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some carb related hand-holding please

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Hi guys, could use some advice please.. Got this new looking '07, with street legal title.. The bugger has some issues, one is the e-start doesn't work which I believe is the compression release is out of whack and two, which is why I'm writing, the off idle throttle response is terrible.

Maybe some people would like that but the bike is mostly gonna be used as a supermoto so smooth throttle pick up is pretty critical. This thing.. it basically does nothing as you crack the throttle and next thing is, it wheelies. No in-between.

It looks like the previous owner was not that mechanically gifted (from all the stripped/busted up shit I find when they went for installing jet kit) but he got into the carb and installed R&D accelerator pump cover. I took the carb off, jetting is 165/70/45. Needle from JD jet kit I believe with red paint on it, second groove from the top is what was in there. It was doing this crap when it was 65-70 ambient and doing it now at 40. I removed the smog stuff completely, blocked it off at the head and carb. The bike is now running with Akrapovic slip-on and airbox has been opened up, although I'm throwing out the X subframe and airbox and putting R subframe/tank/seat/plastic on. X version pisses me off for some reason, I'm used to R's now.

Anyway, the carb didn't look dirty inside, everything seems fine. Bike starts very well hot or cold and has very good power once it's opened up.

Where do I look for problems? The carb slide was in correctly and the slide plate was on right as well. R&D acc. pump seems to be Ok and the adjustment didn't really do much to curing the abrupt throttle response.

I have a known good carb laying around from an '05 CRF450R, if I just use the X jets will it be an option for a quick fix?

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Just struck me, I think I should also check if they installed an aftermarket cam, given that PO wanted aftermarket accelerator pump they might just have been tuning for that hit. Off to get the head cover off...

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Hm now there's another thread saying decomp system changed in 07 so if the PO installed a cam from the "wrong" year would it be harder to kick and not turn via e-start? Calling Sherlock Holmes!

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..or I guess I could just put an entire R head on it and use R carb as well with jetting as-is?

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Hm now there's another thread saying decomp system changed in 07 so if the PO installed a cam from the "wrong" year would it be harder to kick and not turn via e-start? Calling Sherlock Holmes!

That was for the 450R only, the X was still the same as '05--'07.

I would start by pulling the entire carb off and cleaning and inspecting everything. Then go from there, did you say that there was a 70 Leak jet in there? If so change it out to a 55 or 50. And yes you need to see if there is an aftermarket cam in there. As far as the needle goes, I would put it on the fourth clip from the top. If there is a stock cam, then the 165 is fine but if there is an aftermarket cam in then start at 170 and move up from there until you find the sweet spot. Check the fuel screw too, start at 1 1/2 turns out and fine tune it from there.

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check the pilot jet, could be a small speck of dirt causing a lean condition just off idle. Very common

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Cam is stock, or at least cam lobe measures same as stock from the shop manual. I'm now fairly convinced it's the plate on the slide that was upside down. The gap on decomp lever was way out, like .8, hopefully that'll fix the inability to e-start. Trying to sort out the jetting situation now, I vividly remember there was a table somewhere, but I can't find it in either competition manual or shop manual. Must be in the little handbook that came with the bike?

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Wow the poor starter motor on this thing is cooked good. The reason it wasn't working well was looks like at some point it got real hot and one of the two brush springs got hot enough to not be a spring anymore. So the brush didn't have much contact. The wiring looks pretty sorry too, I think I'll just get a new starter.

The takeaway is, don't try to use the starter if the battery is almost dead.

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Wow the poor starter motor on this thing is cooked good. The reason it wasn't working well was looks like at some point it got real hot and one of the two brush springs got hot enough to not be a spring anymore. So the brush didn't have much contact. The wiring looks pretty sorry too, I think I'll just get a new starter.

The takeaway is, don't try to use the starter if the battery is almost dead.

Don't depend on the kickstarter, as it's stop plate inside the case is known to fail and break the case. Rebuild the starter, put in a litium ion battery.

Your power band issues are probably accelerator pump and exhaust related.

Put in a Merge racing pump linkage spring, adjust you pump linkage, put in a 50 leak, pack your muffler nice a tight, and adjust your valves.

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Don't depend on the kickstarter, as it's stop plate inside the case is known to fail and break the case. Rebuild the starter, put in a litium ion battery.

Is it a different design than a 450R? If so any way to address the issue? I'm 140lbs so I'm not breaking off the kick-starter any time soon. Bike usually starts on first kick anyway.

Your power band issues are probably accelerator pump and exhaust related.

Put in a Merge racing pump linkage spring, adjust you pump linkage, put in a 50 leak, pack your muffler nice a tight, and adjust your valves.

Well if the plate was upside down all of the rest of this is just minor details :lol: There's a Quickshot 3 already installed and an o-ring mod done by PO so I should be able to tune it pretty well shouldn't I? Other than jetting, will have to get that 50 jet.

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Is it a different design than a 450R? If so any way to address the issue? I'm 140lbs so I'm not breaking off the kick-starter any time soon. Bike usually starts on first kick anyway.

I'm a CRF-450X newbie, but from what I've read, the trouble occurs when you let go of the kickstart pedal at the bottom of it's stroke, allow it to spring all the way back up, and it slams against the stopper.

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Is it a different design than a 450R? If so any way to address the issue? I'm 140lbs so I'm not breaking off the kick-starter any time soon. Bike usually starts on first kick anyway.

Well if the plate was upside down all of the rest of this is just minor details :lol: There's a Quickshot 3 already installed and an o-ring mod done by PO so I should be able to tune it pretty well shouldn't I? Other than jetting, will have to get that 50 jet.

The R model is very different. Honda uses some core engineering on the X (based on an '03R) but not many interchangable parts. The kickstater mechanism has a stop plate the keeps the magnesium cases (fragile) from being in direct contact with the steel. That plate bends/fails with normal use, usually during a small kickback.

http://www.thumpertalk.com/forum/showthread.php?t=434373

The Quickshot 3 is problematic on almost all carbs, as it was designed for an earlier version of the FCR CRMX carb. The only way to upgrade the Accelerator pump is to change the linkage spring, put in fresh diaphram and spring, and a 50 leak jet, followed by accurate adjustment.

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Success! Put everything back together, kicked it a bunch to get started, adjusted idle and fuel screw. Now it starts just like my 450R, I literally start it still wearing my Teva Mush flip-flops in the pits since it starts from half-assed kick most of the time anyway.

I can see now how shit gets broken in the kick start mechanism though, before I got it in the ballpark it definitely was recoiling badly a few times and there was some serious back-kick going on that seemed to be strong enough to break shit. I hope it just keeps being nice.

So on the quickshot, do you recommend to just put the stock stuff back in and change the spring and leak jet? Note I'm not racing supercross or anything like that and I'm used to using clutch for throttle so being able to really WHACK the throttle open has no use to me, I just want it to respond well to a smooth but quick roll-on. Thanks for the tips Krannie!

On a different note, 450R seat and tank don't work with 450X radiators. About 15mm off on the lower mounting hole. Son of a bitch. Had to go back to X tank (that pisses me off) and X seat, luckily at least all that works fine with R subframe and airbox.

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I'm a CRF-450X newbie, but from what I've read, the trouble occurs when you let go of the kickstart pedal at the bottom of it's stroke, allow it to spring all the way back up, and it slams against the stopper.

That's a pretty odd thing to do though it definitely shouldn't be breaking shit. Thanks for the info! :lol:

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Damn I just found out that X clutch is not the same as R, son of a bitch! Was hoping to have stuff swappable between my R and X but damn so much stuff on the X is "close but not quite the same".

Anyone know the details on what is different about the X clutch? I have an STM slipper sitting pretty for the carb'ed R model bikes which looks like won't work on the X?

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Damn I just found out that X clutch is not the same as R, son of a bitch! Was hoping to have stuff swappable between my R and X but damn so much stuff on the X is "close but not quite the same".

Anyone know the details on what is different about the X clutch? I have an STM slipper sitting pretty for the carb'ed R model bikes which looks like won't work on the X?

As mentioned before, and in hundreds and hundreds of posts in this forum, there are very few parts that interchange between the X and the R.

You'll just have to accept it.

The X is made with more heavy-duty parts for longer rides.

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So far the triples swapped easy, the whole back subframe and plastics are in from the R bike. Suspension, wheels pegs, controls, air/oil filters, stuff like that does swap over. I'll do some weight comparisons in the next few days since I got both X and R version set up almost exactly the same now.

I appreciate some of the stuff X bike has that R doesn't like the stock light coil, e-start and such, but some other stuff I'd prefer they just wouldn't mess with like clutch and seat for example.

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So far the triples swapped easy, the whole back subframe and plastics are in from the R bike. Suspension, wheels pegs, controls, air/oil filters, stuff like that does swap over. I'll do some weight comparisons in the next few days since I got both X and R version set up almost exactly the same now.

I appreciate some of the stuff X bike has that R doesn't like the stock light coil, e-start and such, but some other stuff I'd prefer they just wouldn't mess with like clutch and seat for example.

You might want to do a search. There have been a dozen or so posts on this subject since 2004, when the 450X was released.

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