Lectron for 2008 450X, thoughts?, experiences, rec's for new carburetor, por favor

My BIL has this 2008 450X. This FCR carburetor has been a mega PITA.

I think of replacing it with something, anything and either the Lectron ($799 with NO carb heater yet) and the Smartcarb-if one is even made for the 450x, are tempting with no jets and simple external adjustment(s).

Can anyone recommend a simpler/easier to dial in carburetor for the 450X for the cold/snow-what we do that is just awesome?

I am now an expert at pulling out and putting back in, the Keihin FCR carburetor from a 2008 CRF 450X.

I also finally got the bike running correctly and here is the full story for your reading entertainment.



The bike came with the airbox modified. The top had been cut open and there was some cut out of the exhaust-side of the airbox.

The bike came with a Yoshimura muffler.

During last winter, the fuel screw had fallen out and this had caused massive backfiring. As the bike was a 2008 and it had not been used in a while, between the in-tank fuel screen degrading and sending all the plastic particles into the carburetor, and a dirty funnel that was used to fuel up the bike, the carb was clogged with stuff.

I had gotten a carburetor rebuild kit from All Balls and having not known a thing about jetting, I had stuck the 145 main jet in. It came with a 158.


I put the fuel screw in but had no idea that it needed a spring, the washer and then the o-ring.

When I had pulled the fuel screw out today, the o-ring was halfway down the screw and not doing a thing to seal anything up in the carburetor.

I had also turned in the idle screw as it was so far down in the carb, it took a LOT of turns just to get it to hit the throttle cam.

I even sent the carburetor to FCR.com and had the guy clean the carb and replace all the wear items for just under $200-this was still money well spent as I had no idea and still don't want to deal with all the seals and diaphragms in the most complex of carburetors.


All these things were NOT helping this bike to get started and run correctly. If anything, I got a running education on jetting and the FCR carburetor.



I checked the pilot jet and it is a 45. Someone else runs the 45 in the winter so I made sure it was clean and put it back in its place. The pilot that came with the bike was also a 45.

I swapped the 145 main jet that came with the All Balls kit for the 165 that was recommended by JD jetting. The bike came with a 158. The 145 must have been way too small and I think I'm lucky we did not burn the motor down from being so lean.


I put the blue needle in the 4th/middle clip position.


I put the carburetor back together. Fuel tank back on. Pulled the choke out and the bike fired right up on the second try and idled perfectly. No backfiring, no hunting. When I turned the idle screw up and down the idle went up and back down like it should.

I had the RD flex fuel screw adjusted 1 1/8 out as was recommended and as I had installed it correctly, have not yet gone to adjust it as it was in the 40's tonight so I want to wait until it is cold out before I mess with it.

I bought a stock muffler for the 450X and it will get here tomorrow. Getting the peace and quiet will be so, so nice as we both hate the noise the Yoshimura puts out.

At least it is not the intake valves. It will be so nice to have a touch and go bike again and not need to pull the choke out every time the bike needs to be re-started hot.

At least the saga with this bike should be over and I finally got it (mostly) dialed in. I will surely fine tune it once I get it back on the snow.

Thanks for all the help guys, I appreciate it.

GKR said:

You going to run carb heater? I would recommend it as I have an FCR on a KTM and had a few issues before I did the carb heater. Now it has no problems. I used the KTM electric heater and have some pics of the install if you are interested?

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Hello,

I had spoken with Brad, from PST last winter and he had learned that the CRF450 does not need a heater, that the engine jacket is more than enough to keep the carb from freezing and after a full season, in every condition, we never had any issue with the carb freezing at all.

The engine jacket does a bang up job plus, we get a LOT less snow than you guys out west. I don't think I ever saw handlebar pow once but for some stashes where it blows and stays.

I think that because we are on the East Coast/Vermont and from 600' to maybe 1,500', and have a LOT less snow than you guys out west, we had no issues with carb icing on the 2008 CRF 450X.

We do have a PST engine jacket and have even left off the cold weather panel as the engine runs warm enough without it.

Norma Stitz said:

I believe carb icing can be made worse by steam and snow injection, but true carb icing is caused by certain atmospheric conditions combined with reduced pressure and fuel evaporation in the Venturi. It’s actually in a zone of temps and if colder icing will not happen. Just above freezing and partial throttle is the recipe as long as the humidity is there. Imagine a fog forming in the carb that deposits on the slide. Colder air can’t hold the moisture required, warmer air won’t hit the dew point under that level of vacuum.
Anyway, I have no idea how this relates to a lectron, as they operate a little differently than I’m used to.

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You hit the nail right on the head as last Saturday night, it was just above freezing and as humid as could be.

Jaynelson said:

Another POV....if you are considering spending $800 on a carb (which sounds like $1000 once you add a heater)....would that money be better spent selling the carb bike and upgrading to a newer fuelly?

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Bike was $3,000.

Camso kit was $4,800.


A newer FI 450 would be about the cost of both the bike and the kit.

I finally sorted out the FCR carburetor on the 2008 CRF 450X. It is starting and idling perfectly and for the short ride around the yard I had taken, the engine is finally running mint.