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540 kit vs. 570 kit (EXC)

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I'm curious to learn what anybody has to say about these two kits. I've heard of them both but don't really know too much about 'em, and who makes them? Any reviews?

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I tried to start a thread like this a week ago or so and didn't have much luck. I'm also curious. I have heard the 570 kit is good, but why. Anybody....info? Thanks!

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cblabate,

I did respond but it's hard to answer your questions unless you ask for specifics.

Here's a list of avalible options for the RFS motor

540 kit 97mm piston (actually 530cc) factory kit ($800) or aftermarket piston (11.5/12.5:1 pistons) and overbore cylinder ($500)

550 kit (543cc) 98mm piston and sleeved/plated cylinder $700 (available in 11:1 or 13:1 compression)

570 kit (554cc) 99mm piston (11:1 compression) and sleeved and plated cylinder ($700)

580 kit - (576cc)97mm piston and 78mm stroker factory crank ($700) and either 540 kit

590 kit (588cc) 98mm J&E piston and stroker crank 11:1 or 13:1 pistons

600 kit (600cc) 99mm kit and stroker crank (11:1)

Any kit with 13:1 compression needs race gas. 12.5:1 and the 8/06 or hot cam can run on premium as long as the valves are unshrouded.

FYI J&E says you can run the 98mm piston with just an overboar but I feel the cylinder walls are to thin and won't install a 98mm piston in a overboared cylinder.

The 72mm cranks build revs quicker and the long stroke cranks rev slower but make more torque.

CAMS

You can tune power even more depending on cams used

55 grind great bottom but flat above 1/2 throttle.

8/06 cam bottom equals stock nomatter which kit it's used with. Good choice for 11:1 kits great all around power.

HotCam best when used with higher compression kits and/ or the stroker kits. Gives good bottom end power with geat over rev. I wouldn't use the Hot cam with a 72mm crank and standard compression. To much bottom end loss with this set up.

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Thats a lot of good info. What I'm trying to do is make my bike more MX'ish if thats possible. A little bit more snappier when on the throttle. I'm really not sure what kind of kit or compression ratio I would need, so any reccomendations if any would be appreciated.

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Snappy & more "MXish" is light crankshaft and short stroke. That would be start with a 03 525SX crank and use one of Travis's big bore stock stroke combos. Then consider having him trim more weight yet, use with the SX ignition

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The 97mm 12.5:1 piston and 8/06 combo gives a all over power increase. It will give you more snap as well as more peak power I would unshroud the valves to lower compression slightly and reduce the need for racegas.

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The 97mm 12.5:1 piston and 8/06 combo gives a all over power increase. It will give you more snap as well as more peak power I would unshroud the valves to lower compression slightly and reduce the need for racegas.

Which Bore size would this produce..540cc? Is this worth the time and money? Sorry this is all kinda new to me so I don't mean to ask dumb questions, gotta learn some time.

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Which Bore size would this produce..540cc? Is this worth the time and money? Sorry this is all kinda new to me so I don't mean to ask dumb questions, gotta learn some time.

This was already answered in Travis_D-37's first response.

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I would be looking for something on the relatively less expensive and more reliable side. Would I be best with the "570" kit? And will my stock cam work ok with this setup or would you strongly recommend the 8/06 cam for this?

Who puts together these kits??

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That's original what I asked before I edited my post; I assumed he did..Do you provide the sleeving and plating services too Travis? And do you have a website? PM if necessary..

Ya, I think the 540 kit is probably my best bet..

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That's original what I asked before I edited my post; I assumed he did..Do you provide the sleeving and plating services too Travis? And do you have a website? PM if necessary..

Ya, I think the 540 kit is probably my best bet..

I've been working on the web site for 6 months but don't seem to ever find the time to finish it.

I've been doing the 453 to 600 kits for a few years now. About 1/2 the time I have cylinders alread made into kits and work with an exchange program that way your not down for 3-4 weeks while sleeving and replating your cylinder. OR if I don't have one avalible I usually have one in processing so you can still ride until the kit gets to you.

We offer replating as well as resleeving. you can reach me at 661-713-4295

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I'm running the KTM stroker crank, 8/06 cam and JE custom piston (had to have 4 made) with a 560 jug sleeved and bored to 4.060 giving me a total of 650cc's. I have the Akrapovic titanium fully open exhaust and a Keihin 41mm carb.

The stock 525 cylinder head has been thoroughly worked over with bigger valves, springs, better guides and porting work. Its about 14:1 on compression using custom cometic (copper) head gasket and base gasket.

Its a real hand full and will straighten your arms out in 4th and 5th gear. With its current gearing (14-42) it will top out at 120mph and cruise at 80.

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I'm running the KTM stroker crank, 8/06 cam and JE custom piston (had to have 4 made) with a 560 jug sleeved and bored to 4.060 giving me a total of 650cc's. I have the Akrapovic titanium fully open exhaust and a Keihin 41mm carb.

The stock 525 cylinder head has been thoroughly worked over with bigger valves, springs, better guides and porting work. Its about 14:1 on compression using custom cometic (copper) head gasket and base gasket.

Its a real hand full and will straighten your arms out in 4th and 5th gear. With its current gearing (14-42) it will top out at 120mph and cruise at 80.

Travis help me. He's hanging that shiny thing in front of me.... Travis built me a 570 very good power all over... Tom

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Count me another satisfied Travis customer.

I have his 570 kit with the Hotcams cam. Works great though it runs noticeably better on the 95 gas we have here in Thailand than the 91. So unshroud those valves if you go that way and want to run on Premium 91 in the states. I love the upper end pull of the Hotcams over the stock cams.

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cblabate,I did respond but it's hard to answer your questions unless you ask for specifics.Here's a list of avalible options for the RFS motor540 kit 97mm piston (actually 530cc) factory kit ($800) or aftermarket piston (11.5/12.5:1 pistons) and overbore cylinder ($500)

550 kit (543cc) 98mm piston and sleeved/plated cylinder $700 (available in 11:1 or 13:1 compression)570 kit (554cc) 99mm piston (11:1 compression) and sleeved and plated cylinder ($700)580 kit - (576cc)97mm piston and 78mm stroker factory crank ($700) and either 540 kit590 kit (588cc) 98mm J&E piston and stroker crank 11:1 or 13:1 pistons600 kit (600cc) 99mm kit and stroker crank (11:1)Any kit with 13:1 compression needs race gas. 12.5:1 and the 8/06 or hot cam can run on premium as long as the valves are unshrouded.FYI J&E says you can run the 98mm piston with just an overboar but I feel the cylinder walls are to thin and won't install a 98mm piston in a overboared cylinder.The 72mm cranks build revs quicker and the long stroke cranks rev slower but make more torque.CAMSYou can tune power even more depending on cams used55 grind great bottom but flat above 1/2 throttle.8/06 cam bottom equals stock nomatter which kit it's used with. Good choice for 11:1 kits great all around power.HotCam best when used with higher compression kits and/ or the stroker kits. Gives good bottom end power with geat over rev. I wouldn't use the Hot cam with a 72mm crank and standard compression. To much bottom end loss with this set up.

I know this is an old post but question for TRAVIS,

I have been eyeballing your 453 kit for my 2001 400EXC for a while. Do you have a steel sleeve kit? or is there only a Nikasil sleeve available?

I know that running cooler is one of the benefits of the Nikasil coating, but I thought steel sleeves might offer better long term/cheaper service ?

Opinions / options ?

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I am not Travis but I disagree on running steel to save money. The Nikasil is going to out last the piston anyway. For most riders that combo is good for 2 to 3 years minimum depending on air filter preperation

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I am not Travis but I disagree on running steel to save money. The Nikasil is going to out last the piston anyway. For most riders that combo is good for 2 to 3 years minimum depending on air filter preperation

Thank you Sir !! That's what I was looking for, more info. Good enough for me. :thumbsup:

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