'05 WR450 New Cam new Springs???

So my buddy wants to put some hot cams in his wr450. Will he need to replace the valve springs also?

Unless they're incredibly worn no, but he may want to give some serious consideration to replacing the headlight fluid :lol:...SC

well check this. We put a high compression piston in it and a set of hot cams.

He rode it for a day and he ended up blowing it up. Well actually his piston hit a valves after 5+ hours of riding it. The valve broke and bounced around for a bit and then got wedged in the spark plug. He wanted to blame me for the probelm but i said no way. So he calle je and told them what happened and they said it was the soft stock valves springs that could not keep up with the aggressive lobes on the cam causing the valves to float a bit and allowing the piston to hit the vlaves at hight revs.

Dude at Je pistons also said that the piston is reuseable. He said to grind the chunk of metal out of the piston and it will be fine. SERIOUSLY!! &%$#@!???

well check this. We put a high compression piston in it and a set of hot cams.

He rode it for a day and he ended up blowing it up. Well actually his piston hit a valves after 5+ hours of riding it. The valve broke and bounced around for a bit and then got wedged in the spark plug. He wanted to blame me for the probelm but i said no way. So he calle je and told them what happened and they said it was the soft stock valves springs that could not keep up with the aggressive lobes on the cam causing the valves to float a bit and allowing the piston to hit the vlaves at hight revs.

Dude at Je pistons also said that the piston is reuseable. He said to grind the chunk of metal out of the piston and it will be fine. SERIOUSLY!! &%$#@!???

Hadn't heard of having to replace springs but your explanation sounds plausible because hotcams do have more lift than OEM. Thats one reason I have a YZ ex cam because it has the same lift as WR.....hotcams don't appeal to me for the lil gain in hp.

Unless they're incredibly worn no, but he may want to give some serious consideration to replacing the headlight fluid :lol:...SC

Some of the quad engine builders will tell you to change the springs, guides, keepers, and valves too with the Honda's just for a cam swop. Thats probably where the changing spring idea came from. I think its all a rip-off. Main reason I got a blue bike.

all the hot cams are designed to work as "drop in" pieces, with no additional mods necessary.( ok there are a couple that aren't) you dont NEED springs to use that cam, unless yours are in need of replacing anyway

I have a High Comp piston and Hot Cams in my bike along with a Vortex ignition that raises the rev limit by 1000 RPM. I raced in Motard for one whole season and never had a problem. I had the bike wide open for long straights at some tracks. I did do some port/polish on the head towards the end of the season and tested the springs. They were getting a little soft. I just replaced them with stockers and it runs like a raped ape!!!

come to think abou tit, it was the exhaust side that hit

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