I have a Dolmar PS510 I can‘t get started. I have 110 psi compression, fresh fuel/oil mix, new plug properly gapped, new fuel and air filters. Carb is rebuilt and pressure tested. When plug is grounded to the saw I get good spark. When I try to start I get nothing. When I try to start with starter fluid or a small amount of gas in the cylinder, I get nothing. Not sure where to go from here. Any suggestions Much appreciated.
Dolmar PS510 won’t start
- Thread starter Ambrosia
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Fatherwheels
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Is there a decomp valve on the saw, does it seal properly.
Does the flywheel turn when you pull the rope, is the key on the shaft ok.
Is the carb set up right, maybe turn in the idle a bit to see if it starts, they won't
start unless the idle is set right,they fire and die again, well unless you have a very
rich supply of fuel getting in there.
Is the plug wet after trying to start, keep the choke on for only two pulls, then off with it,
it may take a little extra pulling but you wont flood it. Is there a primer bulb, pump it until
it is filled with fuel, don't over pump or you will flood the saw.
Does the flywheel turn when you pull the rope, is the key on the shaft ok.
Is the carb set up right, maybe turn in the idle a bit to see if it starts, they won't
start unless the idle is set right,they fire and die again, well unless you have a very
rich supply of fuel getting in there.
Is the plug wet after trying to start, keep the choke on for only two pulls, then off with it,
it may take a little extra pulling but you wont flood it. Is there a primer bulb, pump it until
it is filled with fuel, don't over pump or you will flood the saw.
Thanks for the reply. No decomp valve. No primer bulb. The flywheel turns so I aSumer the key is intact. The carb has a new kit in it, installed properly. And pressure tested. I’ll try turning off the choke after two pulls as you suggested. Not sure why I can’t get it to fire at all with having good spark and fuel in the cylinder.
Fatherwheels
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One easy test, put a little fuel in through the plug hole, no choke at all, and pull until it either fires or not,
if it fires, then its fuel related. I still would turn the idle screw in a few turns, count them so you can return to it if it doesn't help.
Yep, did that already without success. Thanks.
Fatherwheels
Addicted to ArboristSite
Try another new plug, sometimes they are faulty and fire, but won't fire under compression. If still no go,
take out plug and see if it is wet, it should be wet after a session of pulling and failing to start.
No primer bulb can take quite a bit of pulling to get fuel into the system, a wet plug would indicate
fuel is present.
are you sure its not just flooded ?
i usually pull it over a few times with the plug out and the saw upside down, and you will see a mist if its flooded
Hi, you mentioned 110 psi. That’s notably low for a 2 stroke and could be a potential cause of it not running. Ideally it should be around the 150psi mark. It could be your issue.
I’d suggest taking the muffler off and looking into the exhaust port at the piston and report what you see.
Also, do you have any background on the saw? Did it randomly die during a cut and you couldn’t get it started again? Did it work last time you ran it and it’s been a while since it was used last? Where are your screws on the carby set?
We’ll get to the bottom of the issue
I’d suggest taking the muffler off and looking into the exhaust port at the piston and report what you see.
Also, do you have any background on the saw? Did it randomly die during a cut and you couldn’t get it started again? Did it work last time you ran it and it’s been a while since it was used last? Where are your screws on the carby set?
We’ll get to the bottom of the issue
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Try starting it with WOT. Sounds to me like it is flooded. It can be flooded without showing a very wet plug. I had a neighbors saw over a few ago, and everything checked good. So I pulled and pulled and after 40, 50 or more pulls it started and ran good. Neighbor is not very familiar with saws and flooded it. It was the first thing I checked and it looked good but wasn't.
get another compression tester and recheck your compression.....if it comes up 110 again...you need to rebuild your saw. dolly saws are around 190 on the low side and 220 on the high side when new. anything below about 150 and they start getting some funky running/starting problems. if 110 is accurate your starting issue is 100% due to low compression
It’s certainly worth trying again. I’ll look for the mist. Thanks Frank.
I’ll do that, retest the compression. Thanks Ford.
I hadn’t started it for about a year but prior to that had no running problems. The carb has limiter caps so I’m not sure how to answer that question. Also, I didn’t remove those H and L screws while cleaning and rebuilding the carb and I’m not sure if that’s significant. I will take the muffler off and inspect the exhaust port and piston but won’t be able to do this till next week as I’ve gone out of town. Thanks for your help.Hi, you mentioned 110 psi. That’s notably low for a 2 stroke and could be a potential cause of it not running. Ideally it should be around the 150psi mark. It could be your issue.
I’d suggest taking the muffler off and looking into the exhaust port at the piston and report what you see.
Also, do you have any background on the saw? Did it randomly die during a cut and you couldn’t get it started again? Did it work last time you ran it and it’s been a while since it was used last? Where are your screws on the carby set?
We’ll get to the bottom of the issue
Can't really clean a carb properly without removing them.
Pull the limiters, count turns in to seat & then remove screws. Use the straw to spray carb cleaner into screw holes, it should come out the jets. Refit screws & set to factory turns out (usually 1-1.5)
Pull the limiters, count turns in to seat & then remove screws. Use the straw to spray carb cleaner into screw holes, it should come out the jets. Refit screws & set to factory turns out (usually 1-1.5)
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When I first rebuilt my carb, I too didn't remove the H&L Screws. I saw an improvement in operation, but it wasn't complete. I went in and remove the limiter and the screws and the saw ran almost or like new. That likely is not related to your starting problems.
Maybe the muffler outlet is plugged with mud dauber nests. No air out, no air in = no or low compression.
Makes no difference in compression readings.
