[Foreman52]

Whats going on Guys and Gals, I have been on here before with a few questions about my Foreman 400. I tore in to the motor replaced the timing chain, bored the cylinder out .25 new piston, rings, valve seals, ect. The problem i am having with the quad is that it will run and start great however when idling it will knock about every 15 - 30 seconds and sometimes die right when it knocks at low idle. It will start right back up again. I have placed the T and checked the cam to make sure the dot lines up with the arrow inside the case. I adjusted the valves, they sound good not ticking. the knock every 15 -30 secs will stop when you are above an idle. Any Ideas?

 

[shadetree]

Whats going on Guys and Gals, I have been on here before with a few questions about my Foreman 400. I tore in to the motor replaced the timing chain, bored the cylinder out .25 new piston, rings, valve seals, ect. The problem i am having with the quad is that it will run and start great however when idling it will knock about every 15 - 30 seconds and sometimes die right when it knocks at low idle. It will start right back up again. I have placed the T and checked the cam to make sure the dot lines up with the arrow inside the case. I adjusted the valves, they sound good not ticking. the knock every 15 -30 secs will stop when you are above an idle. Any Ideas?

piston could be hitting the head..valves could be out of time.

 

[Foreman52]

I went back out to mess with it some more and noticed with a piece of paper that when I rev the motor the paper is blown away from the intake tube. On my Fly well it has two lines about a half a cm apart in addition to the two marks there is a line with an F on it then a line with T on it. I am assuming that the T stands for TDC when adjusting the valves. I am thinking the blowing back through the carb is a bent Valve or bad adjustment?

 

[shadetree]

I went back out to mess with it some more and noticed with a piece of paper that when I rev the motor the paper is blown away from the intake tube. On my Fly well it has two lines about a half a cm apart in addition to the two marks there is a line with an F on it then a line with T on it. I am assuming that the T stands for TDC when adjusting the valves. I am thinking the blowing back through the carb is a bent Valve or bad adjustment?

could well be..the T is for top dead center..this is where you set the flywheel when you adjust or set your valves..do not use any other mark on the flywheel when adjusting the valves..the F is for when you are checking the timming..which is odd..because the timming is only adjusted by the c.d.i ! strange i know..lol..if you got the valves off..you may have bent a valve..i would pull the head and check it...just to make sure..before you run it anymore.

 

[Boris]

Only a thought, my 87 Kawasaki Mojave made such a noise also at idle. I found out that my crank bearings were getting worn. I pulled the engine and took it to a shop, they put in the new bearings. I asked the guy what he thought, first thing he asked is what kind of oil and how often I was changing it. I changed it often enough, but was using automotive engine oil. Seems the shearing of the oil moluclues left the oil not working like it has to in a cycle engine.