Hard starting Dolmar 7900

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Banshee

Addicted to ArboristSite
Joined
Apr 10, 2008
Messages
1,584
Reaction score
148
Location
Indiana
I love this saw when it's running, but it's the hardest starting saw I've ever owned.
It's always been hard to start then one day it wouldn't start for nothing. I took it to the shop and they replace the spark plug and a welch plug (what ever that is) and they did some carb work to it.
I get it home and it still won't start.
What am I missing? Are Dolmars just hard to start? What's the trick?
Someone clue me in before I pitch this saw over the hill.
 
Low compression, or its to lean.. Tuning, or vacum leak. leaking fuel line, or bad seal. compresion test, and vac/preasure test. If the saw is under warrenty, make your dealer check it out better.
 
The Dolmar PS7900 is a real easy to start saw the only saw that really started easier was the 120si with the injection start carb. Sounds like it is way out of tune, how old is it? what shape is the fuel filter in? You do have a NGK BPMR7A plug in it right?




Scott
 
I brought it back to the shop yesterday. They started it, took them a little bit. They said I flooded it.
So today I went to start it. Check the kill switch, pulled the choke out, pushed in the decomp, and made sure my first pull was for all glory. And to my surprise it hit, so I pushed in the choke and made another hard pull and it started right up.
I has to be me. I just need to run the saw more and just learn the saw.
I did some noodling with it and like it said I love this saw when it's running and today I love it. Tomorrow might be a different story.
Thanks everyone for the replies.

cuttinscott, I don't know how old the saw is. It does have the orange top it that helps.
 
The orange top 7900 are from earlier production runs, but there's nothing wrong with them. The newer black top 7900's have a few minor upgrades, but that's about it.

If the saw starts like you described, I'm pretty sure you just needed to learn how to start a 2cycle engine properly, it's very easy when you get the hang of it.

:cheers: Andy.
 
The new Makita (Dolmar)6401 intitially wouldnt start for me. Like the previous post mentioned, the "stop" switch is reversed from my Husky. Figured it out pretty fast though:dizzy: .
 
Dolmar 7900 Won't Start

It usually starts right up but tonight it did not. I smell gasoline. Any ideas? Try to find a Dolmar Dealer in Western PA - forget it. Gonna try a new plug tomorrow as soon as I find where to get one.
 
If you smell gasoline it is probably flooded?

You need to go through the basics.

Pop off the cover and look for gas leaks? Tank vent? carb? Fuel line?

Take out the spark plug. Is it wet or dry?

Pull the engine through with the plug out and the wire connected and see if the plug fires?

I had a Homelite do this last week and the regulator diaphragm in the carb was stiff and the carb was flooding the engine. After fixing the carb, it took a while to clear the engine out.
 
If you smell gasoline it is probably flooded?

You need to go through the basics.

Pop off the cover and look for gas leaks? Tank vent? carb? Fuel line?

Take out the spark plug. Is it wet or dry?

Pull the engine through with the plug out and the wire connected and see if the plug fires?

I had a Homelite do this last week and the regulator diaphragm in the carb was stiff and the carb was flooding the engine. After fixing the carb, it took a while to clear the engine out.


Thanks.
Did that and it started. Looked like it was running on cuban tobacco at first but after the smoke cleared the rpms came back. Appreciate the comeback.:clap:
 
Are you catching the first cough (when it just fires a couple times), and taking the choke off? decomp in again, pull again. should go. If you miss the first cough and pull more with choke on, it floods easily.
 
My 7900 starts easily when cold...usually on the first or second pull. If I run it out of gas, it refuses to hit a lick until it cools off. Also, and this seems kind of strange, if I start it hot and let it die...it acts as though it runs out of gas...it won't start no matter how many times you pull it. When it's running, it runs great. I am not a chain saw mechanic...just know the basics, but it's really frustrating. It's a firewood saw so it isn't like I'm putting a lot of hours on it.
 
My 7900 starts easily when cold...usually on the first or second pull. If I run it out of gas, it refuses to hit a lick until it cools off. Also, and this seems kind of strange, if I start it hot and let it die...it acts as though it runs out of gas...it won't start no matter how many times you pull it. When it's running, it runs great. I am not a chain saw mechanic...just know the basics, but it's really frustrating. It's a firewood saw so it isn't like I'm putting a lot of hours on it.
I had 2 7900s that did the same thing they were both 2 months old when thestarted acting up. my dealer and i tryed everything to make them work right. I finnaly fixed them both by trading them on 2 new husky 390s.
 
When my BB 6401 is started warm, you have to use the choke until it hits then take the choke off and it runs fine.
 
I brought it back to the shop yesterday. They started it, took them a little bit. They said I flooded it.
So today I went to start it. Check the kill switch, pulled the choke out, pushed in the decomp, and made sure my first pull was for all glory. And to my surprise it hit, so I pushed in the choke and made another hard pull and it started right up.
I has to be me. I just need to run the saw more and just learn the saw.
I did some noodling with it and like it said I love this saw when it's running and today I love it. Tomorrow might be a different story.
Thanks everyone for the replies.

cuttinscott, I don't know how old the saw is. It does have the orange top it that helps.

I dont see how taking compression away from a cold saw will make it start better!
 
Back
Top