Dolmar 5105 warm start question

[Jeff Lary]

Last winter I bought a new 5105 I had a rough go of it in the beginning,.. it did not start well. I have since made up my mind that based on what I have read here I may have been flooding it. I have now figured out how to start it and how closely I have to listen for the first pop. 2 or 3 pulls on choke sometimes one pull gets the first pop. Then choke off starts on first of second pull.

My question is after I run the saw 10-15 minutes and shut it off why does it have to be choked to re-start 15 minutes later? I have tried the choke on then off so as to set the throttle to high idle but that does not work either. Seems to me like 15 minuets and sometimes even less between starts should not require a choking to get it to start back up what do you think?

 

[Deleted member 149229]

@cuinrearview

 

[cuinrearview]

Probably not drawing enough fuel without the choke. I've heard tell of incorrect metering lever height on these. I've also heard of tank vent problems. Before you attempt a hot start try cracking the fuel cap and re-tightening. See if that makes a difference. I haven't experienced either issue but that's what the internet says...

 

[J.W Younger]

Probably not drawing enough fuel without the choke. I've heard tell of incorrect metering lever height on these. I've also heard of tank vent problems. Before you attempt a hot start try cracking the fuel cap and re-tightening. See if that makes a difference. I haven't experienced either issue but that's what the internet says...

You would think a little positive pressure in the tank would lessen the need for choking unless you're thinking there's a vacuum in the tank from the one way check valve not letting air in.

 

[cuinrearview]

You would think a little positive pressure in the tank would lessen the need for choking unless you're thinking there's a vacuum in the tank from the one way check valve not letting air in.

I'm hazy on the details, since I never had issue I usually just skim over things. I probably shouldn't give advice. All I remember is tank vent and metering lever. I think a lot of the "issues" with these saws were blown out of proportion. I only ever had two saws with one of the "common issues" that were thrown around and both were from a poorly performed repair.

 

[J.W Younger]

I'm hazy on the details, since I never had issue I usually just skim over things. I probably shouldn't give advice. All I remember is tank vent and metering lever. I think a lot of the "issues" with these saws were blown out of proportion. I only ever had two saws with one of the "common issues" that were thrown around and both were from a poorly performed repair.

I think they're a pretty good saw, mine has been. We're bad about over hyping things in here.

 

[Huskitoter]

Have you tried adjusting the low mixture a little richer? I have no experience with them and just throwing out an idea.

 

[Jeff Lary]

Fist off thanks for the reply's, I have been in the back garden cleaning up for winter I just came in for lunch. I have opened up the Low screw a fraction maybe it needs a little more. I can tell you that the settings are very sensitive on this saw. I will try the open the tank next time. I agree pressure in the tank should keep fuel pushed up to the carb and start easier. If on the other hand if there was a vacuum in the tank maybe that would draw fuel away? We tend to think serious issues but I bet it is something pretty simple. I should add I don't think it has ever started right since new comparing what I have read here to my own experiences.

 

[J.W Younger]

Fist off thanks for the reply's, I have been in the back garden cleaning up for winter I just came in for lunch. I have opened up the Low screw a fraction maybe it needs a little more. I can tell you that the settings are very sensitive on this saw. I will try the open the tank next time. I agree pressure in the tank should keep fuel pushed up to the carb and start easier. If on the other hand if there was a vacuum in the tank maybe that would draw fuel away? We tend to think serious issues but I bet it is something pretty simple. I should add I don't think it has ever started right since new comparing what I have read here to my own experiences.

I was gonna ask you if this was a new problem.
Your saw is too new for this to be an issue yet but from time to time you might wanna clean the dust off the tank vent dust filter.
It's between the fuel cap and the starter housing and easy to reach with a paint brush.

 

[Ronaldo]

Mine definitely had a tank vent issue that would flood the saw sometimes (never even heard the pop). Now that the vent is fixed it starts like any of my others. Easiest starting saw I own, probably.

Sent from my SM-G930VL using Tapatalk

 

[Brent Nowell]

Hot starts are tricky cause sometimes depending on design fuel will boil in the carb. Just a theory but it is possible this is the case and pulling the choke overcomes the heat causing the fuel to boil.

 

[Jeff Lary]

JW, I will check that out thanks
Ronaldo, what was the issue?
Brent, I will keep that in mind

 

[Brent Nowell]

I meant to say pulling the choke allows more cooler fuel to overcome the heat

 

[Ronaldo]

JW, I will check that out thanks
Ronaldo, what was the issue?
Brent, I will keep that in mind

The little tank vent doesn't vent out well enough, would build up pressure in tank and flood carb. Pull the little white filter in first photo and trim a tiny bit off the corner of the red vent(sitting on gas cap) in second photo. My saw works great now.

Sent from my SM-G930VL using Tapatalk

 

[J.W Younger]

JW, I will check that out thanks
Ronaldo, what was the issue?
Brent, I will keep that in mind

I suspect what will be the most likely thing to fix your problem will be to fatten your low speed circuit..Like you said, on this saw a little can go a long ways. If it was set rich on the high side it may need some leaning afterwards but probably not.
Also make sure your spark plug is gapped right...0.20 and maybe try a different one if the problem continues.

 

[Jeff Lary]

all good things to try for sure. On a cold start it can be pretty impressive. But run it 10 minutes and try to restart it 10 - 15 min later and not so much.

 

[J.W Younger]

all good things to try for sure. On a cold start it can be pretty impressive. But run it 10 minutes and try to restart it 10 - 15 min later and not so much.

If it's an excessive pressure build up that should be pretty easy to run down by laying it on its side and loosen the fuel cap as soon as you shut it off...for sure you need to fasten it before testing the restart 15 min later though.
Also make sure that little slider door in the top cover is set with no opening for exhaust heat to get in.

 

[Jeff Lary]

that door is open I think? I have to look I opened it last winter it was way below zero the week I got it. The first day I used it, it was -17*. I am pretty sure I opened it up cause of the cold weather I think.

 

[J.W Younger]

that door is open I think? I have to look I opened it last winter it was way below zero the week I got it. The first day I used it, it was -17*. I am pretty sure I opened it up cause of the cold weather I think.

Not good...the deflector has an opening in back that will put a lot of heat on the carb.

 

[Jeff Lary]

yea I will have to look at it. I have deflector doors on my old Partners and I don't think it ever caused any issues.