300 is making me go NUTS!

[Pvt. Maggot]

alright..i got my motor all back together...got spark..got fuel going in...checked the timing..it seems right..we changed it a whole bunch of times...still no luck..it just turns over and turns over....sometimes it shoots flames out of the pipe..sometimes it doesn't...but it just won't fire..give me ideas..i'm goin nuts...it has spark..its getting gas in..it has compression...i'm so confused...does anyone have the 300 manuel that says the exact way to put it in time.....please help :(

[300exOH]

It sounds to me like you may have it 180 degrees out of time. Not positive though.

[Dunlap]

You may have spark but it's week. Did you do something to the wiring when you had it apart or something inside the clutch cover with the reverce switches? The spark you see is the ignitor.

[Pvt. Maggot]

i wired a cr250 kill switch for my starter and my pro design wired in...me and my dad both said it seemed like a weak spark...we checked all the grounds and connectors though...i dunno whats wrong :o i dunno if its out of time because i don't know the real specs...:(

[Dunlap]

Put the wires back stock. To time it just put it back the way you took it apart.

[SpeedBump]

Sounds like the other dude said, 180deg out of time. I believe the way to get it in time, is this.....
Get the piston to TDC(top dead center)on the compression stroke. Place the cam in with the LOBES DOWN. You will know you are on the correct stroke when the piston is at TDC and the cam lobes are down and BOTH rocker arms have a bit of freeplay. finger tighten the rocker box and leave off the small caps to check the rocker arms) Line up the "T " on the flywheel through the site window (small hole in side cover) with the indicator on the sidecase. Make sure that the timing chain sprocket is on correctly too. There should be 2 timing marks on the sprocket. These marks should be at about 9 o'clock and 3 o'clock but they will be EVEN with the cylinder head, NOT HORIZONTAL with the ground. The engine is tilted a bit forward, so you must line up with the engine, not the ground. Be sure that the timing chain adjuster is released when you check all these things. You will probably need to move the chain a tooth or 2 either way a few times to get it exactly right. Turn over the engine a few times to check eveything out before you try to start it up. Take notice of the timing marks and the "T " as to where they are when the piston is moving through its cycles. Hope this helps.. Also, I would take the kill switch off and only use the wiring that you need to run the machine, UNTIL you get it running. You may have something not right with the kill switch and not know it. After you get it up and running, THEN install the Kill Switch. Good luck

[beak7707]

SpeedBump is exactly right on how to time the motor. Make sure the T on the flywheel is lined up with the line on the cover. Then line the 2 marks on the cam spocket up with the top of the head. The first time I ever worked on a 300, I timed it 180 out of time and I bent the exhaust valves. If you did have it out of time you better check and see if you bent your valves.