2010 YZ450F Issues

Hello All,

After spending the last hour writing a full intro of myself and a review of the bike, since I am the new guy here, the board just wiped it all upon clicking the preview post button, so now I just want to see if there is anyone with the same issues as I and see if there are solutions.

Throttle response - almost too instant, going through bumpy stuff I found that while even making a conscious effort to keep the throttle rolled forward, I was still adding power and lurching when I didn't want to. - I have read that this can be feathered out a bit by changing the fuel mapping?

Starting - this is brutal compared to what I am used to. Even after finding the compression stroke and TDC it still takes 3 kicks or so but here comes the real killer. It will not start if it is in gear and the clutch is pulled in - ***??:cheers: I have to stop and find neutral, then begin the TDC kick procedure. I sure hope this is a "new bike" issue? Any ideas or solutions here?

Getting going -:moon: - So now that the bike is started and running, finally, it has a spot during clutch release where it just magically dies. It doesn't grab and lurch forward and die, aka user error, it just dies. If I am not giving it the correct amount(more than normal) of revs and doing my absolute best effort to release the clutch properly it will just die, then I must start the entire find neutral, TDC 3+ kicks procedure all over again...ugh...

I am having a good bit of buyer's remorse here, something I have never had in my 25 years of riding bikes - what gives? Do you folks have any insight on these issues? Are they solely related to this new bike? Granted I only completed break in, a few heat cycles, and a 15 minute ride afterwards but this is just saddening to me and ruined the experience of bringing it home. Meanwhile my wife just prods the switch on her new CRF230F and is leaving me in the dust before I can even find neutral...

...thoughts? and thanks!

Here's a tip - despite common 4-stroke guidance - ever so slightly crack the gas as you are on the downstroke of the kick. Mine seems a bit hard to start if I don't do this.

Get a little time more time on it to break it in and it will change a bit

Throttle response is all about personal preference, and the tuner which I have for mine allows you to find your desired response.

As for starting mine starts 1-2 kicks cold every time, 1 kick once warm and yes it needs to see neutral.

My clutch felt a bit weird when new but now it feels just like my 08 did. Get some more time on it and I think you will be fine

The manual says nothing about finding TDC. It states' "push down lightly until resistance is felt." That is the compression stroke, not TDC. If you go ahead and try to locate TDC, you will go past it, and this will position the engine almost two full revolutions away from the next ignition event. The idea, just as with the older models, is to position the engine at the beginning of the compression event and kick it through that, past the ignition point, and over TDC to get it to fire and run.

The common tendency in the vernacular to misname the start of the compression stroke as "TDC" when it clearly is not is confusing to a lot of people, and causes a number of problems just like this, even with carbureted models.

Thanks for the insight, I had just assumed that the compression stroke was in fact TDC since all the mags/reviewers have referred to it as such. It was indeed the compression stroke that I am/was kicking it on - turn over until you feel strong resistance and kick.

Strikes me as very odd that a MX bike such as this must be in neutral to start, it's the last thing I would want to try and find while watching other racers pass me by!

Since you're so disappointed, I'll trade you straight up for my lightly used 06 with a ton of accessories installed, including a new rear tire. I'll even drive to you! :moon:

My '06 is hard to start in gear, too, and a lot of other people have the same problem. For the most part, it's due to the clutch dragging enough to slow the kick down. That may improve with age.

As far as positioning the engine at the compression stroke goes, this site is crawling with people who haven't done the auto decompression mod on their pre-'03 bikes yet who insist that "the drill" of finding compression and advancing into it part way is no big deal, and that they can start their bikes as fast as anyone. Now that this one comes out and somewhat requires the engine to be pushed up against compression, it's some kind of huge problem. The truth is that both my '06's start much better that way than not anyway.

You should experiment with the idea offered regarding cracking the throttle open. This is tricky for most people because it requires you to open the throttle only a little off idle and hold it steady while you kick. It will help if you grab the throttle housing with your thumb to stabilize your hand.

I don't know for sure if the 2010 works this way or not, but it's become very standard with EFI in general that when the engine is cranked, their will be a shot of fuel discharged from the injector that is proportionately larger as the throttle is opened farther. But at some point, usually less than or right about half throttle, no fuel will be delivered at all when the throttle is opened this far at RPM's lower than a set speed. This is called the "clear flood" mode, and is done by design so that a flooded engine can be cleared out by cranking with an open throttle, same as with a carb. With a carburetor, there is not enough vacuum to raise fuel from the pilot jet when the throttle is opened at cranking speeds, and the clear flood mode is a way of duplicating that behavior in an EFI system.

Hello All,

After spending the last hour writing a full intro of myself and a review of the bike, since I am the new guy here, the board just wiped it all upon clicking the preview post button, so now I just want to see if there is anyone with the same issues as I and see if there are solutions.

Throttle response - almost too instant, going through bumpy stuff I found that while even making a conscious effort to keep the throttle rolled forward, I was still adding power and lurching when I didn't want to. - I have read that this can be feathered out a bit by changing the fuel mapping?

.

Starting - this is brutal compared to what I am used to. Even after finding the compression stroke and TDC it still takes 3 kicks or so but here comes the real killer. It will not start if it is in gear and the clutch is pulled in - ***??:smirk: I have to stop and find neutral, then begin the TDC kick procedure. I sure hope this is a "new bike" issue? Any ideas or solutions here?

Getting going -:cheers: - So now that the bike is started and running, finally, it has a spot during clutch release where it just magically dies. It doesn't grab and lurch forward and die, aka user error, it just dies. If I am not giving it the correct amount(more than normal) of revs and doing my absolute best effort to release the clutch properly it will just die, then I must start the entire find neutral, TDC 3+ kicks procedure all over again...ugh...

I am having a good bit of buyer's remorse here, something I have never had in my 25 years of riding bikes - what gives? Do you folks have any insight on these issues? Are they solely related to this new bike? Granted I only completed break in, a few heat cycles, and a 15 minute ride afterwards but this is just saddening to me and ruined the experience of bringing it home. Meanwhile my wife just prods the switch on her new CRF230F and is leaving me in the dust before I can even find neutral...

...thoughts? and thanks!

I would try putting some more slack in the throttle, i used to do this while learning to ride 250 2t 's. Its funny though, after riding my YZ250 2t the throttle response of the 450 doesn't seem so bad.:smirk:

If still its still to snappy buy a tuner and remap it.

One of my mates bought one of the first RMZ450s to hit our shores, and it to was very abrupt off idle, but the 08.5 RMZ i had was a lot mellower.

As for the starting, these bikes do get better with age, mine has 18hrs on it and gets better every time i ride, probably because i am starting to get my head around the starting procedure. You basically just roll your leg through the kick stroke with firm pressure.I found the hard way that is easily if you pound the kick start. I have had my bike start when cold while trying to find the compression stroke. My old 08 RMZ450 required a minimun of 3 kicks no matter hot or cold, to me this was acceptable.

I have not noticed any clutch issues, but while i am riding the rpm would not get low enough to notice any issue.( I might try this out to see if if has a problem at low rpm.)

As for starting in gear, i have never had any bike start in gear easily. Even my 2t takes 2-3 kicks to get going. Every 4t i have had has required them to be in neutral to get them going quickly. The has started in gear though, but it nearly wore me out doing so, same story slow kick on the compression stroke.

Its like any new bike, it will take some time to adjust to and figure out.:moon::thumbsup:

Add slack to the throttle. I was reading a review that said they had to do the same thing. It was too responsive to the twist. If its in gear kick that SOB like your going to lose a race give it just a little bit of gas. It seems like all my 4 strokes are a pig when they are in gear. However they will start if you get it spinning fast enough. The drag added by the clutch or fluid on the plates is the problem, make sure your clutch is adjusted correctly too.

I don't understand how adding slack to the throttle will change the throttle response. You are not actually changing how fast the engine accellerates with the addition of fuel/air, you are just adding slop. Once the throttle cable is tight, the same situation of "whiskey throttle" will still be happening. Adding slack to the cables does nothing to change the actual response of the engine. The only true fix is to re-map.

mine starts any where between 1-3 kicks

get the power tuner and you can tame it down a fair bit there are maps posted in this forum now i am ust of riding it now i proberly put stock map back

starting in gear i have not tryed it would more than likley cluch drag there is no switch to tell ecu what gear it is in so it should start in any gear

stalling adjust your idle a little higher i have not had that problem i have noticed that hondas efi stall easy

You should experiment with the idea offered regarding cracking the throttle open. This is tricky for most people because it requires you to open the throttle only a little off idle and hold it steady while you kick. It will help if you grab the throttle housing with you thumb to stabilize your hand.

That helps my 08 start if, on the odd occasion it wont after a few kicks without throttle. The way I do it is to hold the front brake on for support and use your thumb to hold the throttle slightly open.

Also, IMO you should get into a habit of always finding neutral before starting.

curious what bike you are coming off from prior to this?

A programmer will tame it down - new mapping

the TDC issue will be easier after some time on the bike - all 4strokes stink somewhat when starting them in gear....

the third issue is new to me - might have another 2010 blu rider ride it and/or dealer. It should not die unless your revs are way too little....

sorry about your remorse - hopefully you can straighten all the issues out and like what you bought

Another 2010 question: I was practiceing starts today and went back to watch me do them on the video and noticed when I rev the bike high smoke comes out of the head breather tube.Is that normal?

Less expensive than remapping is to buy an adjustable throttle tube. Now you will be able to slow the opening of the butterfly therefore slow the response to you opening the throttle, then the power will feel more manageable.

curious what bike you are coming off from prior to this?

the TDC issue will be easier after some time on the bike - all 4strokes stink somewhat when starting them in gear....

Started on a YZinger, then yz50, yz80, yz 125, mx180, and tt350 - all older Yamaha 2 and 4 strokes - nothing newer than mid 90's - none of which needed to find the compression stroke or wouldn't start in gear with the clutch pulled in. Just pull out the lever and crank it a few times...I haven't ridden in 10 years so I am just getting back into the sport and things sure have changed! :banghead:

I just really need some more seat time and the weather is just too ugly for that right now.

Thanks to all for the comments and suggestions!

I don't understand how adding slack to the throttle will change the throttle response. You are not actually changing how fast the engine accellerates with the addition of fuel/air, you are just adding slop. Once the throttle cable is tight, the same situation of "whiskey throttle" will still be happening. Adding slack to the cables does nothing to change the actual response of the engine. The only true fix is to re-map.

I've been saying this ever since the first reviews came out here. I agree also that fuel mapping may help ( I have no idea about this since I have never done it). I do think that a throttle tube with a modified (softer) pull is a good answer. Josh Grant uses these adjustable pull tubes to lessen his throttle response in slippery conditions and make it more responsive in dry/sticky conditions.

It won't ever matter how much you loosen the throttle cable except that you will twist your hand further to find the "hit". Prior to the hit, however, you will still be flat as you will have applied no throttle.

Started on a YZinger, then yz50, yz80, yz 125, mx180, and tt350 - all older Yamaha 2 and 4 strokes - nothing newer than mid 90's - none of which needed to find the compression stroke or wouldn't start in gear with the clutch pulled in. Just pull out the lever and crank it a few times...I haven't ridden in 10 years so I am just getting back into the sport and things sure have changed! :bonk:

I just really need some more seat time and the weather is just too ugly for that right now.

Thanks to all for the comments and suggestions!

I think this is 99.99% of your problems - the bikes today are no comparison to any of these.....more starting time, more seat time and a little more throttle....but careful throttling

:banghead:

Another 2010 question: I was practiceing starts today and went back to watch me do them on the video and noticed when I rev the bike high smoke comes out of the head breather tube.Is that normal?

temp, oil height may have something to do with this - look at the oil height and color/condition if you are worried

Started on a YZinger, then yz50, yz80, yz 125, mx180, and tt350 - all older Yamaha 2 and 4 strokes - nothing newer than mid 90's - none of which needed to find the compression stroke or wouldn't start in gear with the clutch pulled in. Just pull out the lever and crank it a few times...I haven't ridden in 10 years so I am just getting back into the sport and things sure have changed! :banghead:

Those are all little bikes, except for the mid-size TT350, and it was just a trail bike with a very mild engine tuned about like a typical passenger car. Now you're on a purpose built large displacement race bike with an engine that produces over 110 hp per liter. Yeah, it's going to be a little different.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now