When I bought my 350 the jetting was way off. Ran pig rich.

I leaned it out and got it running great. Then, over time it would only run well with the air intake hose disconnected from the airbox, now its to the point where it wont run right unless the whole airbox lid is removed (they really bark without the lid too!). At some point in this process I may have switch from regular to premium fuel and what brand 2 stroke oil I was using.

One other thing, maybe related, maybe not. If I let the machine sit for several months, I need to crank and crank it to get fuel to the Engine. I have a clear line from the pump to the carburetor and it is empty when it sits and slowly fills up as I crank then it finally fires. Not a problem if it sits say overnight, but longer time.

That sounds like your compression is way down.
Other thing could be your pump is shot. Do a flow test.

Having to crank the Engine for a long time if it has sat for months is common. I was going to put some type of priming bulb on mine so I wouldn't wear out the starter.

To get mine started after it has sat, I pull the gas cap off and put a little pressure to the tank and it pushes fuel to the carb and she starts right up.

If performance is falling off and you have to remove the air box where you didn't before, check your compression.

Rand

Where does the fuel go? Evaporate?

She still runs like a raped ape with the lid off. Wouldn't say the performance is down. I could check compression though.

The raped ape comment scares me. That's an indication of a lean out and you are saying you have to crank it a lot to get fuel to the carb after sitting. You better do a flow test. In my machine with a new pump and an empty tank it only takes about 5 seconds before she fires after I refuel even if the lines were empty. Every man for himself.

What is a source of a new pump or a rebuild kit?

But if its rich when running and has fuel in the line when I shut it off one would think its getting sufdicient fuel when running?

I would have thought someone would mention needle and seat or float level or something with the symptoms.

Yes, the fuel just evaporates. Again, it's common to have to crank it for 15 seconds or so if it sits for a couple of months. Both of my Ody's with rebuilt fuel pumps and 140psi compression have to be cranked excessively if they have been sitting for a month or so.

Here's a link to the stock fuel pump rebuild kit.

http://www.ebay.com/itm/Keihin-Fuel-Pum ... 1807854830

Rand

That may not be the problem, that's why you need to do a flow test -- 4 1/2 oz in 10 seconds approx.
The pump we use is from a Polaris because it is easy for me to get. Polaris #3085275.
If your needle n seat gone then it would be super rich and would flood.
Float level is a possibility.
Like I said check one thing at a time and narrow it down.
Check the dangerous stuff first. Like air leaks then intake then fuel flow from pump then float level etc.

No that's not true. I know this for a fact by the way. I had a fuel pump deliver just enough fuel at idle and half throttle and then when I went to full throttle booooooom hole in piston.

The symptoms you are having with having to pull the air box off are the same symptoms that Duneit was having with one of his pilots. When we pulled the lid of the air box off, it ran great. With it on it ran like crap. We then checked the compression, it was extremely low and time for a rebuild.

Check your compression!

Rand

Throttle open or closed? Numbers OK if its 25 degrees F out? Will put a charger on battery while cranking.

WOT (Wide Open Throttle), with a full battery. Crank it until the needle stops rising.

What altitude are you at? Altitude will affect your readings.

Rand

Also the other option is a Mukuni fuel pump BUT make sure is it a genuine Pump and not a knock off or copy.

http://www.ebay.com/itm/Mikuni-14-Liter ... JD&vxp=mtr

And as for a primer

http://www.ebay.com/itm/Fuel-Primer-Plu ... 1802019376

Yeoddy

I would like to add.

Make sure its not a intermittent spark problem, when the spark plug does not fire you lose combustion temperature which supports combustion you also carry some of that unburned gases over to the next cycle creating a over rich mixture to be burned and it makes the Engine seem like its lacking power and running rich.

Check your reed petals this can cause a two stroke to run rich.

Check your spark arrestor if you still have the factory exhaust.

Compression is at 135psi, same as 3 year ago when I checked it.

Randiestman, I thought this rebuild kit wasn't a good match for own fuel pump on the 350?

The Winderosa rebuild kit works very well for the FL350 pump.

The problem is there are no assembly directions for the kit and they are quite the puzzle to figure out. Once they are assembled properly, they work very well. I rebuilt my Ody and Mrs Randiestman's Ody with the kit and both are performing flawlessly.

Randiestman

Sounds like an opportunity for a how to post.

So what should I try next, rebuild fuel pump, different jet in carb?

Do a fuel pump flow test like Can Ody suggested. Only until you know you have proper flow should you begin messing with the jetting.

Remember, something has happened to the Ody to change the way it's running..... jets don't wear out.

Rand

Flow test...get Engine warmed up, shut off and then disconnect fuel line to carb and start up and run for 10 seconds then shut off, or 10 seconds of cranking, or do on a cold Engine cranking over?

Just remove the fuel line at the carb and crank it over with the starter. NO IGNITION.
Caution fire !!! be safe.