FJRiders.com

Greetings; I have a rough throttle response from 1000 to about 3000 rpm. Once the engine is at operating temp and I slowly roll the throttle from 1000 rpm through to around 3000 rpm, the engine manifests hesitation (slight delay) and some roughness. When the rpm reaches around 3500 rpm or so, the engine sort of takes off and races up to about 5000 rpm. It's like the engine gets ahead of the throttle.

Bike is a 2008 with 4000 miles. I've owned it for only 400 of those miles. I've had several tanks of 91 octane fuel through it so far. The throttle response is very sensitive and difficult to get a smooth rpm increase at the lower rpm's. The bike tends to want to lurch when shifting down as I get down to the problematic rpm area and try to accelerate smoothly from that point but it's difficult to do with the rough throttle. It's not severe and dangerous, just annoying and it affects my ability to ride smoothly. I've taken to shifting at higher rpm to avoid the trouble zone.

I've checked the throttle body sync with a dial type gauge and it appears to be spot on. All TB's are precisely synced with the #3 standard TB. The spark plugs were pulled and the gap was per spec and all had the same very light tan color. I replaced with new plugs anyhow just to rule out any possible problems. No change with throttle. I inspected the air filter and it is clean. Plenty of light shines through and I blew the element out with compressed air just to be sure. The battery has not been checked. It is the original factory installed battery. The previous (original) owner kept the battery on a tender at all times (when parked that is). Any ideas?

Copy down the vin# and check with a dealer to ensure all the recalls have been done.
I'd check the TPS via diagnostics to start off with, also check for any error codes stored in history.

If it were a 07, I'd suggest that it had a crook ECU, a fueling issue that was a recall with the 06/07 in the USA, but wasn't in Australia.

While I'm not ruling out that there may be an issue
I think your just lugging the engine.
Mine never pulled well below about 3500 RPMs.
The FJR is more sport bike than cruiser, try riding it
more sportingly.

Aside from that, there may be some merit to pulling
the injectors and having them cleaned.
They could be clogged from lack of use.

Since it's 7 years old and only has 4000 miles, it's set idle most of its life so it could very well be a gummed up fueling system.

Run some techron through it for a few tanks and see if it helps clean the fuel system up. IMO that's one of the best fuel additives out there.

Put the right amount of techron into a tank of gas, run it nearly dry over the next couple of days (in one day if you have the time). Then put some more in and fill up with regular (the FJR doesn't need premium and it's a waste of money as well as burns less efficiently in the FJR). Run that tank down as in as short a time as possible again. Often, in 2 or 3 tanks, the techron will make a noticeable difference as it cleans the injectors and lines from varnish.

!!!! What they said. Lot's of guys complained about throttle response on Gen II's but you just may need to blow the cob webs out of it. Just to add to what Ken said, check to see if it had been Barbarian'ed. If so, you might want to bring is back to stock settings then re-adjust later.

Check the air filter too. If it sat for a long time there may be critters or remnants in there.

...When the rpm reaches around 3500 rpm or so, the engine sort of takes off and races up to about 5000 rpm. It's like the engine gets ahead of the throttle...

A vacuum leak can cause the roughness and the 'zoomie' feel of the engine.

Someone that installed a G2 aluminum throttle tube and throttle pulley compensator can make a normal, non '06 bike behave just like that. The G2 was intended for just the '06 to fix Yamaha's bad engineering decision to put a non-concentric throttle pulley on the throttle body. If it is put on any other year FJR the G2 throttle tube makes the engine RPM advance faster than the rate of twisting the throttle grip. Dunno why a lot of FJR owner put the G2 on other year FJRs but they did. Some filed down the round profile of the throttle cable pulley on the handlebar to make a slight tear drop shape which causes the same out of synch situation where the engine RPMs climb at 120% the rate of the throttle twisting rate. Looking is free. Aluminum throttle tube is wrong (as opposed to bad), and any shape other than round is wrong for the throttle cable pulley on the handlebar.

Queensland Ken wrote:Copy down the vin# and check with a dealer to ensure all the recalls have been done.
I'd check the TPS via diagnostics to start off with, also check for any error codes stored in history.

If it were a 07, I'd suggest that it had a crook ECU, a fueling issue that was a recall with the 06/07 in the USA, but wasn't in Australia.

Good idea on the recall check. I'll do it. What is a "TPS via diagnostic" thing? Are error codes viewed from the instrument panel, or is a special code reader thingy needed? Thanks for the comments.

SLK50 wrote:While I'm not ruling out that there may be an issue
I think your just lugging the engine.
Mine never pulled well below about 3500 RPMs.
The FJR is more sport bike than cruiser, try riding it
more sportingly.

Aside from that, there may be some merit to pulling
the injectors and having them cleaned.
They could be clogged from lack of use.

I am trying to keep the rpm up more. I feel the rough lower section of the tack shouldn't be so hesitant and rough. It's not as I've said, a real bad thing, but its a troublesome annoyance. I'll try that Techron that another member suggested. You never know I do tend to treat it like a sport bike. I'ts difficult not to as the power is extreme and it sort of feels and looks like a sport bike I've had it to over (a really high number) on a straight stretch of road. It got very fast, very fast. An amazing machine.

Bounce wrote:Since it's 7 years old and only has 4000 miles, it's set idle most of its life so it could very well be a gummed up fueling system.

Run some techron through it for a few tanks and see if it helps clean the fuel system up. IMO that's one of the best fuel additives out there.

Put the right amount of techron into a tank of gas, run it nearly dry over the next couple of days (in one day if you have the time). Then put some more in and fill up with regular (the FJR doesn't need premium and it's a waste of money as well as burns less efficiently in the FJR). Run that tank down as in as short a time as possible again. Often, in 2 or 3 tanks, the techron will make a noticeable difference as it cleans the injectors and lines from varnish.

I will do this for sure. Thanks.

OldButNotDead wrote:!!!! What they said. Lot's of guys complained about throttle response on Gen II's but you just may need to blow the cob webs out of it. Just to add to what Ken said, check to see if it had been Barbarian'ed. If so, you might want to bring is back to stock settings then re-adjust later.

Now this thing called "barbarian'ed", is this a legal and moral thing? I'll check for it once I know what it is, but I asked the original owner whom I purchased the bike from if there were any aftermarket stuff on it and he said no. I didn't want a bike that had a hundred different things done to it. I wanted purely stock.

Intech wrote:Check the air filter too. If it sat for a long time there may be critters or remnants in there.

I did. Looks really good and clean.

Hi, a bit awkward if your not familiar with the bike, but:

Have the engine stop switch OFF
Press & hold in the Select and Reset buttons together as you turn the key to on for 8 seconds
A screen will apear that reads "d1AG" or "C0" then release the buttons.

Press the "SELECT" button aagin for the diagnostic mode "d1 AG".
Press Select and Reset again for 2 seconds to enter diagnostic mode values.

Use select or reset to toggle up/dn the diagnostic codes

Diagnostic 01 + TPS should be roughly 15-98, turn the throttle very slowly and the count should increment by 1 at a time
Diagnostic 60= fault history, grab a pen and copy down, fist fault error is the latest
Diagnostic 61 = clear the history, turn the engine kill switch on/off

The Barbarian Mod is something you want to look up yourself. Been a long time since I monkeyed with that and my 14 runs great without messing with it. It is done similar to the diag's that Ken explained except on US models you have to use a jumper. You can get at the CO level though the diag's to make adjustments to the CO levels. Lot's of guys did it on Gen II's. I did but didn't see much of a change on my bike. The reason I suggested it was, IMO if you have something amiss, you need to bring everything back to baseline stock and start from there. If someone adjusted the CO levels, who knows what affect it had or has.
http://www.fjr1300.info/howto/jumper.html
http://www.fjr1300.info/howto/co_adjustment.html

If someone did the Barbarian Mod the OP will see the CO screen when entering the diAG mode. If there is no CO screen then the Barbarian Mod was probably never done. There is the way outside chance that someone did the Mod, changed the CO then pulled the jumper.

People only guessed at the CO settings, almost nobody did it correctly by putting bungs in the head pipes and using a emissions tool to set CO settings correctly. The primary benefit of the CO adjustments is to create a slightly over rich condition which takes the edge off the throttle response due to very mild bogging.

Thanks for the ideas everyone. I'll run some Techron through this Saturday as I'm planning a day-long ride. Looks like pulling diagnostic codes is straight forward as well as determining if the barbarian mod was performed.

ionbeam wrote:If someone did the Barbarian Mod the OP will see the CO screen when entering the diAG mode. If there is no CO screen then the Barbarian Mod was probably never done. There is the way outside chance that someone did the Mod, changed the CO then pulled the jumper.

People only guessed at the CO settings, almost nobody did it correctly by putting bungs in the head pipes and using a emissions tool to set CO settings correctly. The primary benefit of the CO adjustments is to create a slightly over rich condition which takes the edge off the throttle response due to very mild bogging.

In the time of the 06-08's it seemed there was a new cure for the evil throttle response issue every week or so. I did the Barbarian Mod and a bunch of other items to cure boredom and curiosity issues more than to fix a problem with throttle response. IIRC, once the jumper was in you could try "cut and try" all you wanted, but I didn't see any real impact for me. The only reason I brought it up was so many guys tried it on those bikes there was a chance that the OP might have it on his bike.

From what I have gathered, this throttle response issue was not a rare thing, but fairly common over several model years. Also, there is not any one fix that handles totally the problem, and that I will probably have to live with it as it was unintentionally built into the bike at the factory due to a design flaw. Sound about right?

Nope. 2008 and up bikes were fixed of throttle issues. My '07 had never been bad. Kept it in check with properly adjusted throttle cables. Many installed a Power Commander III or IV which seemed to be the best fix. That wasn't really necessary on the '08s, so no idea why yours is giving you issues.

My suggestions: Adjust your cables. Be sure a G2 Throttle tube isn't installed. Do a Throttle Body Sync so you're sure things are lined up. Bring your idle to 1100rpm. If none of that helps, try a Power Commander. Something is going on that shouldn't be caused by the factory.