Dolmar PS-510 starts and dies

[Rivets]

If it is in the fuel system, I’m guessing a bad pickup tube on the fuel tank!!! Craftsman, this is a 2-cycle engine.

 

[ILENGINE]

Hmm... Is it a Valvetrain problem or a plugged exhaust screen? Never heard of this engine brand before.

Chainsaw 2 stroke

 

[ILENGINE]

Alright guys the cause of failure is a faulty ignition module. Welcome to the world of digital spark advance with integrated rev limiter ignition. So try to diagnose a faulty ignition without loosing spark. Symptom mimics a chainsaw or trimmer that is running out of fuel in the tank.

First time I came across this was with a Dolmar PB 251.4. Blower would run about 30-45 minutes and then would start bogging and would die unless you released the trigger. Would idle all day long. Since this blower is 4 stroke, I changed the fuel lines, replaced the spark plug, adjusted the valves and replaced the carb. Still would not fix the issue. Contacted Dolmar and talked to tech support. And after talking to the head guy he determined that it was a faulty ignition module. Replaced the module and ran like a new one. Since then I have probably replaced 20 modules over the last 10 years.

 

[Rivets]

Ok, that’s a new one on me, but even at my age I’m not too old to learn. I’ve heard of this on a 4- stroke engine, but never on a 2-stroke. Thanks you for teaching this old dog a new trick

 

[Craftsman Garage]

Ahh, almost said the coil but you tested spark. I hate all these DSAI systems. Such a gimmick.

 

[Scrubcadet10]

@Rivets @slomo @Scrubcadet10 Any of you guys have any thoughts before I reveal the answer.

I haven't read the thread, I'll read through and see what I think

 

[Scrubcadet10]

Oh wow, very interesting fix. I would not have considered that, unless I got into a "throw parts at it" mindset.

 

[ILENGINE]

Oh wow, very interesting fix. I would not have considered that, unless I got into a "throw parts at it" mindset.

They best I can determine is the spark advance chip goes south and throws the timing off to the point it won't run.

 

[Tiger Small Engine]

Alright guys the cause of failure is a faulty ignition module. Welcome to the world of digital spark advance with integrated rev limiter ignition. So try to diagnose a faulty ignition without loosing spark. Symptom mimics a chainsaw or trimmer that is running out of fuel in the tank.

First time I came across this was with a Dolmar PB 251.4. Blower would run about 30-45 minutes and then would start bogging and would die unless you released the trigger. Would idle all day long. Since this blower is 4 stroke, I changed the fuel lines, replaced the spark plug, adjusted the valves and replaced the carb. Still would not fix the issue. Contacted Dolmar and talked to tech support. And after talking to the head guy he determined that it was a faulty ignition module. Replaced the module and ran like a new one. Since then I have probably replaced 20 modules over the last 10 years.

Sometimes the tank breather on a backpack blower will get dirty and start causing the engine to bog down. Ignition coils rarely go bad in two stroke equipment. This post makes me remember a Husqvarna I worked on last year with similar issue. I still have the chainsaw and will try a different coil. Thanks for the post.

 

[StarTech]

As I said anything is possible. The first and last time I saw coil failure like this was a Homelite chainsaw about 13 yrs ago. So this is a very rare problem apparently.