bad HRC cam?

[quadrcr161]

i recieved my HRC kits before my 450r and i pick up the 450r when the 1st batch was released. i installed everything but the cam about 2 weeks later. i didnt install it beacuse i figured it would be difficult since i have always worked on my 2 strokes. a few weeks ago at the track i was talking to a guy that has 2 of them for his kids to race. he was telling me how easy the cam install was except for that damn decompression bolt.

well last week (friday night actually) i broke down and installed it. it actually was pretty simple but i could not get the thing to fire and keep running, it kept dieing and wouldnt start. saturday i carried it to a friends shop where it fired right up and ran for a few mins, i had to give it gas to start it though which was strange. well as i pulled it into the shop from the trailer it made a whinning noise and we shut it down. well we tore back into it and were amazed from what we saw. the piece on the cam that the sprocket bolts to was almost ready to fall off. it had slid over about 1/8 of an inch and the whinning sound was the bolts hitting the valve cover. :eek2: i went home and grabbed the stock cam to check the timing to make sure it hasnt spun on the cam shaft.

i get back to the shop and we finish pulling it apart. the shaft looks fine and there are no swirl marks that would show that the piece spun on the cam, it looks like it was not pressed on all the way from the factory. we compaired the position of the lobes to the stock one and everything lined up perfect. we took it over to the press and pressed it back on, if it felt loose i wasnt going to use it but it took some pressure to press it back on and it was tight. so we put it back togeather and fired it up, and started adjusting the carb. we finish putting the plactic and everything back on. he takes it around the side of the shop and goes around a few trees to see how it feels, he has a decked out yfz, but he didnt get on the gas. i carry it home and let it warm up and go for a quick ride, this thing has no power, then it shuts off and dosent want to start. it seems like the jetting could be off but it ran great before the cam install. anyone have a sugestion? i wish i took some pics but my digi cam was left at work that weekend.

[lukester720]

1st what is your jetting? Do you have the hrc lid on or the stock lid on? Did you measure the valve clearence? Mine wasn't all the way right from the factory. Did all 3 marks line up? It sounds like it could be out of time. Reply back and I will try to help you.

[quadrcr161]

i have the hrc lid on, and i have the hcr jets in it. what do you mean yours wasnt right fromt he factory? its in time we double checked that. we also checked the valve clearance. the guy that helped me when i knew something wasnt right is from Terry Racing, he has been in enough motors that i trust him and so does cutris sparks. he has a top end from a crf in his trailer and several others.

[lukester720]

[QUOTE]Originally posted by quadrcr161
[B]i have the hrc lid on, and i have the hcr jets in it. what do you mean yours wasnt right fromt he factory?


The clearance on one of my intake valves was a little off from the factory. I would try removing the jets to make sure there is nothing clogging them, if that is not the problem there could be something wrong with the cdi/ignition.

[quadrcr161]

it ran perfect with the stock cam, and all that was changed was the cam. i do think the jetting could be off because i have to give it gas to get it to kick over. as soon as i get well, im sick and drugged now, we are going to try to rejet it and see what happens. if it dosent work tyhe stock cam goes back in and the hrc cam is shipped back to honda.

[benwa450r]

Make sure you adjusted the decompressor. Six-thousandths I believe. If misadjusted, you could be loosing compression and burn exhaust valve. Main should be 185 and jet needle on 3rd or middle clip. Good luck.