Hello all - in need of your expertise.
I ve acquired my grandfather s M135 (Continental gas) that has been sitting for a number of years. The issue I m having is that it dies after running for a few minutes after its warmed up.
It cranks up great every time with no choke even when cold. It runs strong while running even under a load. However, after a few minutes it will rev down and die like its running out of fuel. Give it a minute off and it cranks right back up with no problem but then dies again about a minute and a half later. When it starts to rev down, if you play with the choke you can get a few more seconds out of it, but it will still die. It feels like a fuel starvation issue like its using the fuel out of the bowl and then dying, but I m no expert. It runs for about the same amount of time each time you try. It will die while under way or just sitting stationary idling.
In getting it running again here are the things I ve done:
-service/fluid change
-new plugs and plug wires
-new points/condenser/distributor cap and rotor
-new tank and fuel lines and fuel
-carb clean (and new carb explained below)
I originally put a knock-off replacement carb on it when I first started working on it. It cranked and ran well on the knock-off carb but it would not go up hill. Any time it was on any incline it would rev down and die like it s doing now. It would go up the incline backwards with no issue but any time it was nose up it would die. I was thinking it was a float sticking issue. After removing the new carb several times/confirming float height and movement I gave up on it and went back to the old carb and cleaned it. It ran great for a few days on the old carb and then started this cycle of dying (but it will go up hill while its running).
It still seems like a fuel starvation issue. When it dies, the sediment bowl is full of fuel. Also thought maybe a vacuum issue and removed the fuel cap while running - same result and it still died. As mentioned above, tank is new, valve and sediment bowl cleaned. New fuel lines. I need to confirm there is fuel in the carb bowl when it happens but ran out of light today.
I m obviously missing something and may be chasing the wrong cause entirely. Reading the forums on similar issues but not making any headway. Any guidance you can provide would be appreciated - working 90 seconds at a time is challenging.
Thank you,
I ve acquired my grandfather s M135 (Continental gas) that has been sitting for a number of years. The issue I m having is that it dies after running for a few minutes after its warmed up.
It cranks up great every time with no choke even when cold. It runs strong while running even under a load. However, after a few minutes it will rev down and die like its running out of fuel. Give it a minute off and it cranks right back up with no problem but then dies again about a minute and a half later. When it starts to rev down, if you play with the choke you can get a few more seconds out of it, but it will still die. It feels like a fuel starvation issue like its using the fuel out of the bowl and then dying, but I m no expert. It runs for about the same amount of time each time you try. It will die while under way or just sitting stationary idling.
In getting it running again here are the things I ve done:
-service/fluid change
-new plugs and plug wires
-new points/condenser/distributor cap and rotor
-new tank and fuel lines and fuel
-carb clean (and new carb explained below)
I originally put a knock-off replacement carb on it when I first started working on it. It cranked and ran well on the knock-off carb but it would not go up hill. Any time it was on any incline it would rev down and die like it s doing now. It would go up the incline backwards with no issue but any time it was nose up it would die. I was thinking it was a float sticking issue. After removing the new carb several times/confirming float height and movement I gave up on it and went back to the old carb and cleaned it. It ran great for a few days on the old carb and then started this cycle of dying (but it will go up hill while its running).
It still seems like a fuel starvation issue. When it dies, the sediment bowl is full of fuel. Also thought maybe a vacuum issue and removed the fuel cap while running - same result and it still died. As mentioned above, tank is new, valve and sediment bowl cleaned. New fuel lines. I need to confirm there is fuel in the carb bowl when it happens but ran out of light today.
I m obviously missing something and may be chasing the wrong cause entirely. Reading the forums on similar issues but not making any headway. Any guidance you can provide would be appreciated - working 90 seconds at a time is challenging.
Thank you,