Author Topic: FL250 No Start  (Read 4316 times)

abrahamsengine

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FL250 No Start
« on: May 22, 2012, 08:18:08 AM »
I am trying to help a neighbor out with his fl250.  He bought it in pieces.  After putting it back together, it did not run.  He brought it to me.  I fixed some ignition problems and it ran great.  He took it back and after just a few days, it died while driving and would not restart.  At first I thought we had a fuel pump issue, but I cannot even get it to fire if I dump a bit of fuel into the cylinder.  I think I have good fire.  I am not sure how this thing works internally.  It doesn't seem like I have any suction when I put my hand over the intake side of the carb.  When I do this, I feel pressure and my hand gets covered in fuel.  It also does not seem to be getting the fuel from the crankcase into the cylinder.  When i crank it for a while, the plug still comes out dry.  It feels like I have good compression when I crank.  The pull starter feels about the same as it did when it was running well.  Any suggestions would be great.  I am an auto mechanic, and I would really rather avoid anything 2 cycle.

Brent

LiveWire

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Re: FL250 No Start
« Reply #1 on: May 29, 2012, 05:58:53 AM »
Compression needs to be checked with a gauge. The FL250 has a really small starter pulley and pulls over hard even if the compression is down.

abrahamsengine

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Re: FL250 No Start
« Reply #2 on: May 31, 2012, 09:42:12 AM »
I don't find a compression spec in my Clymer, but with a gauge, I was able to get 70 psi after two pulls and 80 after four. 

Thanks
Brent

whammo77

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Re: FL250 No Start
« Reply #3 on: May 31, 2012, 04:44:52 PM »
Compression should be right around 130 psi.

What year Oddy is it? That is kinda important when trouble shooting... knowing whether it is a points or CDI system. If you don't know the year, look at the engine itself... see where the wires lead (and how many there are) coming out of the engine. If it is a CDI, there should be 4 wires, and one of the wires will lead up to the CDI before going to the coil. Actually, knowing the year isn't fool proof... I bought one that was an '83 with a '77 engine in it.....

How long had it been sitting in a non-running state prior to you working on it?

There are no valves, so don't worry about that being your problem.

Have you actually pulled the plug out and then pulled the rope to see if it is actually getting good spark?

If it feels like the engine is not sucking through the carb (and perhaps even getting back pressure), try removing the exhaust pipe and pulling the rope and see if it gets suction then (and/or tries to start). The exhaust pipes on these things can get plugged and cause it not to be able to run. I have had this happen. This would help explain the lack of suction and/or back pressure. Would also explain the fuel problem....

Check those things out and post what you find...



 



abrahamsengine

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Re: FL250 No Start
« Reply #4 on: June 22, 2012, 02:25:09 PM »
Thanks for the help, and sorry I have not gotten back sooner.  Things got a bit busy with summer vacations.  That compression number is higher than I expected given the slow cranking speed.  I am sure that the cylinder and rings have some wear.  The ignition is a CDI, and I have good spark with the plug out.  If I have time I will put a secondary ignition scope on it to see if I have good spark under compression in the cylinder.  It seems like the exhaust problem could be likely.  I will try pulling off the muffler.  If there is any interest here, I made some captures with a scope of how the ignition works.  When I first saw this thing, it had good fire, but at the wrong time (I used the scope to verify this).  I found that the little trigger winding under the flywheel was installed backwards.  Turn it around and it started right up and ran great.  The owner had it for a few days before it died and he brought it back.