David Bradley Update

[pafire]

Hello All,
I recieved my carb rebuild kit (tillotson HL )today, after installing the kit the saw started and ran fine until it warmed up and started to backfire from the exhaust and shut down. After adjusting the idle mixture and the main fuel jets the saw will idle and accerate to wide open. When the saw runs at peak rpm for a few seconds it will backfire and shut down. The saw will restart with a couple of pulls on the starter rope. When trying to cut with this saw it doesn't seem to have the power it should. Is my problem in the carb or in the timming. Also can anyone provide the timming spec. for a David Bradley Model # 917.60004 (sorry for the long post)

 

[sedanman]

How's the fuel line/filter that's feeding that freshly overhauled carb? Is the fuel tank venting? Air needs to be able to get into the tank to replace the fuel that's being sucked out.

 

[treeclimber165]

Never messed with timing much, I'm only 37 so I grew up with electronic ignition. But it sounds like the timing could be retarded too far.

 

[gatkeper1]

The 917.60004 has the Power Products AH-47 motor. Some of those(AH-47) had an ignition cut out governor. These short the ignition once max speed is reached. If you have the externally mounted I.C.O.G. the max speed is 4400-5000rpm, with the internal mounted I.C.O.G max speed is 4500-4700rpm
Just a possiblity that the governor might be out of adjustment.
Ignition points should be set at 0.020"
the points should open when the piston is 0.175" BTDC.
If the timing marks are aligned on the crankcase and magneto stator the timing can be assumed to be correct if the points are properly adjusted. There is also a note that on some models the timing is non adjustable

 

[Methoss084]

Sounds like its time for some points and a condensor. A saw should not backfire unless there is water in the fuel or an ignition problem. And unless its an 025 I doubt it has a sheared flywheel key.