Stuttering at 7000 rpm

[nickodemon]

I took the bike for a blast today and noticed when i snapped the throttle open the bike hesitated and wouldn't rev passed 7k i only tried it once as i was nearly home. I also noticed on same run earlier in the day that when i went to pull in and stop the bike hesitated again at low revs... I think i better change the plugs for starters and work from there. I have put some redex in the tank to possibly flush out gummed up fuel in the carbs. The bike had only done 800 miles in the last few years..

[Falcon 269]

This the same one that's been having EXUP problems, Nick?  Also, I assume nothing could be getting sucked into the air intake ...?

[nickodemon]

I cleaned every connector and covered with dielectric grease. Two of the spark plug caps were not pushed down onto the plugs and i found this.... Took the bike out for another spin and it's pulling fine with no stuttering. Will be ordering a new air filter me thinks

[nickodemon]

This the same one that's been having EXUP problems, Nick?  Also, I assume nothing could be getting sucked into the air intake ...?

Yeah mike it's the same one that had the exup fault code (fixed now ) " I assume nothing could be getting sucked into the air intake ...? " Nothings getting sucked fullstop with the state of that air filter

[Falcon 269]

Sheesh, that's like a 10-year old Hoover bag!

Problem solved, I reckon.

[nickodemon]

It actually felt like i was emptying someone elses hoover. Yuk... The only issue i have now is it doesn't like ruts in the road or white lines. The tyres have loads of tread left on them, so i will need to check if steering head bearings are tight or notchy. Anything else cause a bike to behave like that?

[Falcon 269]

Tyre pressure, wheel alignment, suspension settings.  You're in the right area with all of these.

[nickodemon]

What setting do you have on your r1 front end? I have a 5pw on this one.

[NorthWestern]

I always find as soon as the rear tyre starts to square off white lines push the bike around when filtering

[nickodemon]

Tyres have done very few miles. It may be the tyre choice    It has metzeler sportec m3's fitted..

[NorthWestern]

It only has to be slight. Run your hand across left to right, you'll feel it even with lots of meat on the tyre. I doubt it's the tyre choice and the m3 are good.  I've run allsorts on mine, qualifiers, race tyres, tourers, wrong width for rim and nothing causes problems really until squared off.

[nickodemon]

Tyre has definitely not got any flat spots here is a pic.. The previous owner had said the handling was poor until he fitted the new tyres, so it must have another issue. I checked the wheel bearings, swingarm bearings and steering head bearings and they all seem fine.

[NorthWestern]

Bent frame or forks?

[nickodemon]

I will check wheel alignment. It appears to improve once the tyres have warmed up? If riding on a good surface the handling is good. It's only if there are ruts in the road or white lines

[NorthWestern]

Yeah ruts and paint lines. I only suggest squared rear because I had the same thing. Felt like someone was kicking the bike from the side.  Fresh (same model) tyre sorted it until  that squared then again it happened. The front affects it it but not as much.  I replaced the rear shock to a bmw s1000r then front end from standard to r1 then put heavier springs in front and it stayed until I replaced the tyre. That's why I doubt it's a setting. 

[nickodemon]

I might swap the wheels with my standard one to see if it improves.. It has maxxis tyres

[nickodemon]

Right. I went over the bike with a fine tooth comb and couldn't find anything, so i remembered that the last couple of days when taking the bike out there was a slight scraping sound (like stones caught in the rear tyre tread. Upon further investigation the shape of the hugger (puig) about 3" from the end is very close to the tyre. I touched the hugger and rotated the wheel and hey presto there was the exact sound! I looked under the hugger and it's worn at one point. I then checked the tyre at the same area of the wear mark and there is a very small flat spot just off centre. I will change the rear wheel tomorrow and see if that is the problem

[nickodemon]

Small update.... I have swapped rear wheels with the standard fazer and they both have 4mm tread. the gap between the top of the tyre and the hugger is much bigger. Looking at the profile of the tyres the maxxis has a much larger footprint and is not as tall. I don't know if the small flatspot just off centre of the metzeler is making it handle strangely, but the profile of the metzeler is quite steep and considering the bike sits lower at the front because of the r1 front end it may just be that not enough rubber is making contact (slippy over white lines) I will change the front wheel next day or so and take it for a spin when dry to see if its tyre related

[nickodemon]

I Changed both wheels and took for a spin. It is much improved. The real test will be when it's damp. I went over several ruts in the road and it seemed fine, so wet weather test next.