Timing is controlled with the CDI box. Has it been sitting for a while? What's the compression? Has the carb been cleaned? Does it have good-new fuel or old fuel? Are the plugs wet/fouled?
Are you 100% positive it's getting fuel cylinders? Tried a small-short shot of starting fluid to make sure it's getting fuel into the cylinders?
Do a compression check-new fuel-new plugs-clean carb and check your fuel pump.
If it's sat for a while w/out being run or has bad fuel--it probably won't start. It may look as though there is fuel to the carb--but getting into the cylinders is another story. A quick shot of ether (if the compression is good) will tell you if it is getting gas or not--as it should start- if it's not getting fuel or enough fuel it won't run long. At least you'll know it's starving for fuel--you'll have to figure out why (i.e. fuel pump,carb etc.) and fix it.
Yes-there are timing marks on the motor. I beleive those are for a set timing configuration at the time the motor is put together--it has to be at a certain timing mark. The timing advance (curve) is then controlled by the CDI box.
If the plugs are wet then it is most likely flooded. I would remove the fuel lines and pug them or remove the fuel line from the tank to the pump and remove the plugs--pull it over several times (to expend all the fuel from the cylinders)-reinstall new plugs and leave the choke OFF and try to start it. If it starts let it go several seconds-shut it off-reinstall the fuel lines and start it again--keep it going and start making your neccessary adjustments.
Also make sure you have really good spark- if you use an in-line spark tester it should be very bright. I have a CDI box on one of my Cats that shows spark--not very bright--but it's there. IT WILL NOT START MY MOTOR!!! I had to put a different CDI box on that had brilliant/bright spark before I finally got it running. I was chasing after fuel issues and spark plugs and cleaned the carb a couple of times before I finally figured it out. Just to make sure--after I got it running, I reinstalled the CDI box w/ weak spark--it wouldn't start--put the other one back on and BAM!!! Running again! Normally CDI boxes work or they don't. I just happen to be the one guy in a million that has a CDI box with weak spark that won't fire a motor!
Did you rebuild the motor yourself?
Did the motor run before you rebuilt it? If it didn't then I would say it may be a weak CDI box. If you have another sled that runs or a friend that has a sled check spark on it. You will see the difference between weak spark and good spark. Are you using a in-line spark tester or are you just grounding the plugs to the motor? An in-line spark tester is easier to see, plus you can leave it on when the engine is running to see if it gets intermittent spark (cuts out)if you suspect a dead cylinder. You can find them at any parts store or some hardware stores for less than $10
Anyway--if you see a difference in the brightness between a sled that runs and yours-- I would suspect the CDI box is too weak to start it.
I am assuming you removed the crank and/or the flywheel. It may be possible that you did not get the timing marks where they needed to be when you put it back together. I have never had a flywheel off and do not know if it is possible--but I imagine it is--since there are timing marks there. Somebody should have a book (if you don't)that explains the timing setting during rebuild situation. I would imagine one or both of the pistons have to be at a certain location when the timing marks are lined up.
thanks racohoon for taking time to aswer some of my questions. the engine was not running before I bought it. and didn't run after the rebuild.I'm going to try to time the engine by moving the stator plate.I just don't know which cyl. to use to set timing PTO side or Mag side to be at BTDC. and what degree.
Old Cat Rider or somebody can get those specs/info for you. They will probably chime in here some time soon and may let you know what you have to do--there are a good group of people in this section.
Sorry I can't help with that.
If you have an eltigre 5000 with the ad50f2 engine timing should be .080 BTDC it will be obvious wich cyl to use as the wrong one will be at the bottom of its stroke.
If you have the 4000 with the AB44f2 engine my manual does not cover that, sorry
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