Sorting out the fuelling.

[the_lone_wolf]

So I suspect my new exhaust is making the bike run lean, hunts at low revs when cold and stalls easily, lacks the midrange it had and the top end has been boosted nicely. I just phoned Steve Jordan m/c with the intention of getting it up there and on their dyno as they can map the stock ECU, unfortunately the downside is that the first day they can book it in on a Saturday is the 8th Sept!

Q1 - Is running the bike a touch lean going to harm the engine, it was fitted a couple of weeks ago so it'll have been on the bike for 6 weeks before it gets sorted

Q2 - If the answer to A is "yes" who else will sort it out somewhere within a few hours of Southampton/Portsmouth - or is there something i can do in the meantime?

[the_lone_wolf]

so nobody knows anything? and i thought this was the most knowledgeable place known on the internets for SVs...

perhaps i should ask on a honda forum?

idk how much lean it will make it but if you run an engine to lean you'll get better fuel mileage and more power but it will destroy your engine from all the extra heat. that why when we lean an airplane at altitudes we go until it starts to loose rpm and then push it back in about 4 turns so we don't cause problems

In short.

It is possible that your new exhaust IS making the engine run lean. Changing the main jets could rectify this situation. Running lean is a hotter running engine which will lead to increased wear in the engine and possible damage. Running rich means your wasting petrol but could get good flames out of the exhaust on the over run.

[northwind]

Is it a full system or end can? You need to be pretty lean to have a high risk of causing damage, if you've got the standard filter etc in it then I'd be surprised if you're that bad. Jordans have both the kit and the knowhow to do a proper job of it, they're not the only place but they're one of the best places for this sort of work on an SV...

Originally Posted by BigApe

Changing the main jets could rectify this situation.

You know, if I was a small-minded pedant I'd point out that it's a pointy SV. But obviously, I'm not

Yeah well there you are. See what happens when you don't read all of the information available.

[northwind]

Coming form the inventor of BASAT as well

[the_lone_wolf]

Originally Posted by northwind

Is it a full system or end can? You need to be pretty lean to have a high risk of causing damage, if you've got the standard filter etc in it then I'd be surprised if you're that bad. Jordans have both the kit and the knowhow to do a proper job of it, they're not the only place but they're one of the best places for this sort of work on an SV...

it's just a slip-on can, but it's got nothing but open pipe between the cut in the exhaust tubing and the end of the system. it has the standard filter in. while you're here i should ask is it worth getting a decent air filter at the same time as getting the ECU remapped? if i get it remapped with the baffle out it's not going to bugger it up again if i put the baffle in for some journeys (i'm not anti-social 24/7)

when people say the engine is running hotter, would this not show up as an increase in coolant temp as well? the gauge hasn't shown any increase to speak of, and the exhaust downpipes aren't massively blue, just more of a tinge

cheers to all who replied

[northwind]

I don't know enough of what works with induction on the pointy SV to comment on that really... Though in general, if you're going to get it remapped anyway it makes sense to get as much benefit as possible.

Most people fitting race cans alone don't report too much in the way of problems- but then again, it's pretty difficult to accurately interpret the symptoms, as I learned myself- I was convinced I had no impact on the mids and a big kick up top, in fact I had a drop in the mids and a very small boost up top, but because it ran fairly well throughout the weak mid just made the top end feel strong.

If it's a straight through pipe from the standard set-up, chances are (like mine was) it'll be running rich. (If you're getting lots of pops/bangs/flames when letting off the throttle between 5k-3k then it certainly is)

If you want that extra 0.5bhp then feel free to put in a race filter before you get the ECU mapped, but depending on which set-up you get, will depend on if it'll make any difference or not;
If you're paying £300+ for a full set-up with a power-commander, then it'll make a difference.
If you're doing what I did and paid the £60 for a Yoshi set-up on the stock ECU (which only allows +/-5% alteration on the fuelling) then adding a race filter won't make much difference.

As for running the engine for that length of time... depends what sort of mileage you do. If you only do the odd bimble here and there, it's not going to make much difference. If you commute 200 miles a day on it, I'd keep it at home until you can get it mapped!

Hope that helps!

Ps. My idle speed also dropped after fitting the system, causing a few stalls - just alter the idle-speed screw on the left of the bike (Let me know if you can't find it, not obviously until you've used it) and set it back up 1.4k rpm.