# [SOLVED] Dolmar 309 concrete cut off saw



## Graham p (Jun 7, 2010)

Hi
I have a Dolmar 309 concrete cut off saw and am looking for some advice, From looking round this looks the best place to get some.
I can only get the saw to run with the choke ¾ on without filter but lacks power, it will not tick over.
Compression is 110psi after several pulls. With muffler removed you can see slight scoring down two sides of cylinder bore. Carb has had a service kit fitted which has made no difference. I have adjusted both carb screws several times which does not improve it. (Could do with knowing for sure what settings should be). I only have a parts manual for this saw, which does not help a lot.I would welcome some experienced advice.


----------



## kjms1 (Jun 4, 2010)

*Re: Dolmar 309 concrete cut off saw*

in choking it you're making it get more fuel but with it 3/4 closed choke your cutting out enough air into it 
Compression checks should only be like 1 or 2 rotations and if a pull gives you 2 or 3 piston strokes 1 pull is more than enough ... plus you need to look and see what the first reading is the first time the piston comes up and compresses the gauge

check fuel line's to see if they almost totally blocked ... check fuel fileter


----------



## Graham p (Jun 7, 2010)

*Re: Dolmar 309 concrete cut off saw*

Hi 
Thanks for the response, I have checked the fuel filter & pipe to the carb. Fuel will run from the pipe quite freely when disconnected from the carb. & the saw is tipped up. Compression tests out at 80psi on the compression stroke, by getting the piston to the bottom of its stroke & giving it a short sharp pull on the pull cord, is this a bit low?


----------



## Graham p (Jun 7, 2010)

*Re: Dolmar 309 concrete cut off saw*

Just a thought, if I pull starter cord slowly so I can see what’s happening for a single compression stroke I get a reading of zero psi


----------



## kjms1 (Jun 4, 2010)

*Re: Dolmar 309 concrete cut off saw*

you will get a real low reading if you go slow ... pull the cord half way up real slow then give it a go
If your getting 80 psi on a single compression stroke that is good 



> Carb has had a service kit fitted which has made no difference.


that doesnt mean **** bro ... its the cleaning of the passage ways that counts ... a few gaskets is going to change how it runs unless the are torn


----------



## Graham p (Jun 7, 2010)

*Re: Dolmar 309 concrete cut off saw*

Sorry for delay doing compression test as sugested getting between 60 & 70 psi


----------



## pat mcgroin (May 1, 2009)

*Re: Dolmar 309 concrete cut off saw*

With the need for 3/4 choke, it souund like the carb primary circuit is fairly plugged up.

Depending on the carb you may be able to pull the bottom of the carb apart and
poke around with a small piece of wire and then a shot of carb ccarb cleaner.
to help clear it.
I often try to use the wire from a loaf of bread.
Melt the plastic off and push it through any metering orfices that you can.

If it has a float be very careful not to bump it while removing it so as to not change the setting.

After reassembly put a generous amount of fuel injector cleaner into the tank and run it.
That will help to clear out more of the varnish.


----------



## kjms1 (Jun 4, 2010)

*Re: Dolmar 309 concrete cut off saw*

I originally said to check the fuel line cause 2 cyl fuel and oil mix when it sits for a while it will cake up and plug the line or even the carb ... Like Pat is saying


----------



## Graham p (Jun 7, 2010)

*Re: Dolmar 309 concrete cut off saw*

When carb was striped down it looked clean without deposits, but I will strip it again & ultrasonic clean it in a bath of teepol at work any other pointers ? It may be a couple of days before I can get back to you. Do you consider compression to be ok ?


----------



## pat mcgroin (May 1, 2009)

*Re: Dolmar 309 concrete cut off saw*

Lets see how that goes..
Be extra careful when reinstalling it to assure that there is no possibility of a vacumn leak
between the carb and its mating surface.


----------



## Graham p (Jun 7, 2010)

*Re: Dolmar 309 concrete cut off saw*

Success. Saw runs & ticks over ok ,could do with a little more power on full revs but suspect this is just a matter of adjusting carb. a little bit better.


----------



## SABL (Jul 4, 2008)

*Re: Dolmar 309 concrete cut off saw*



Graham p said:


> Success. Saw runs & ticks over ok ,could do with a little more power on full revs but suspect this is just a matter of adjusting carb. a little bit better.


Thanks for the return visit!! What was the solution to get you this far??


----------



## Graham p (Jun 7, 2010)

*Re: Dolmar 309 concrete cut off saw*

Cleaning the carb again seems to have been the answer


----------



## Basementgeek (Feb 7, 2005)

*Re: Dolmar 309 concrete cut off saw*

Great news, will mark this post solved.

BG


----------

