fl250 fuel pump

[fl250driver]

my odyssey is currently not running and im really getting sick of it especialy cus my brother just bought a fl250 in great condition (the guy had just restored it completely) for 500 bucks and it starts right up.
my odyssey will get a spark so thats not the problem
and it turns over so the piston is not seized
the only problem left is not getting fuel.
it has the stock fuel tank and i think it might be the fuel pump.
i dont understand fuel pumps on odysseys
how do they pump the fuel since there is no battery?
any ideas?
could it be the fuel filter?
any help is greatly apreciated
o and when the odyssey was running before it had a very loud piston slap.
could this be the cause of it not running?
if i get it running i will take a video of it running so you can hear the slapping.
o and the fl250 is a 1979

[K-fab]

Okay, let's start from the beginning:
It will run, but makes a lot of noise.
It's hard to start.

First thing to do is check the compression. If the piston's making all sorts of noise, that means it's worn out. That leads to low compression, which leads to a hard to start, poor running engine.

Unfortunately I can't tell you what a good compression number for a 250 is, but I would imagine that it needs to be at least 130 psi (which is probably quite low). 150 is probably more in line for a newly rebuilt top end.

Don't run it with a loose piston much more. If it's worn out, the piston will rock in the bore and the rocking will eventually knock the skirts off the piston. When that happens they like to go play in the bottom end bearings. It can destroy an engine past repair.

Fuel pumps on the Oddy's use a pulse line from the engine. You should have four lines that go to the pump - one from the pump to the carb, two that go between the tank and the pump (one is feed, the other is return) and then one that runs to a nipple or fitting somewhere on the engine.

The pump has a series of diaphragms in it that move with each engine pulse and draw/pump fuel through them. The line from the engine to the pump supplies these pulses with each rotation of the crank.

If your oddy's fairly old (duh, they're all old...) Let me rephrase that...
If your oddy has any corrosion in the tank, there's a good chance that the fuel system's plugged and/or has stuff in it.
This can lead to crap in the bowl/needle & seat of the carb
crap in the fuel pump diaphragms
crap in the fuel filter.

Also, make sure that the fuel cap can still vent. It should (or the tank should) have a one way valve that will let air into the tank, but not let it escape. If this is stuck, the tank can form a vacuum and not let the pump get fuel to the carb.

One way to check your pump is to pull the line off the carb, then turn the engine over a few times w/the pull starter and see if there is fuel coming out of the line to the carb.

You may want to check out Pilot-Odyssey.com or The Pilot Odyssey Pit Stop (POPS) for more technical help. There are some really sharp 250 guys on those boards.

Hit up PilotHawk (owner of the POPS site) on this board too. A pm will probably get his attention.

[fl250driver]

got it running

[Bugpac]

Originally Posted by fl250driver

got it running

What was the culprit?

[fl250driver]

it wasnt getting fuel as predicted
i took off the hose that come from the fuel pump and goes to the carb and tryed the throttle-no gas came out. i tryed pulling the engine and no gas came out.
then i tryed the old blow in the gas tanks and what do u no gas came out
i then had my grandpa hold the throttle wide open and hold the gas while i pulled the beast. (after re hooking up the hose)
she wouldnt start.
i was then pulling it by myself and she started.
i took a video of it running so you guys could hear it cus there is definently some piston slap compared to my brothers fl250.
ill try to post that soon
thanks guys

[fl250driver]

started her up again today
1st pull!!!