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Discussion Starter · #1 ·
i bought a 2007 honda 300ex the kid put a Chinese cdi and over reved it and floated a valve and destroyed the top end. heres what i did brand new head with stage 1 cam wisco high comp piston new jug and a bigger jet to compensate for the build..

PROBLEM!! the motor went together fine, it started Right up but its making a knocking noise but its not the bottom end the rod and bearings were fine. i think its the valves tapping the piston not to sure tho, when i did the timing i couldn't seem to get all the marks lined up right, but very close. the one line is pointed straight up and the other 2 are almost straight across the line on exhaust side is slightly down?:confused::confused::confused:

CAN SOMEONE HELP ME???
 

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Discussion Starter · #3 ·
When you put a ring in the cylinder and squared it up with the piston, what was the end gap?
i forgot what it was but i did make sure it was within proper gap. but the valve rockers are really flat and messed up, and i spoke to a guy over at Honda by me and he said that most likely is my problem and that's where the noise is coming from, so i ordered new rockers and tappers they should be here this Wed-Thurs, ill keep you up to date on if it works or not!!!
 

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Never put in a new cam with old rockers unless the rockers look like new. Inspect your new cam closely - replace it if there is any sign of galling on the lobes.

Note: the most common reason for rockers to be worn is a lack of lubrication - make sure you have oil pressure to the head. With the engine running, loosen the oil pipe banjo bolt at the head and make sure oil is being pumped to the head. If there is oil pressure, shut the engine off and inspect the bolt connecting the pipe to the head to ensure it is hollow. If it was inadvertently replaced with a standard bolt, the head will run dry and destroy the cam, rockers and the head.
 

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Discussion Starter · #5 ·
Never put in a new cam with old rockers unless the rockers look like new. Inspect your new cam closely - replace it if there is any sign of galling on the lobes.

Note: the most common reason for rockers to be worn is a lack of lubrication - make sure you have oil pressure to the head. With the engine running, loosen the oil pipe banjo bolt at the head and make sure oil is being pumped to the head. If there is oil pressure, shut the engine off and inspect the bolt connecting the pipe to the head to ensure it is hollow. If it was inadvertently replaced with a standard bolt, the head will run dry and destroy the cam, rockers and the head.
well i bought the quad from some kid who didn't take care of it so im assuming he ran it low on oil, but when i took the valve cover off after the noise happened it was very wet with oil but i will double check with the banjo bolt just to make sure and also its a brand new cam i got i just didn't replace the rockers or tappers but there coming this wed so it should be good and P.S. i only had the quad for a week now lol.
 

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Discussion Starter · #6 ·
okay i just put in the new rockers and tappets the bike is a whole lot quieter but im still getting a slight chatter and ideas?? and valve clearance is .004 intake and exhaust
 

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Most clicking and ticking comes from the cam chain and piston. Overhead cam engines can run upwards of 12 thousandths valve clearance and not make any noise. My race motor calls for .008 intake and .013 exhaust (not that the motor is quiet), but a loose motor runs faster than a tight motor.

Put your motor on TDC and loosen the cam chain tensioner to see how far it will come out from it pushing on the cam chain. If it quits pushing on the chain when it's a quarter of an inch or less out, then the cam chain needs replaced. If it is still pushing on the chain at 3/4 of an inch, the chain is probably good.

Gas was never mentioned. The engine was designed for 92 to 93 octane. Since you put in a high compression piston it is imperative to run high octane. I use 94 motor octane race fuel which is 100 octane using the (r+m)/2 method. there are lots of articles on octane on the internet - here's a good one Octane rating - Wikipedia, the free encyclopedia

Finally, it's an air cooled motor. Some noise is normal.
 

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Discussion Starter · #8 ·
Most clicking and ticking comes from the cam chain and piston. Overhead cam engines can run upwards of 12 thousandths valve clearance and not make any noise. My race motor calls for .008 intake and .013 exhaust (not that the motor is quiet), but a loose motor runs faster than a tight motor.

Put your motor on TDC and loosen the cam chain tensioner to see how far it will come out from it pushing on the cam chain. If it quits pushing on the chain when it's a quarter of an inch or less out, then the cam chain needs replaced. If it is still pushing on the chain at 3/4 of an inch, the chain is probably good.

Gas was never mentioned. The engine was designed for 92 to 93 octane. Since you put in a high compression piston it is imperative to run high octane. I use 94 motor octane race fuel which is 100 octane using the (r+m)/2 method. there are lots of articles on octane on the internet - here's a good one Octane rating - Wikipedia, the free encyclopedia

Finally, it's an air cooled motor. Some noise is normal.

Thanks a bunch ill check over everything and will see what happens thanks
 

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Discussion Starter · #9 ·
okay silly me... i forgot to rotate the motor after adjusting the valves so they were of spec. i just re adjusted them and its much quiter but im still getting an abnormal tic
 
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