Farting and coughing

A little while back I bought an '03 Sportster (carb model) from a guy who
warned it 'runs perfectly fine but can chuff out' at roundabouts. He was not
lying: it did and still does - when/if you blip the throttle to drop a gear
for the roundabout. (Easy got round though - just don't blip and, strangely,
it doesn't very often/hardly ever do it anywhere else unless it's cold!)

Recently, the bike went of to a 'Harley specialist' to have this 'coughing'
sorted out, a 2,500 service and an 883 to 1200 rebore. (*Big mistake* - I
got to meet the biggest wanker in the business!!

It came back (eventually - gone three weeks in the best riding weather of
the year) and was much the same: still chuffing out at roundabouts and now
farting and popping on the overrun when slowing in high gears. Then it
started pissing oil from the rocker box gasket....

http://www.moirac.adsl24.co.uk/showntell/OilLeakA.JPG

http://www.moirac.adsl24.co.uk/showntell/OilLeakB.JPG

So, (the poor man pays twice, don't he?) without further ado, the bike went
off to a main HD dealer who tidied up the oil leak, checked over the rebore
work and changed the jets in the carb.

Its back, goes like a *thrusting thing* but still chuffs out at roundabouts
and still pops and farts on the overrun - but maybe not so much and not
enough to bother me. But what's this chuffing out biz - I asked the local
bike shop that if, presuming the main HD people knew their stuff and the
jetting was now right, did it need it need the needle shifting or summat?

Fucked if I know....

TIA for any ideas/observation!

 

It's a Harley, that's "character".

 

In message <haifi7$1cl5$>, Keith G
<big snip>

Need more details...

What 1200 conversion was it? Bore & dished top pistons, bore and flat
top & relieve head, bore & flat top & 1200 heads, bore and flat top & SE
heads?
What carb jetting? Is it dynojetted?
What airbox? Stock, drilled, cut backplate, Mikuni backplate, K&N?
What pipes? Stock, drilled, SE, V&H, etc?
What ignition module?
What if anything has been done to the VOES?
Are you sure the inlet manifold has been sealed to the heads?

Much as I hate to admit it around here, I've got previous.

 

Wiseco pistons, no head work whatsoever, see:

http://www.moirac.adsl24.co.uk/showntell/Conversion-02.jpg

(I asked for pix of the strip down.)

No idea, it was done in 'Newmarket' in the remedial work after the oil leak.
I only have the old jets in a bag....


Is it dynojetted?


No.

All stock - '03 model:

http://www.moirac.adsl24.co.uk/showntell/DSC_9173.JPG

Stock, as pic.

No idea - ?

Nothing AFAIK....

**** Nose.

(I posted in 'classic' hoping there was someone with carb experience on a
bike which is basically a 50 year old design!! ;-)

More popping/farting today but no 'chuff outs' - I just let the gears drop
on the revs/road speed with no blipping! I can live with a bit of
'character' as Austin calls it, but it would a pity to do so if a twist of a
screwdiver could/would sort it...??

Reminds me, the Newmarket HD van driver said there's a 'secret mixture
screw' on the carb if you drill out the blanking off plate?? All very
mysterious!!

 

That's not good.

That's not good.

My first suggestion would be to do a stage 1 conversion and see if that
sorts it. There's good reason that it's done on virtually all Harleys;
they're basically so well sealed up on the inlet and exhaust to get
through the emissions tests that the poor things can hardly breathe and
as a consequence they run like dogs.

Where are you? I've got a dynojeted carb on the shelf (in Cheltenham)
that'll bolt on and simply using that without the airbox and with an old
pair of pipes with the baffle drilled through/knocked out will see if
that sorts it.

Other than that it might be worth trying a replacement ignition module
(got one of those too).

 

It bloody kills me that modern bikes are so knackered with/by regulations
that you need a litre's worth before they can move their own weight - what's
the point if it all, if people just keep getting bigger and bigger motors?
Anyway, it was going to have a Stage 1 and the Screamin' Eagle slashcuts
I've got here put on, but before it went off for the rebore I put the
slashcuts on to check them out and decided I didn't need all the extra
noise - so the Stage 1 didn't happen!

Oh, right on your doorstep - Cambridgeshire (St Neots)!!


I've got a dynojeted carb on the shelf (in Cheltenham)

Hmmm2....

The bike's such a *newey* I'm loth to start hacking it about! (6 years old
on paper, only 2K miles when I got it!)

Sit tight 'til I've had a bit of a think - 'ow much do you want for the
carb?

Keith

(the email address is good)

 

I know what you mean, but as was once pointed out to me by the HD dealer
they tend to do the stage 1 on most bikes as part of the PDI, and most
of the rest at the 1st service when they realise they need it.

You're right about the exhausts; the route I went was to buy some new
standard pipes from ebay (about £30), then have a 5/8" hole drilled
through the baffle. Worked properly and wasn't overly loud.

Bottle of wine?

Thing is, if you bolt on the carb, leave the intake open, and pop on
your loud pipes, you can at least discover if this solves the problem.
If it does then you can spend the time to get the proper open back
plate, K&N, quiet but free flowing pipes, head breathers etc. If not
then you can look harder for the fault.

Swapping the carb and pipes should take you an hour at the most if you
know your way round your tool kit.

 

Not that easy to post and a bugger to email!!

I was hoping not to have to get into all this....

OK, but how would that differ from me taking off the air cleaner and fitting
the slashies for now and taking it it for a run? (Isn't dynojetting a
'dynamic' exercise that need to be adjusted and measured while it's being
done?)

What's mystifying me is that it's come back from the 'the best HD workshop
in Europe' (??) with different jetting but not running a whole lot better
than it did from 'Pikey Bikes'....??

IOW, who TF can you trust with these things at the end of the day....???

 

Details, details

Well you started it, you bought a Harley...

Very little; good plan. 20 minutes and a set of earplugs and you're on
your way.

Ah no, Dynojet provide a set of jets, needles etc to replace the stock
ones and tunes out the dip in the power curve to make it quiet. This
could be fine tuned on a dyno, but the Dynojet kit effectively gives you
an "average".

The reason I offered up the carb is that dynojet charge £90 for the kit
alone, but a pre-loved carb with kit fitted is worth 3/5 of bugger all.

To be fair, I suspect the core of the problem is that you're still on
the stock airbox and pipes and you'll never get it running nicely till
you step on from that. Yes I know that's how my Harley makes them, but
they only make them like that to get them through the noise regs in the
happy knowledge that the owners.

Your idea of taking off the ham can (not just take off the filter as the
restriction is getting air into the box, not the filter) and popping on
the loud pipes is a grand plan. Do it and see if that fixes the problem.

But not today as it's raining

 

Yes. Amazing really, considering the tsunami of Harrleee bullshit that
engulfs you when you do - which is a pity because as bikes they've got a lot
going for them and I love riding mine! (Talking about the Sportster,
here...)

(If you post on a Harley ng, it appears you've got to kick off with summat
like 'the drinks are on me'....FFS!!)

Hovered today and even took the 'ham can off' but couldn't bring myself to
do it - it's going down the exact same route that I did with a Hinckley
Bonneville fairly recently and, after fitting noisy Norman Hyde cans, jets
and air intake/'velocity stack', ended up with a noisy/farty bike that
disturbed *my* fekk'n peace everywhere I went!!

(Interesting little *squirter* when you operate the throttle - nothing
*subtle about it!!

Well, let me know what that equates to in munny and maybe it can live on my
shelf for a while. Perhaps it could do with a change of scenery?

....will knock them into shape?

It's the same for every bike these days.

No, it was a lovely, sunny (but fresh) autumn day with lots of golden leaves
blowing about, so I went for a nice ride round the lanes after replacing the
ham can (see above) - I'll have another scowl at it tomorrow!

I've definitely stalled atm....

 

OK, did that:

http://www.moirac.adsl24.co.uk/showntell/Exhausts.jpg


No good at all - coughed, popped and farted worse than ever and *louder*!!

I'll have the plugs out shortly and see what colour they are, but I think
I'll be throwing this little problem up 'Europe's finest' workshop's arse -
they jetted the carb...!!

The popping, I notice, is only on *slowing on the throttle*....

 

IME that often means an air leak somewhere in to the exhaust. Careful
attention to silencer clamps and even a smear of joint paste may be
required. Otherwise it sounds like way too lean idle jets.

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I've had a look at the plugs and there's nothing *rich* about the whole
setup from what I can see of it! I've either got to get used to the idea of
a bit of farting and popping or go deep into the carb and intake setup, I
reckon.

Thanks for the suggestions.

 

E-mail me your addy and I'll bung the carb in the post