I see a lot of FCRs and the like from Honda/Suzuki/Yamaha/Kawasaki 250 motocrossers. Is there any particular reason one of these would not be compatible with the KLX? I've lost touch with the MX stuff so I have no idea what the electrical plug is for on some of them. I just wonder why these wouldn't be compatible. I've seen from $86 to $150 for one of them.

Any thoughts or input on this?

 

For the most part a carb is a carb, proper jetting and proper size would be your issues as well as cables, even a 2 stroke carb can be used in 4 stroke applications.

 

Most of the late model units have a throttle position sensor that allows the ignition timing to use multiple maps based on tps and rpm. Like linkin5 said, if you can fit it up it will work with some tuning.

 

I believe the FCR requires intake and air cleaner boot adapters to work with the KLX

http://www.dirtbikeworld.net/forum/s...ad.php?t=48122


http://blogs.yahoo.co.jp/kz1300a2/archive/2011/11/5 (Google Translate)


On this set up at least the accelerator pump looks very close to the exhaust pipe

 

Mark, I saw in one of your comments about the FCR that you said it came on the KLX300...maybe over on ADV. I noticed in one of Richard's links that a guy said he got an FCR off of a U.S. KLX300. He may have, but that carb never came on a KLX250/300 series. The 300 had the same, dull CV carb that we have/had. Mark, I know you have a great deal of tenacity when it comes to things mechanical, but I think you will save yourself a lot of headache and time in the long run by using a TM36. I'd never suggest that one of those FCR's off a full-on MX racer will not work on a KLX...but...some pursuits might not be worth the effort in the long run. I didn't have to buy any extra parts...throttle cable, adapters, etc...to install the 36.

 

^^^+1 The TM36-68 Mikuni bolts right up and made a big change in the responsiveness of the bike. When I need to get it to loft the front wheel over an obstacle I just twist the grip and up she comes. It was pretty much a bolt in swap.

 

The 35 I found was "intended" for a 300. It was a pumper, but no choke circuit. It was the one I sent you the listing I think. Only $50, but no choke. I don't have much faith in cranking the throttle a bunch of times on a 20 degree day and hoping the bike will start.

I am becoming resigned to the fact that the only sensible move is the TM36 so I'll sit back for a while "with a line in the water" hoping to catch one on a good buy until I decide it is time. If by then I don't "catch" one I'll pony up the bucks. Still, I kind of wondered what was on the CRF150R (the actual racer that took the place of the CR80R).

I do want to take a serious look at re-timing the cams. It makes sense, based on an article that Joe Minton did a few decades ago on the Honda Nighthawk S. He mentioned the general timing range that makes the best power and that the S was quite a bit out of that range. The retimed cams didn't put out quite the horsepower at peak, but pulled a lot stronger through the entire power band. I'm going to find a reliable shop to do the compression release removal and re-installation should I do it.

For now it is pipe and carb "jetting" to suit. Going to the Dial-A-Jet again. Worked killer on the big KLX so why not here. The carb is lean to start - exactly what Thunder Products calls for. The pipe is an incredible piece, much like the one on the big KLX. A formed megaphone cut and welded up to fit, much like an expansion chamber. If it can do what the other did, it should be fun.

As for now I'm going to have to focus funds on our propane gas bill, which seems to have gone from $1.499/gal to $3.599/gal - an $889.71 fill up! Can't wait for spring/summer when a tank goes quite a long way.

 

I hate those BA$TARD$..........just sayin' I feel your pain

 

Ditto-just had my tank filled today-$3.81/gal WTF!!!

 

Where I'm from in Canada, we're currently paying (been fairly stable around this price point for a while) $1.30/liter - which is like $4.91/gallon. I wouldn't mind paying $3.81/gal...