New can fitted,poor low rpm response

[robbo]

First ride out today since fitting a link pipe and can, in preparation for getting Ivanised at the end of the month. Noticed that the engine bogs down below 2000rpm, having a poor tick over and doesn't run clean till about 2500rpm.Is that to be expected, or has another problem surfaced coincidentally at the same time. Your thoughts and suggestions appreciated.

[stevegixer]

First ride out today since fitting a link pipe and can, in preparation for getting Ivanised at the end of the month. Noticed that the engine bogs down below 2000rpm, having a poor tick over and doesn't run clean till about 2500rpm.Is that to be expected, or has another problem surfaced coincidentally at the same time. Your thoughts and suggestions appreciated.

Had a stubbie can on mine with no probs at all buddy.
Changed it to a stubby akro ( copy) still no probs.
I don't have a problem at low revs but try to keep it above 5k & it should be fine buddy 

[robbo]

Hi Steve,
Do you have a jet kit on your bike. I just wondered if the normal stock fluffiness low down is magnified when a free flowing can is fitted and hopefully this will be remedied when Mike works his magic. It's fine at 5k, but that's a bit over the top sitting at the lights in the High Street.

[unfazed]

Put the old exhaust back on and see if the problem is still there

[PieEater]

Mike would be able to confirm but I believe that the stock fuelling is quite lean especially at low revs so it's possible that a more free flowing exhaust has made the symptoms worse and so more noticeable, especially if you're running without a baffle. I experienced something similar before Mike worked his magic on my bike but this happened not after I fitted my Fuel end can but a few weeks afterwards when I fitted a  K&N filter as well. So from my experience a decent aftermarket end can shouldn't have this affect but if you've removed the baffle or have an aftermarket filter the already lean fuelling may have become too lean.

As an aside have you serviced your EXUP including checking the cable tension recently?

[Falcon 269]

Put the old exhaust back on and see if the problem is still there

Exactly.  

It is probably related to the new can but we need to eliminate that for sure before moving on to other possibilities.

Not long now, Robbo.

[robbo]

Thanks for your replies guys. Yesterday was my first proper ride since buying the bike from a Yamaha dealership, it was delivered by van, so other than a 6 mile round trip to the pipe benders with the stock exhaust on the bike, to be measured up for a link pipe, that was my total experience of it. I'd overhauled the exup valve as soon as it was delivered, finding no problems at all. I refitted the stock exhaust this morning and noticed an improvement but not what I'd consider acceptable. The previous, and first owner, had only averaged around 500 miles annually over the last 5 years and the dealership have suggested that running several tankfuls of fresh petrol through it could be the answer. So basically their advice is to get out and use it and re-evaluate the situation when I've put some miles on it. It is covered by a warranty, and am aware of the pitfalls of stale fuel. The throttle response is spot on when started from cold and the choke is on.

[Falcon 269]

Ah, now we get to it.  

Five hundred miles per year is a sure-fire way to clog up the pilot jets and possibly other passageways inside the carbs, Robbo.  I'll sort 'em when I have the carbs apart for 'Ivanising'.

Mike

[robbo]

Hi Mike,
That's great news. I had e-mailed you, before I read this reply, just to give as much info as possible. I can relax now as imagined it being a drama. Thanks for your reply.