Dolmar 510 woes

[David Young]

I bought a Dolmar 510, when I bought it I was told it will not start because it floods itself out.

I have rebuilt the carb and swapped it with a known good carb from a 5105

I always have plenty of spark, I also tried a new plug, checked the flywheel key, set the coil gap. I also swapped a coil from a 5105.

The piston had a scratch in it. I tore it down cleaned the piston, put a 5100 jug on a set squish to 18 thou.
currently has 185-190 psi comp on a cold saw with assembly lube in it.

it has been flooding out. I even tried drying it out and dribbling some mix in the cylinder, no choke on. it will not even cough. pull the plug nice blue spark?

Thoughts guys?

 

[166]

Check the clutch side seal.

Is this a standard 510 or easy start?

 

[David Young]

Standard

 

[NormalT]

Have you put the original coil back on the unit and tried with it?

 

[David Young]

Have you put the original coil back on the unit and tried with it?

Yes

 

[David Young]

Check the clutch side seal.

Is this a standard 510 or easy start?

Seems ok on pressure and vac test

Took a while for set up. Next thoughts?

 

[bigbadbob]

Flywheel key???

 

[David Young]

Flywheel key???

It is cast in and perfect

 

[bigbadbob]

It is cast in and perfect

Sorry missed that in the first post,,,

 

[Fifelaker]

I remember Mastermind telling about a bad flywheel giving him fits. I don't remember all of the details

 

[Fifelaker]

Randy's thread "troublesome 660" is where I read it.

 

[166]

NGK plug?

 

[David Young]

NGK plug?

A bunch of them used and new. Should I try Bosch or champion?

 

[Red97]

Either??

Lol

Did it still flood out with the good carb?

No cuts/ breaks in the plug wire?

Have you tried the pizzed off start method??

Yank like ya trying to rip the recoil off, till your blue in the face? sometimes that does work...

Guess you could try swapping the 5105 flywheel too. seems to be getting fuel, gotta be spark related.

 

[166]

NGK BPMR7A (6703) is the plug you want.

If the 5105 is an Easy Start that is a different flywheel.

 

[Jon1212]

Necro-posting here.... @David Young did you ever find a solution for this "flooding" issue? The reason I ask is that I had a 5100S come in last week that exhibits the exact same symptoms.

Rebuilt the carb, new NGK BPMR7A, nice bright spark. I dried out the cylinder, dribbled a little mix through the intake, and it just makes my shoulder sore....personally, I think it's a faulty carb. It seems to leak down, and that funky foam ring to fix an impulse issue is lame.

 

[David Young]

No saw is apart in a box in my storage unit. I heard never use the choke and in no case more than 1 pull with choke. It acts like the pop off is too low. Maybe a stiffer spring or lower lever would help.

 

[Poleman]

Sounds like the needle isn’t seating if you have bleed-off. You may need to pressurize the carb and submerge in water to see if gaskets are leaking just to get ideas.
You could also lower the needle arm below spec to see if that helps. One thing to look for also is if you rebuilt the carb is the tab on the diaphragm may be slightly longer then original....I’m on the look out for this on any carb rebuild anymore.
These carbs are know to do exactly what your discribing when bad.
John, that little foam pad on top of the carb is there to keep the fines out of the diaphragm. It’s a pretty serious problem without one....it gets full of chips and floods the saw. Cut a v in the foam right up too but not into the vent hole....this helps with the impulse and also keeps debris out as it breaths better.

 

[Poleman]

David....just another FYI.... I worked on a 5105 last week a dealer couldn’t figure out... plenty of gas, spark...everything. Turned out to be coil. I took one off one of my saws and it fired right up. I didn’t expect that as it had a nice blue spark already. Just don’t know sometimes, but I had parts to swap out the dealer didn’t. (Husky Dealer)