I NEED HELP!!!
I have an odyssey and it was running well then I stopped it for exactly 2 minutes to put air in a tire and went to start it back up and the electric and pull start work fine but it doesn't turn over. I tried brand new spark plugs, starting liquid, cleaned the carburetor, but nothing helps. the only thing that has happened was once or twice I would get "snorts". this means it would make one big, hissing firing, but that's it. suggestions?

By no means do I mean to be a smartass but does it have gas? Any cracked fuel lines or in the vacuum line comin from the crankcase?
Do you have spark?

yes it has spark and gas tank and lines were my first replacement. I have a new plug working well, and gas lines and filters

also, I don't have a fuel pump and haven't for a while. the left crankcase vacuum line serves no purpose because I have the gas gravity fed

any other suggestions?

Sounds blown up to me. An odyssey cannot be ran off of gravity fed tanks for long because they starve for fuel and lean out and melt the piston. Do a compression test I bet its below 100 psi. The odyssey engines require twice as much fuel as a standard 2 stroke. that's why they used a fuel pump. Test compression and put the stock tank and fuel pump and lines back in.

where can i get a pump and/or tank for cheap?

Its an odyssey nothing is cheap for them lol. There is a guy in the forsale section selling a tank and pump for 35 bucks I believe his handle is joshdirtbike. Whats your compression at?

idk but its pretty good. I also tried starting fluid into the spark plug hole and straight into the reed valve but still nothing happens. and even without the fuel pump and tank, why would it have run for so long on gravity fed?

just got done looking at it with my friend who is an inventor and mechanic and he said everything is good except for the spark. it looks good when outside, but inside it might not be a good enough spark and be too weak. either that or its sparking at the wrong time. im looking into a new CDI (Capacitor Discharge Ignition) unit. suggestions on places to look? on ebay the lowest price was $72. not sure if there will be a lower price but its worth asking

Whats your compression ?

Shoubadaba, denuch has a 350 that runs like really well on gravity feed, it has for almost a year. I question whether it would blow because of this? I do agree with the starving for fuel then yes it will blow. Interesting...

what exactly does "blowing" entail? does this mean the entire Engine is ruined or what?

Most likely topend. Melted and sunk in dome or melted rings into piston losong compression. Topend rebuild is bore hone and new piston,rings top bearing and wrist pin.

Hes is running gravity fed without a pump?

Is it all stock? How big is his main jet? What carb?
I would like to see how his buggy runs. Is it sluggish on topend and mostly ridden in trails at a slow pace?
I have been building and playing with odysseys for over 20 years and have never seen and odyssey gravity feed only last more then a few weekends out. Long WOT (Wide Open Throttle) runs causes a lean condition and poofkaboom.

Check spark by leaving your plug in the Engine and put a new one on your coil and crank the Engine over under normal load and check for weak spark. What is the compression number. You could be chasing and waisting money on a CDI (Capacitor Discharge Ignition) unit. We on here have never heard of an fl350 CDI (Capacitor Discharge Ignition) unit go bad. We have heard of sheared off woodruff keys though on the crank.

my friend the mechanic I getting a CDI (Capacitor Discharge Ignition) for free and we'll see how that goes, but what else could be the problem? ive tested everything and it all checks out. I just don't see what else could[i][/i] be going wrong other than something electrical. a.k.a. the CDI (Capacitor Discharge Ignition) unit. any other suggestions that I might not have checked already?

and as for the gravity fed debate; I have found that the only thing that's bad about having it set up like this is that you cant put even the thinnest filter over the air intake or else it barely goes. so I just leave the air intake wide open and it works fine. ill probably end up putting a very open mesh over it just to stop major debris from flying in.

Soooo your running without an air filter?

It's all stock as far as I know. He only went to gravity because he didn't have enough vacuum to run a pump on the oem setup. Jetting is probably stock too. It has had some dying out issues a few times after running WOT (Wide Open Throttle) but never a poof kaboom. It's kinda a mystery from what it sounds like... LOL

Kiwi, hopefully your friend will get the correct CDI (Capacitor Discharge Ignition) or it won't run right. Put a air filter on it or you'll be sorry when it goes boom. DO A COMPRESSION TEST and post results. You may also need to do a leak down test too...

If he doesnt have enough vacume to pulse the pump then his rings are shot. If it dies after WOT (Wide Open Throttle) its because of no pump. Wont be long til it will need a topend. Have him look for a pump. He can still run the gravity tank just add a pump to it with the stock T and return

Where is the return line going to goto? The tank is above the Engine. He needs to do a top end then put the oem tank back in or use gravity with the pump... I thought if he couldnt draw enough vac maybe the case seals were bad?

how do I do a compression and leakdown test?

It goes back to the tank like the stock set up