Why the CRF450 and not Kawi, Suz, KTM motor for hybrids

[Logan #34's Dad]

As the title says, Why does most every person putting a dirt bike motor into a quad use the Honda CRF450 and not one of the other? When I watch supercross it seems they are all pretty close at turn one but them Suzuki's seem to get up front alot..

[89trx250r]

In my opinion its the reliability of the honda motors.

[blacknblue#2]

I dont even know if its so much reliability. The honda motors have their weak links too. I think its cost. I just went completely through my CRF motor, New crank, bearings, gaskets, new oem piston , rings, and valves and was well under a grand with me doing my own work.

[JOHNDOE83]

Honda will always be the best :bandit:

[honda250xrider]

Pretty cheap to get power out of and cheap to maintain. I only spent $1500 for all new oem parts: crank, head, vavles, seals, bearings, gasket, piston, etc. try doing that with another brand

[atvmxer79]

It's simple. Honda is the best! Obviously this is an opinion but they are cheaper, easiest to work on, very reliable, and IMO the best power with the unicam design. They have a lot of bottom end torque where as the Yamaha and Suzukis I've rode make power on the top end causing you to scream the motor.

[bsmith106]

As others have said, price of Honda parts are cheaper than other brands. Honda has been lagging in the power dept since 09. If you ride a 12 kx450 back to back with crf450 there's a big difference when stock. Kawi feels much stronger at all rpm and is stronger on the dyno too. 13 Hondas are the least powerfull bikes in the 450 class. I can't use all the power either bike makes so not to important to me, but in a heavier by 120lbs quad chassis I can see hp being more important. 09-12 crfs also come with a week four spring clutch. Not a Honda basher by any means, no brand allegiance at all but in my and many others expieriance the Kawi has a much stronger engine and is no less reliable than a Honda these days. But Honda parts are cheaper and that's a huge factor trying to compete in any long race series.

[honda250xrider]

comparing the big items between brands:

Head Crank cylinder piston

Yamaha 654.25 417.62 474.88 106.68


Honda 487.88 404.79 353.45 104.96


Suzuki - 726.04 721.39 181.74


KTM 870.96 1124.54 Both 959.16


Kawaski 669.78 438.50 377.79 112.25

This is all MSRP prices; you can find each of these parts much cheaper but this should give you an idea of the spread. Honda is cheaper as you can see; this adds up over the race season if you continually replace cranks, bearings, pistons, etc

[Groves187]

From what im told the Hondas are also easier to make good power. I have a 59hp crf hybrid stock bore stock stroke on pump gas with a hrc cam, dasa exhaust and a Demon Industries cnc head. Not really a onpoint build as far as the cam and piston and crank go and still makes really good power and rips all day long!

[Logan #34's Dad]

So it's safe to say that they make about the same power initially? I know the Honda motor is pretty light weight are the others about the same?

[89trx250r]

Bsmith just for the sake of arguing show me anyone who has used a kawi motor in a quad frame...Have you ever been on the bike forums? Cause I have read nothing but kawi problems on the 11's and 12's. Yeah Honda may not have the power stock but as others have already said they are so easy to make a **** ton of power...Look at Uppermans Honda dude gets more holeshots then anyone in the pro class.

[bsmith106]

I don't know of any Kawi engine hybrids. I was just answering the original question in my opinion. I race bikes (ktm smoker right now) and just play on quads. Of the newest 450s I've spent any time on I feel Kawi has the strongest engine most fun too. You can lug 3rd gear and still have it pull corners as easily as the CRf in 2nd. Then rev higher and stronger down the straights. As far as I know upperman is running a trx based engine. I took the ops question as asking about bike motors for hybrids. If you read mxa they just tested a yoshimura Crf ported, cam, piston, and pipe and said even though it gained 5hp it still wasn't at the level of a stock kx. I don't own either one of those bikes but have ridden both. Neither of these bikes have given the owners any trouble so far but when riding the crf the clutch started going away.just sharing my expieriance.

[mxblaster14]

Two of the top riders in Ireland run kawi quads with a kx 450 engine! No idea of power but Its probably a safe bet that they haul *** cuz they won the premier class last year.

[89trx250r]

Yea I understand what you are saying Bsmith and I wasn't even really disagreeing with you but I had never seen a kawi powered hybrid. I understand in the bike the motors hold up well but how does that relate to the extra weight and stress of a quad? I think the fact that Honda motors have been proven for years is also another thing they have going for them.

Mxblaster I have a feeling that two of the top riders in Ireland can win on anything its about 90% skill 10% bike...

[Justwin]

I ran a DS450 with KX450F engine all last season in MX with absolutely no problems, finishing 2nd in the British Championship and 2nd in the Ulster Championship (N. Ireland).

It is an awesome motor and is the clear favourite for European 450 class supermoto as it seems to produce more reliable HP than the others.

I had been looking for a CRF but the KX came up and have not regretted it.

I am doing another 2 DS/KX conversions for this season and will make a kit if anyone is interested.

[Justwin]

And the other side

[bsmith106]

Like the ds hybrid! Is that a carbed or injected kx450 engine? Any idea how much lighter it is than a standard ds450?

[Justwin]

Thanks. It's an injected KX450F, not sure on exactly how much lighter it is but it's a lot! When I get it on some corner weight scales I'll let you know.

[Logan #34's Dad]

Originally posted by Justwin
Thanks. It's an injected KX450F, not sure on exactly how much lighter it is but it's a lot! When I get it on some corner weight scales I'll let you know.
You need to get that on a dyno. Preferably one like what we'd have over here in the states...(dyno-jet). We'd love to know the torque and horsepower and what work is done to the engine.
Sweet ride!

[Justwin]

I plan to get it on the dyno now that I have the remapping software. It will be a dynojet as all my DS's were run on a dynojet and I want a direct comparison.

All that's was done last season was a 5 angle valve job by CT and a little light porting.

I was able to holeshot a few motos, so the power is pretty good and it has so much more torque than the DS is unreal. Much much more ridable.

Thanks, it was a ton of work but I'm super happy with the results

[Logan #34's Dad]

Since your a fab guy, did you notice my signature? I put a Honda CR85 in a DS and my son races it at our AMA ATV Nationals in the 90 mod and supermini classes. Was not as hard as it sounds. I'm currently building a 2nd one with a 105cc CR for that supermini class.