Poor mid range performance....

Took my 08 R for a spin after changing rear tire & handlebars. I coughed & sputtered during hard acceleration. Bike has 4100 miles. Engine is stock with no mods. Bike ran fine last week during a trail run. Pulled air filter & did a test run with the same result: missing on hard acceleration, little mid or top end pull. Ideas on how to check fuel flow to throttle body???? ECU function??? other points to check?

Thanks

Start simple. Bad gas? Buy from a station that is not your normal? It's happened to me.

WRoldman, thanks for the suggestion. I ruled out the bad gas since the gas I'm running on is the same as we used last week when it ran fine. I finally gave up & took to dealer.

Make sure you keep us updated. It is always nice to know what is up.

Yes, be sure to tell us what the problem was for your bike.
Don't be like most people who come on asking for ideas to solve a problem, only to POOF!, never be heard from again. :)

Myself, I'd be double-checking anything that was messed with since the last time the bike ran properly.

Sure hope it's something simple. Post back to us when you can.

Sarah

Good luck with it. And +1 on what everyone else said.

Well I found out what the problem was......... The Exup servo died. Let's see should I spend $245 parts + $100 labor to replace it???? Nope just the impetus I needed to go ahead with engine modes..... Remove the Exup & install the patch to handle the controller, remove the
AIS, install FMP powerbomb, Q4, & Power Programmer, & K&N air filter and open up the airbox. Great timing with FMP 20% discount on 4 cycle parts..... Plainly another reason to do the mods to help out the engine. Now let;'s see how bout the turbo next......... Just kidding on the turbo...

Thanks for your suggestions and help.

bill

Congrats on the fix/finding out

Glad you got it sorted and that you told us. :)

Thanks for posting back...Enjoy those mods!!

Sarah

hamish54 wrote:

Well I found out what the problem was......... The Exup servo died.

Did they tell you why or how they checked it to find out it was dead? Im brand new to this bike, so any extra info would be helpful to me since I dont plan on doing any performance mods to it.

Thanks, beardo

When you turn on the ignition, the ECU sends a signal to the EXUX servo to cycle from stop to stop. If you listen closely, you can hear it cycle. The EXUP servo is on the left side just in front of the rear side panel. Also you may get an error code "17" showing up on your dash display' bottom line when you shut down the bike and turn it back on. Your check engine will also probably come on. Code 17 lets you know the EXUP is not working or is shorted out. I hadn't planned on doing any mods either until the dealer told me the valve was bad. I've pulled the EXUP valve but not installed the eliminator (http://www.thumpertalk.com/forum/showthread.php?t=687498) yet so I'm getting the error code. Also installed FMF Powerbomb header & Q4 silencer, opened up the airbox, and removed the AIS. Engine is still running rough on acelleration. So far I've seen no negative results from others who upgraded their exhaust which disconnected the EXUP valve. I will be installing the FMF Power Programmer. Hopefully remapping the ECU will solve the stuttering engine problem.

Everyone else with more experience, please chime in.

Bill

I bet you'll like that programmer big time; you need to get one as soon as you can, in my opinion. I could have kicked myself for waiting so long. Did you use a dremel or some such and open the airbox way up? Holler back and let us know if you get the rough running sorted. 99 cent resistor trick is still working well for me:

http://www.thumpertalk.com/forum/showthread.php?t=849081&highlight

Sarah

Airbox mod: Followed HighFive's suggestions on his site http://www.wrrdualsport.com/. Pulled the top of the airbox. Cut out the divider in the snorkel and the bottom of the snorkel into the airbox. Found a great use for the Flapper....... glued it over its servo mounting hole on the snorkel top. Perfect place to mount the Power Programmer.

FMF Power Programmer: Installed but couldn't get bike to start except when the unit's ground wire was disconnected. Techs at Dobeck, the manufacterer of the unit have been great in diagnosing that this unit is defective. Shipping back to them tomorrow for a replacement unit. Apparently this unit has faulty programming. I'll let ya'll know how she runs once the new map is installed.

Bill

Man, sorry to hear that on the programmer. I wish they'd go ahead and send you a new one rather than wait for yours to return. If your weather is like ours though, no big rush.

Sarah

Well an update on "Poor midrange performance"...... I was wrong about the FMC Power Programmer. It wasn't defective at all, just needed to ground to the frame instead of the negative battery terminal. Programmer worked great thanks to the great help I received from Dobeck. Their support is fantastic.
After getting the programmer to work, bike still skipped & jumped, so took it to North Tx Yamaha in Lewisville. The Ex up valve diagnosis was from Yamaha-Suzuki of Tx. That will be the last time I take a bike there. They kept promising they would look at for a week. True the Exup valve was not cycling, but it was not the problem. Bill for exup diagnosis- $105. Guess what it was????? Chris at NTx Yamaha diagnosed the problem in 15 min.... Would you believe a worn out chain & rear sprocket???? Bike has 4100 miles. Sprocket doesn't look worn. Chain measured within tolerance. However, in gear, hold the rear wheel off the ground and she skipps like a rock across the water. NTX labor charge- $45. Installed new chain & sprockets, no more skipping. Oh well at least this gave the impetus to go ahead with the engine mods and as those of you who have done these mods, what an improvement.

You had that rubber ring on your rear sprocket, didn't you...others have had that trouble too. Too bad you couldn't have found that out sooner, got yourself a different rear sprocket and would have been good to go. Figures. Glad you've got the bike back and raring to ride. It sucks being without a bike.

Bill,

Did the shop sell you the same sprocket with the rubber ring? Proper chain tension is a fine line with that crazy thing...

But if you bike is like mine, the programmer is a huge benefit regardless.

Sarah

Does the 'rubber ring' sprocket come stock on the bike?
Just on the R, or the X too?

Picking up new X today, and I'll think very seriously about changing out the rear sprocket soon if it has the 'prophylactic' sprocket...

It came on the 08's. Mine is an 09 and didn't have it.

ya you're right finally getting rid of mine...it's a dampner for the vibrations,the front 13t has it too.changing to the 09' 43t(considerably cheaper) next week and a 12t on the front.should be sweet!
got a pic. thou...not bad for 22,000ish km...a new chain went on last summer but not too bad ya
john

Sarah,

I went with a Supersprox Stealth Rear Sprocket 48 Tooth , Renthal's 13, and RockyMtn ATV Primary Drive 520 ORH Gold X-Ring Chain . Also experimenting with a 14 up front, but I'll probabley stay with the 13 except when I want to do slow tight singletrack. Then I drop back to the 12 tooth.

Maybe it's all in my head, but the bike seems to keep pulling stronger with each ride since doing the engine mods.

billl

Glad you've got things sorted out, now just enjoy the ride! Thanks for the details on the sprockets and chain, I'm shopping, too.

Sarah