine of all time. The 5105; not as much.

 

[DOL51CUTIT]

Interesting. A couple said to try without choke first. Am I correct?
I want to correct my statement of 35 cords. I had help it was more like 20 cords.
I think the carb is ok, other than maybe adjusting a bit.
As I mentioned gas storage is dry, and I always use Shell v power non ethanol 91 octane.
I bought the saw, with a couple others the same a couple years ago.
The other 2 which I gave to 2 neighbors start fine year round.
This one turned finicky this last June in warm weather. Some times 1 pull with choke on and 1-2 pulls no choke.
Other times,,, pull and pull, check the plug, sometimes wet sometimes not, and pull some more.
When it starts and warmed up, it re starts in 1 pull normally.
I can't remember the rev limit, 13,400 I think. I would need to pull my file and look, but I have it set about 300 rpms of the limit.
Not in the cut!
I am out of warranty now and have the less restrictive 5100 exhaust can. Would putting it on help?
Any tips on readjusting the carb if I do?
I also have both the flocked and screen air filter, and have tried both for starting.

 

[cuinrearview]

A carb kit for one of these is $6 in @Definitive Dave 's ebay store. You might have a stiff diaphragm or a plugged fuel screen. For how cheap they are I'd pick one up. By the time you pull the carb and take it apart it's cheap insurance.

 

[DOL51CUTIT]

cuinrearview. I'm going to try the duck bill first. If I store after running, with fuel cap loosened slightly. Then tighten just before starting would that possibly diagnose that issue? I ran the saw for a few hours last week, and am going out again in a couple days. I can loosen the cap a bit. or get it fired this am and then loosen the cap a bit after running it?
I will get a carb kit to have in the tool box for when needed now or later.

 

[cuinrearview]

I'm not sure if messing with the cap would help.

 

[DOL51CUTIT]

heated or cold shop 1 pull start holeycow?

 

[DOL51CUTIT]

I'll try it, thanks cu

 

[holeycow]

It was about 5C at the time. My shop heat is on and off through the winter. The slab isn't even cooled down yet. That takes until about mid December, so it takes very little heat to keep it comfortable at this point.

you don't want to run the cat in the muffler. The saw runs way hot with that in there. Quite a bit hotter than my other used-to-be-cat saws I think.

 

[DOL51CUTIT]

Ya I'll pull the cat muffler. I bought the 5100 muffler to put in after warranty.
Any carb adjustments needed?

 

[holeycow]

Probably

 

[Fatherwheels]

A carb kit for one of these is $6 in @Definitive Dave 's ebay store. You might have a stiff diaphragm or a plugged fuel screen. For how cheap they are I'd pick one up. By the time you pull the carb and take it apart it's cheap insurance.

Very good idea, cheap and simple too, and for those who do not know, Makita who own Dolmar too
have decided to dump us all and stop manufacturing Gas / Petrol Chainsaws from 2022,
so get your parts with you can, I really like Makita saws, but my next will be Echo as a result of being dumped.

 

[Fatherwheels]

Ya I'll pull the cat muffler. I bought the 5100 muffler to put in after warranty.
Any carb adjustments needed?

Make sure the spark screen is clean, that alone will make a saw a bear to start.
If your keeping the Makita, get all the parts you need soon, as Makita who own Dolmar too
are stopping production of Gas / Petrol saws from 2022, and am a fan of their saws, still have Two,
but not buying any more for above reason.
http://chainsawrepair.createaforum.com/dolmar/makita-dolmar-gas-to-end/

 

[cuinrearview]

Very good idea, cheap and simple too, and for those who do not know, Makita who own Dolmar too
have decided to dump us all and stop manufacturing Gas / Petrol Chainsaws from 2022,
so get your parts with you can, I really like Makita saws, but my next will be Echo as a result of being dumped.

Pretty sure I'm set on spares, for this series at least. I imagine there are enough spares in the system that even if they stop supporting existing equipment next year(which would be unheard of) we'll be set for a long while.