PB-200 will only start on choke then die.

[shostoppa]

It's about 3-4 yrs old. I cleaned the carb. changed all filters and plug. Its was running fine then died. After cleaning it, it was a bi#ch to get started and now it only starts on chock, then half chocke and dies. I did not make any adjustments. Any help would be appreciated.

thanks.

[Right Touch]

did you clean the carbon buildup out of the exhaust?

[shostoppa]

When I first got it I pulled the muffler screen off It would not have to deal with it... I just fixed it though..I decided to change the fuel line and I noticed a small slit at the grimote, I replace the line and it runs great.
thanks.

[shostoppa]

OK..so I thought I had fixed the problem...now it will run for a bit then sound like it's boggin, possible no fuel, i'll try yo take the carb apart tomorrow.

[echoman8]

OK..so I thought I had fixed the problem...now it will run for a bit then sound like it's boggin, possible no fuel, i'll try yo take the carb apart tomorrow.

I have posted before about this most dread of all symptoms = "It runs good until it warms up and then it gets no fuel."

Actually that is true. The fuel delivery system on a 2 cycle is dependent first on the lower end of the engine to develop crankcase pressure and vacuum. If there is minor damage there then there is no vacuum to draw the fuel from the carb.

When a motor is cold it is tighter. As it warms, it expands and then a worn motor (on the lower end) cannot produce crankcase vacuum and no fuel will get to the engine.

Remove the muffler and seach for any dull spots (rather than chrome) near the ports and especially look at the intake port (near the carb) for scores which would indicate alcohol damage. Use a very bright light to inspect.

echoman

[shostoppa]

What do you mean by "alcohol damage"? and would this have something to do with the 10% ethenol in gas? I run Shell 89 and I have an echo weedeater that is 3x the age of the blower.
thanks.

[ed2hess]

I have a PB650 blower that is about 10 years old. The unit will start- but not easy -and will run in idle mode. It will run at the high end if I feather the choke constantly. I know the seals on crank are fine and so are the bearings. I know that that rings and groove are clean and top of piston was was ground clean and a new head gasket was put on. The compression measures about 100 - 110. All the stuff like plug, fuel filter, breather and fuel lines all new and outlet ports clean as a whistle.

My thoughts are that the rings are just worn too much to pull in fuel? If it is the rings I wonder if new rings would raise the compression enough to fix the situation. I fix these things to learn as much as possible to work on the newer stuff.

[matt9923]

I have a PB650 blower that is about 10 years old. The unit will start- but not easy -and will run in idle mode. It will run at the high end if I feather the choke constantly. I know the seals on crank are fine and so are the bearings. I know that that rings and groove are clean and top of piston was was ground clean and a new head gasket was put on. The compression measures about 100 - 110. All the stuff like plug, fuel filter, breather and fuel lines all new and outlet ports clean as a whistle.

My thoughts are that the rings are just worn too much to pull in fuel? If it is the rings I wonder if new rings would raise the compression enough to fix the situation. I fix these things to learn as much as possible to work on the newer stuff.

Rebuild the carb.
Did you vaccume/presshure test the crank case?
id say you wnat 120-150psi but im not farmiliar with this blower. New rings are what $20 and a lite honing is worth a shot.
Matt

[echoman8]

What do you mean by "alcohol damage"? and would this have something to do with the 10% ethenol in gas? I run Shell 89 and I have an echo weedeater that is 3x the age of the blower.
thanks.

Hi,

When you use gasahol in a two cycle engine the ethanol and gasoline can and will seperate in the presence of water such as condensation or any other method that water enters the fuel tank or the fuel storage container. When the alcohol seperates it joins with the water into a fuel/water mix. This mix is heavier than the gas/oil. It settles at the bottom of the gas tank and has no lubricant. This alco/water will burn and run.

When this water/alcohol in drawn into the motor, it strips the existing oil on the intake port and scores the intake port or transfer port. The culprit in alcohol damage is the presence of water.

I pour water in with my gas mix, shake it, let it sit overnight and pour the good fuel/oil mix off the top to another container.

Esentially I have re-refined the fuel.

During the 80s there was a gasahol push and I saw hundreds of ruined chainsaws from this.

Hope this not the problem with your motor,
echoman

[echoman8]

I have a PB650 blower that is about 10 years old. The unit will start- but not easy -and will run in idle mode. It will run at the high end if I feather the choke constantly. I know the seals on crank are fine and so are the bearings. I know that that rings and groove are clean and top of piston was was ground clean and a new head gasket was put on. The compression measures about 100 - 110. All the stuff like plug, fuel filter, breather and fuel lines all new and outlet ports clean as a whistle.

My thoughts are that the rings are just worn too much to pull in fuel? If it is the rings I wonder if new rings would raise the compression enough to fix the situation. I fix these things to learn as much as possible to work on the newer stuff.


Hi,

I would suggest that you remove the cylinder and take it to the very best shop and ask that the most experienced tech inspect it for lower end damage.

The compression test is useless with this problem. The compression test will test the integrity of the top end of the engine, but gives no indication of the bottom end.

If it is not feasible to remove the cylinder, then take off the muffler and take the blower to a good shop to have it inspected.

If you are certain that there are no air leaks to the crankcase/carb/intake and no fuel restrictions, then lower end cylinder damage/wear is a probability.

If the motor runs more poorly as it warms (may even die and not restart till cool), then damage is almost a certainty.

I am assuming the ignition is firing properly.

Good luck
echoman