>>And allowing time between attempts with the spark plug removed to address possible flooding.
Some Tecumseh engines can require up to a half hour to clear a flood even with a pulled and dried plug. I’m not sure why that is but it might be gas saturated in the carbon buildup. ?
Tecumseh’s can be extremely fussy with primes and choke and flooding easily as mentioned above. Finding the right combination is a pain and take many attempts over time to get it right for some engines.
The way sort things out is to pull the plug often to check for dampness or dry.
1 ½ on the main and 1 on the idle should be fine for starting and tweaks not needed. ¾ to full throttle should not make a difference. Choke and prime will swamp the small throttle difference and the governor will probably have the throttle butterfly open anyway.
Give it 1 prime and 4 pulls at full choke and pull the plug. If not damp, two primes, full choke and 4 pulls. If the plug is not damp 3 primes, full choke and 4 pulls then pull the plug. If not damp look to carb cleaning. If the engine puts check for black smoke.
If the plug is damp through any of those tries wait a half hour with the plug out and do the same level of prime and choke on one pull and back off the choke one click for 3 pulls and check the plug. Adjust on the condition of the plug.
Another is: spray ether or gas into the throat, full choke and 4 pulls. If wet and no start look into weak spark or being grounded.
Give the engine is fairly new compression, valves and probably spark are ok. You get the “rumbling” and to me it seems like flooding (not backfiring which would be lean). If you get that again check for black smoke on the puts as it seems from what you’ve described your flooding.
I’m working on one at the moment which behaves like yours and it’s flooding for some reason very easily. It’s takes a single soft prime on this engine every few pulls and backing off the choke after the first pull to get it started. Just a little over prime or pulling a time or two and not backing off on the choke will flood it. A very fussy starter.
Anyway it’s good not to pull too much and check the plug often to see where things stand. Whenever wet give at lest a half hour rest with the plug out.
ADD: If you give it two stiff primes does gas dribble out of the throat?
This message was modified Dec 28, 2012 by trouts2