New and I need a little help

I just bought a 2010 yz450f the bike has been set up with a enduro kit. I took it on a trail ride yesterday and it was misserable. at idle in 1st gear the bike was just to fast. I would constanly have to clutch it and must have killed it 10 times. The gearing has obviously been changed to be more street suitable than trail. I live in Tahuya WA and ride tight single track 90% of the time. I bought this bike with the intentions of having it be a 4 season bike as I have also purchased the Timbersled kit for it. I guess what I need help on is what shoud my front and rear sprocket be? I like to be able to go slow in first and realy lug it down. I have read alot about these tuners and sounds like I should get my hands on one but I can not afford that until next year. I am new and tried to search this bu had conflicting reports. I am not sure that it matters but the bike has a full FMF 4.1 on it. I also noticed it's super jumpy off idle but I realize I am not fixing that issue without a tuner, so I'll learn to live with that for now.

THanks Jason

If any of you are local to me you may know the bike it was a race bike for Leon Capps he recently turned it into a enduro. It was at Brother Powersports in Bremerton. I

Sorry I am such a bike moron I have been riding a clapped out XR400 for years, this high power bike stuff is all new to me.

oh I think the gearing now is 14 front 47 back. I did get a 13 front in a box with the bike I have yet to install.


Rather than start a whole new threard for me. If anyone has a comfy seat please share what it is, mine is like a rock and I sit down a lot I am 6 ft 250 lbs. What on the market has the most squish?

Also I have no idea how to set up suspention properly if somone could link me to a good place to learn that it would help. The guy that owned the bike was lighter than I so I know I need to change some things/

I think the gearing now is 14 front 47 back.

Stock is 13/48. No wonder you're stalling it.

So you think changing the front sprocket back to a 13 will make a big diffrence? I can't imagine one tooth on the back would be significant, but I have never messed with sprockets. I have to buy a 12 tooth for my timbersled setup as well.

one tooth at the front is equal to about 3 at the rear. Yes, it will make a big difference.

If you want tight woods gearing, you could go for 13/50 -but I imagine that would make it less well suited to the street.

Edited by cereal killer

Okay It will run well over 90 on the street topped out now. I have no need for that, I use the street legal part just to run loggin roads or access the trails more easily no plans on commuting on a MX bike ;) . I think I will try the 13 tonight and if it's not a what I need I'll go ahead and add the 50 rear as you suggested. Thanks alot!!

13 helped, gunna need to go to the 50 as well I think. I am used to the low end grunt of my old xr400 were when I would approach a slimy root on a hill I could just chug up to it snap throttle get back off and let rear tire chug over. I know this bike is not intended to be a slow technicle trail type bike but I intend to make it that way as much as possible as I am no racer and intend to just enjoy trail riding in the (off season) as it's main use will be as a timbersled.

Nice bike.

Get the 13/50 sprocket set and it'll be a lot better. Although, the gearbox ratios aren't going to be suited to trail riding like your old XR400. That's the price we pay for buying a MX bike for trail riding. I will eventually be attempting to swap a WR gearset into my YZ. As when that will happen, I've no idea.

The tuner is great, try to find a used one on ebay. I got mine for like $150. Took a few months to get it, but worth it.

For suspension, you NEED to get it sprung for your weight and probably revalved as well. For us guys that weigh more than average it is the biggest improvement you'll make to your bike.

edit: You may want to invest in the GYTR Off Road flywheel at some point too. That'll help some with the low RPM chugging you want.

Edited by WouldsAssassin

Another wee trick I did to my '11 450 was bring the idle up a bit. It will "push" a little coming into corners but you will adjust to it, reduces stalling a lot as well. I run 13/50 gearing.

Next mod I am considering is a G2 throttle to smooth the off closed throttle hit , then I may be able to load a more aggressive map and just give it a good twist when I need some real punch.

Was flipping through the WR450F section and found a link to this article from regarding mapping for the WR450. While not directly related to the YZ some of the mapping settings recommended for the WR may work for those of us that ride trails or off road. I don't know about you but I kinda feel a little like I'm taking stabs in the dark with the tuner. For me, getting a "base map" from another source and tweaking has worked pretty well so far.

You are free to try whatever you think will work, but I have to point out that the base map (9 zeros) in the ECU for the WR is almost certainly different, perhaps very different, from the base map in a YZ, so "+2" isn't going to necessarily mean the same thing on one bike as it does the other. In fact, there has been at least one base map change just in the YZ450. Note that the "woods" map listed for a YZ ( LINK ) is considerably different from the one listed in the article you linked to.

Apart from that, there is the valve timing (cams) of the two engines, which is very different.

Personally, I would not expect the WR maps to be useful in any way for a YZ, and I'd use caution in trying to run one of them.

Thanks Grey. I hear what your saying about the two bikes but in terms of tuning with the GYTR tuner we're just adjusting fuel and ignition based on the factory map (all 0s in all cells of the tuner).

Since none of us here are experts on FI tuning with the GYTR power tuner. For me it helps to read what different sources are doing and apply that to what my intended purpose is. I used the YZ woods map and didn't like it. The YZ map adds too much fuel in the RPM and throttle range I spend 90% of the time in. Needless to say it cut my riding range significantly. There has to be a better way. Both maps modify the ignition but the WR woods map cuts fuel to make it more manageble. The WR is known to be fueled lean to begin with. Hey maybe it'll be better, only one way to find out. We all tune our bikes at our own risk. User beware, right. It wouldn't be any different with carb jet suggestions. I would have to think it would be harder to "tune" an engine problem with the Yamaha branded electronic tuner than it would by swapping jets and turning fuel screws with the same level of tuning ignorance.

I would have to think it would be harder to "tune" an engine problem with the Yamaha branded electronic tuner than it would by swapping jets and turning fuel screws with the same level of tuning ignorance.

When you could load and try 3 maps in the time it takes to change a needle setting? I disagree.

What I'm saying is that if you find a suggestion to bump the ignition +4 for a low emissions trail dog and apply that to a YZ that may already be as much as 8 points farther advanced, you could end up with trouble. The two engines are very different in stock form.

It just so happens that I have spent a considerable amount of time "mapping" both the new FI Wr and FI YZ , Grey is correct , the mapping required for both is radically different. The WR requires a "CO" adjustment to begin with +4 over stock is the best all round setting. Yamaha Australia has recommended settings to try on the WR, they are an excellent starting point.

Until November last year I was a Yamaha mech here in NZ so this is from trained experience.

I'd agree that the mapping for the WR and YZ are radically different. However, using the GYTR Power Tuner, we the end user have no idea what the true fuel flow, air:fuel ratios, CO, ignition timing etc are. With the Yamaha branded power tuner all we can see are 0s, 1,2,3,4,5...or -1,-2,-3,-4,-5.

If it is recommeded for one bike to smooth or increase the power delivery by selecting -4 and +2 for a group of cells it could work for another. It is not possible to load a Yamaha base fuel and ignition map for a WR onto a YZ with the GYTR Power Tuner. It could be possible with other aftermarket FI tuners, but not with the Yamaha tuner. Let's not confuse what we are capable of with the simple GYTR Power Tuner. We can only adjust the base mapping up or down from the "0" setting, that is all.

Now, when I say it would be easier to re-jet an engine problem than to tune an engine problem with the GYTR power tuner is because Yamaha has no control over what we the user can do do with a carburetor and a handful of jets. However, Yamaha built the engines, ECUs, and Power Tuners. Well maybe not built them, but Yamaha has full control over what we could do with the tuner. I'd have to think the legal department of Yamaha Motors would not allow a device to be sold that could make it possible to tune an engine problem. I could be wrong, it has happened before. I am not wrong at saying the recommended Power Tuner settings for the WR could work for the YZ, could not will.

You are 100% correct , a Wr map can be loaded into a YZ and vice versa. It is the outcome that will vary. Regardless, the tuner is a very good and versatile tool.

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