Post Number: 1
|Posted on Wednesday, October 14, 2009 - 11:38 pm: ||
I am trying to get an early 3 port engine to start. Timing is correct. Compression and clearances are good. The problem is that I can get the engine to fire only if I squirt gas/oil mixture in the plug hole. The engine will not pull through the carb and transfer to the top end. I'm running 10/1 gas oil and the old fibrous grease in the crank bearing cups. I'm running out of ideas. HELP!
Post Number: 46
|Posted on Thursday, October 15, 2009 - 06:30 am: ||
Here are some things that come to mind;....
*Is fuel sitting in an open-top tin before the carb???; that'll lose the octane quickly.
*That's a very oily petroil ratio, but I use that kind of mix in the primer bottle, and that is still plenty volatile! I have never heard of an oily-er ratio than 20:1 for the main fuel. [mine is 32:1]
*If you crank the engine with the sparking plug taken out, there should be visible fuel mist coming out - if it is going to be rich enough to be able to cold-start. If there's no visible mist; you need to open the needle valve and/ or tighten the air plunger [if schebler type] Also; 80% choke the air inlet when cranking, and/ or press the tickler down for 3 or 4 sec.
In my early days of putt putt engines I was waaayyy too scared of flooding the engine, so much so, that I starved it!!! This in-turn took more physical energy to start than to row the boat to the destination!
You should/ could always lean the mixture once it begins to warm-up.
Post Number: 14
|Posted on Thursday, October 15, 2009 - 06:39 am: ||
I can only think of two things, a partley blocked exhaust system (back pressure to high) or a crank leak.
Post Number: 1077
|Posted on Thursday, October 15, 2009 - 11:49 am: ||
What is the engine?
A couple of pics may assist one of us in spotting something
Post Number: 484
|Posted on Thursday, October 15, 2009 - 09:11 pm: ||
With the plug removed as you turn the engine over you should here a puff of compression into the cylinder on every down stroke. If not it could be crankcase leakage, a blocked intake, or the piston installed wrong. Some 3 ports have a window in the piston that has to line up with the port, if turned around it won't allow intake air in. The deflector on the piston should be opposite of the exhaust. Remove the carb and see if you feel a suction when the piston nears the top. Check the carb for blockage, I fought a rag in the intake tube of a Lunkenheimer before removing the pipe and looking in it. I sleaved an engine for a friend, he couldn't get it to run, when he made the cylinder to base gaskets he didn't cut out the transfer ports.