I have been meaning to post a thread like this since we have a lot of 450's being added to our group. We have plenty of examples of each, so I invited a few of the guys over, each with a different color 450 to compare. Here's what we collectively decided:
First off, these bikes are not the maintenance nightmares that they have been made out to be...as long as you set them up properly. As with any bike an assessment of how the bike will be used is key. For example, if you're going to log highway miles you'll want to consider higher gearing. Keeping the RPM's low is the trick to preserving the life of the engine. Not to worry, even with high gearing each one of these bikes still have plenty of power to spare.
Aside from gearing, this is what to expect if you decide to convert any of these bikes:
1) Brake switch. Whether you decide on the hydraulic switch, or choose to go all out and get an ATV master cylinder, you'll need something to activate the taillight.
2) Headlight switch. All of these bikes have a headlight, but they'll need a switch to toggle between high and low beams.
3) A tail/brake light (CRF & KLX)
4) Horn. Most states require it, however in most cases a simple bicycle horn from wal-mart will do the trick.
5) Some of these bikes would benefit from a stator being re-wound for higher output along with a regulator rectifier to handle the higher output.
Now the performance of these bikes is a moot point. I have found that they all share parts from their MX brethren and that means that you can change the performance characteristics with a simple cam and exhaust swap. All of these bikes have very similar power and I don't believe that any of them displayed any clear dominance over the other in that aspect. That being said, I'll list some things that I have noticed about the different 450's.
This bike was everything you would expect from Honda. Top of the line quality components and a solid feeling and performing bike. This bike had the most aftermarket parts installed. One that was very note worthy were the Rad Mfg. wheels with a cush drive hub. They made the bike so much more nicer to ride as well as preventing a lot of premature wear on the associated components. Another cool feature about the Honda is the separate oil reservoirs which means your engine and clutch can have different oils to better preserve their performance.
The only downside that I will mention about the Honda is the top end. This is a somewhat controversial topic, but as a former Honda motorcycle technician and through my own personal research/experience I believe that this is something worth mentioning. Hondas seem to enjoy eating valves. This doesn't mean, however, that they can't be made to be just as reliable as the rest of the bunch. Switching over to stainless steel valves along with a TRX450R (ATV) piston (for the extra oil ring) will provide you with what you need to have a healthy long lasting street machine. Though this may cost a bit more, you can't deny that the CRF is one of the best looking bikes with tons of potential.
What is not to like about this bike. With killer looks and power to match this bike is tough to beat. The transmission gearing seems to be a little close, but even with a 15T front sprocket (which will give it plenty of gear range for the highway) this bike will almost power wheelie in every gear! Love it or hate it, the green is pretty flashy and makes this bike stand out from the rest of the pack.
In my experience working on the KLX, you'll have the most trouble with chain to tire clearance. Here are a couple of links on how to deal with this issue: http://www.supermotojunkie.com/showt...ock&highlight= and http://www.supermotojunkie.com/showt...les&highlight=. Basically, with a chain block you can run either a 160 on a 5" rim or a 150 on a 4.25" rim and yes, the 160 WILL fit just fine. The only other thing to be aware of is the oil capacity. I would recommend keeping the oil filled up all the way to the upper mark.
I'm sure that it's no secret around here that this is my weapon of choice. For an overall complete package, I feel like the blue bikes are tough to beat. They are built/intended for street use from the factory (some assembly required on the US version) and can easily be converted to produce YZ power with a simple exhaust cam and YZ exhaust swap. Definitely offers a great bang for the buck and the durability of the 5 valve head makes worrying about valve adjusts a thing of the past. From my time as a Yamaha Tech, I only had to adjust 3 individual valves (on three separate bikes) in my years at Yamaha.
There are a couple of short comings though. The WR seems to have an appetite for batteries so keeping the bike on a Battery Tender is a must. Also, if you're like me, you enjoy the bike's explosive power, but this will effect your fuel range...
Love them or hate them the KTM's make for a really cool sumo. Though they are vastly different from the Japanese bikes, their uniqueness is undeniable. The biggest and best selling point on these bikes, you can pretty much decide from a 450 all the way up to a 560 and almost all of the engine/body components will interchange between the different models (i.e. a EXC 6 speed transmission from a 525 will fit right in to a 450 SX). This opens up a world of options and tons of parts to choose from. Plus the KTM accessories allow you to really deck out the bike with some serious orange flair. Since the EXC comes with a street legal title and a headlight/taillight, it is among the easiest to put on the road.
These bikes are built and engineered differently which can make them somewhat tricky to work on. The only other thing that I will mention is my KTM seems to have a thing for leaking oil. Parts seem to be a little more involved to order and take a little longer to be delivered...and tend to cost a little more.
Pick your poison. Just like anything in life, there are pros and cons to each bike/manufacturer. Just like women, you have to decide which one's short comings you are able to deal with the best. When put side by side and we all compared notes, the bikes shared more similarities than differences. With proper jetting and some well placed parts these bikes can easily be converted for $1k or less (17's included in that price). If you're in the market for a sumo any of these bikes would be among the best candidates. Lightweight and tons of power, the 450's are where it's at.