Low Speed Issue

[Tom of VA]

I am the second owner of a 2003 FJR with only 2800 miles. It looks brand new. I have only one problem. When I ride and maintain a constant speed of 35 or under the engine seems to have a hard time dealing with the small throttle openings. The ride is a little jerky.... The bike seems very happy under constant load or decel, but consistant low speed/low rpm operation is not confortable. It's hard to discribe, it feels like the engine is bouncing between load and the inertial force of coasting. I haven't spoken to the dealer about it yet, but if anyone here has expirienced this it would help me when I go to the shop. Maybe a throttle positon sensor, injector sync?? Just to make sure it wasn't me, I took my R1 out for a spin and couldn't reproduce the same kind of rebounding feeling. After riding the other bike it feels even apparent now. Ideas anyone??

help appreciated,

Tom

 

[Tom of VA]

oops, I see I posted this in the wrong spot.

 

[Windjammer]

Make sure the throttle has less than 5mm rotational play at the twistgrip. Keeping play to a minimum seems to help. I've also noticed that keeping rpm over 3K helps when cruising through towns - so gear selection is important too. I think it's just the nature of the driveline, I bought new '05 and it did the same thing right out of the box. But the above will help, and if they don't then maybe something needs repair. I'd check driveline lash first.

 

[Tom of VA]

Windjammer,

Thanks, riding in a higher rpm range seems to change things up a little, but it definitely doesn't feel right. The driveline feel just fine to me though. This is not the kind of jerk you get from slop in the drive train. Maybe another rider wouldn't even notice it.

Thanks,

Tom

 

[jbay]

My bike was exhibiting all the low speed quirks you guys are talking about. I always wanted to run at slow speeds through towns in 4th or 5th to hide the throttle abruptness . Did the Barbarian Mod and raised CO settings 5 point ,some raise it 7 . The bike has no issues at any speed , any gear or any rpm. The darn thing just comes to lean from the factory. It's the same as putting a jet kit in a carbureted bike , which I have done before to eliminate same problems. Try it you'll like it. :good:

 

[ionbeam]

The Barbarian Jumper Mod helps or fixes most of the surging cases. The BJ Mod has the advantages of being cheap, relatively easy and it is completely reversible at any time. (Be sure to write down the starting CO offset numbers.)

Should that not work then the spendy PCIII with one of the available fuel maps almost certainly will.

My FJR did not take to its BJ very well and ran significantly worse. The PCIII made it livable enough that I decided to keep it. YMMV.

Alan

 

[Tom of VA]

You know, maybe it is too lean. I notice when I start off and the bike is still cold, it feels better and I think the jerkness comes as the engine gets hot. Hotter usually means leaner. I'll pay more attension next ride.

 

[Centerline]

Fortunately my '05 edition does not exhibit any of that quirkiness you describe at very low speeds. It has always been silky smooth at all rpm ranges from idle trolling in first gear right on up to max speed. I usually warm the beast to two bars before riding, although sometimes I will idle away in first gear after one bar shows and stay at idle until two bars appear for temperature.

To reiterate, my beast is quite well mannered trolling in first gear etc.

 

[Tom of VA]

I bought a PowerCommanderIII and that cured the factory lean mixture issues. Nice and smoooth now.

 

[torch]

Another thing that may help is a fresh, clean air filter. Some people have found the low speed surge was dramatically reduced after installing an aftermarket free-flowing air filter (K&N, UniFilter, etc.) The FI system calculates air mass from air pressure sensors before and after the filter and I suspect it has trouble getting accurate readings when there is little difference between them (as with small throttle opening situations).

 

[Bike Effects]

It's Power Commander time!