Solved - rough running on 05 Gen 1 1000

[Nellog]

I've seen posts about this before, when looking for clues to the low revs rough running problem I've had on my Gen 1 1000.
I found a wealth of information and advice on here! All very useful but most beyond my capabilities to deal with. Being methodical by nature, I tackled what I could - checking for loose leads, leaking fuel, signs of fuel pump failing (simply listened for intermittent running), operation of Exup. All to no avail.
Delving deeper, I struggled to take out the only plug I could get to - no.1. It was in a right mess (2.5mm gap!). Aha! Solved it methinks. A clean up and reset to correct gap changed nothing.
It was disappointing to say the least - the bike has what appears to be a fsh, and was serviced only a few hundred miles before I got it. Clearly, the servicer didn't bother with the plugs (and what else, I wondered). Oil was clean as a whistle, so I'm guessing that's all that was done.
After a deep breath and consulting the bank balance, I bit the bullet and took her in to George Petch's for a full service and a request to please sort out the rough running if the service doesn't solve it.
Bingo! All four plugs buggered and carb no. 3 a long way out of balance. She now runs like a dream. Hats off to Petch's for a first class job and great debrief on the condition of my bike (very nice was how mechanic Mick summed it up  )
My point here is this: Check out the simple things first, don't be afraid to ask for advice and opinion and be wary of blindly believing the service record on a bike new to you.
I read loads of stuff that could be wrong - most had huge £ signs flashing before my eyes. Take heart that it may be something less sinister.

[roxburd]

Thanks for write-up, Nellog. Good to hear stories. What precisely were the conditions and symptoms of your fault? My fault is this - under heavy acceleration the engine produces less than full power and then there's a step-up as full power comes in. I can't honestly say it's running *rough* as it doesn't feel or sound particularly rough. But I know there's a fault because of the surge in power after 0.75 seconds or so. And the surge is so digital (binary - not gradual at all) that it seems to me most likely to be electrical. However, when I checked my records it seemed the bike was in desperate need of a service so I stripped her down and I'm currently doing a full service - valve shims at the moment. But carb balance next. You've got me thinking about the EXUP too though - I suppose if that were sticking it would explain the sudden step up in power when it flicked into the correct position... do they actually move that quick?


Still, I'll get her back together and go for a test run - if it's still there I'll have a look at the EXUP.



Cheers,
Dave

[unfazed]

Agree entirely, start with the simple things first, and be methodical you would be amazed as to how many, have taken off carburettors and cleaned them, when the problem was a dirty air filter

Never assume the obvious has been done
 

[PaulSmith]

Removing the AIS system will make changing the plugs much easier and there are plenty of threads around on how to do it, but you will still need the Yamaha spark plug tool from the bikes tool kit. It bends in the middle in a way that makes sense when you see it. With that tool, it is still possible to change all the plugs with the AIS still in place though number three is a pig.

Dave, a sticky EXUP valve or cable would cause exactly the symptoms you describe but also make sure there is nothing under the seat that could partially block the air intake. 

[roxburd]

Dave, a sticky EXUP valve or cable would cause exactly the symptoms you describe but also make sure there is nothing under the seat that could partially block the air intake.

Paul, I've cleaned the air filter as advised in Haynes manual... filters I've service in the past haven't been cleanable so I've just replaced them. Does cleaning by vacuuming them out rally work!? Or should I replace it?


I guess I can bung it all back together and replace it as a first item in the next phase of work if the fault's still there...

[PaulSmith]

The filter itself should probably be replaced every second or third service unless you have already upgraded to a K&N style cleanable filter. The point I was trying to make though was not about the filter itself but about the entrance to the airbox. if you have waterproofs, spare gloves or anything else under the seat that can partially block the airbox intake, it could cause the hesitation you have described.

[Nellog]

Roxburd. I have to say that, after adjusting the pulley cable on the Exup (initial indication of Exup fault on the speedo - 0 to 7000rpm), the fault persisted. I was impressed how the Exup operates directly proportional to the amount of throttle given - but it moves gradually rather than a sudden leap open/closed. It can be heard snapping back closed when I hit the kill switch. I didn't notice any change in performance after this adjustment. Given the state of my plugs and balancing, though, it's no surprise.
The signs and symptoms I got before any remedial work were:
Difficulty starting (not an Exup fault symptom, I understand),
Uneven tickover,
A brief delay in engine revs pick up when revving her up (it was possible to twist and release before the engine revs picked up!),
Holding the throttle open, she ran as rough as a bag pf spanners until eventually picking up and screaming,
Intermittent pick up from low revs (static and moving off), and
Scarily low power, jerking and running on three sometimes, at low revs at any speed.


Now that's all done, I've just noticed the Exup warning again. Grr.. It's coming out this time - the slack cable was obviously not the only thing that needed doing.

[Billy Balthorpe]

Blocked pilot jets? Sounds right, poor low speed running, then whooooosh as the revs go beyond 4 or 5 k? I run my Fazer with no exup valve at all, the power under load is obviously lacking under 2K, but once it gets above that it flies. With care you can make it drive at less than 2K, but it takes care and you have to pretend you have a set of fussy race flat slides fitted.
My exup valve was stuck closed when I first got the bike and the low speed running was not affected at all, just no zzzzip at the top end.