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My '04 won't start/kick start seems 'light' any ideas why please?

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1 Minute Ago

rotecdhrider

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Join Date: Aug 2009

Posts: 110

My CRF is hard to start and compression doesnt seem to build. Any ideas?

Hi guys,

I have an 04 CRF I had the water pump seals and the valves checked two rides (approx 3hrs running ago).

I Rode it two weeks ago and it started and ran a treat. I did fall off though and snap the hot start cable. It ran fine anyway so i finished the day. I went away for two weeks, went to start it today and it didn't want to start.

I bumped it no probs and it ran perfect all afternoon (approx 1.5hrs). I did manage to start it once hot with pliers pulling the hot start cable. But other than that bumped only.

It ran perfect: no oil loss/smoke, no coolant loss and no power loss.

The thing that is baffling me is that the kick start doesn't seem to crank up compression like it used to (I would kick it around 3 times then it got stiff-ready to start). Instead now it seems to be light/easy to kick all the time. It does not seem to build up.

Any ideas what it could be? Maybe exhaust valve clearances/not shutting properly?

Any ideas would bE great thanks.

Cheers!

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That's what I was thinking. Is it the exhaust valves that wear/stretch most frequently? The bike had a few mods when I bought it, one of which being steel valves so hopefully they can be adjusted/shimmed to cram some more hours out of em!

I guess if it was running fine then there's little chance of damage.

I will check 'em out ASAP.

I should also say that approx 6hrs ago (of easy running, not on the limiter once) my mech did the base and head gasket saying everything looked mint inside (no marks on the Teflon on the piston etc)

Thanks for the input

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Ah ok. So that would cause it to be hard to start and e 'light' feel to the kick starter?

It did run great once going though.

Hopefully it hasn't done any damage!

Thanks

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Ah ok. So that would cause it to be hard to start and e 'light' feel to the kick starter?

It did run great once going though.

Hopefully it hasn't done any damage!

Thanks

The valves going bad will cause the issues you're having. Chances are, you will need to replace the valves and have the seats cut.

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Hmm. Cash I don't have!

What sort of cost is involved to replace the inlet valves?

Cheers

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Hmm. Cash I don't have!

What sort of cost is involved to replace the inlet valves?

Cheers

For stainless steel intake valves, you can find pro-x on e-bay for about $100 US currency. They come with the springs and are not too bad. The seats will also need cut and they are usually around $30 per seat US currency.

If you run hi-level MX, you might want to consider using the stock titanium valves. They rev a bit faster, but most don't even feel the difference. The stock valves are right around $50 each and you really shoud replace the springs and they are about $8-$10 each. This is doing it yourself. Having them done can run as much as $300. You'd need to find a shop in your location and find out how much they charge for the job.

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Thanks for the guide prices. I suspect it's pretty much the same values here in the UK. I don't ride hi-level mx at all. I do not race, only practice on motocross tracks approx once a month. I do not rev hi, infact I honestly think I have hit the limiter three times in the year I've owned it!

Thanks again,

Jay

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If you do end up having someone do your head for you, or atleast cut the seats, dont go directly to the local motorsports shop. Best chance is that there is a machine shop or engine builder who can do it alot cheaper and can have a discounted access to all topend parts.

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Thanks for the guide prices. I suspect it's pretty much the same values here in the UK. I don't ride hi-level mx at all. I do not race, only practice on motocross tracks approx once a month. I do not rev hi, infact I honestly think I have hit the limiter three times in the year I've owned it!

Thanks again,

Jay

The way you ride, I would say in your best interest would be to get the stainless steel valves. Since you don't live on the rev limiter, it would be a great choice for you.

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For me it's about longevity so the steel it is then!

Thanks for all your help.

Jay

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For me it's about longevity so the steel it is then!

Thanks for all your help.

Jay

Not a problem!

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My mechanic has looked over my bike now. He inspected the clearances and it was indeed the inlet valves that were at 0. He has re-shimmed them and the bike starts first or 2nd kick.

He did say that next time they go out it is best to replace them, but for now there is life in them.

Thanks for all your help guys

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Look around online for someone to send it too, here in north america a lot of people seem to reccommend Agent Smith racing. So much so that I'm sending mine from Canada to the US for them to do it. Ask around on some UK sites I guess. Chances are you will be able to shim them before you have to send it away so you'll have some time to research. Make sure whoever does your work is going to replace seals, springs and re-cut the seats etc.. Don't just put new valves in.

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Agent Smith knows his stuff and is very reputable. You'll want to start looking for someone to do it right away. After re-shimming, you won't get much time out of it. Usually a couple of hrs if your lucky. You just put a bandaid on it for now. Don't even attempt to re-shim it again. The valves are shot.

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