Who's good for dyno work these days.

Preferably someone who's on a reasonable route between the northwest of Scotland and the south of England.

I need/want to get the GS set up properly, standard carbs and airbox but into a stainless Y piece*, bespoke** link pipe and a TT600 race can.

I'm not looking for maximum power, just so its starts and runs as well as it will as part of its being tarted up for sale.


* I can't remember the make, but it's an offset Y rather than a bent T.

** Whatever I had lying about the place that could be made to fit.

Hilltop, he'll sort you out, knows a bit about bikes

JohnnyBoxer said:

Hilltop, he'll sort you out, knows a bit about bikes

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Not about airheads he doesn't. I had a few runs done there but it was expensive and not that helpful.

spr racing at ruddington (just outside nottingham) are in a different league to hilltop with the service they offer. It cost me £50 to have my guzzi sorted out and was worth every penny. http://www.sprracing.co.uk/dyno they have a proper workshop and not a shithole like hilltops place.

The problem you have with the bings is a shortage of jet sizes to fine tune.

Another option is the guys at silverstone. Richie Moore uses them so they're used to airheads.

Thanks, I shall make enquiries.

I phoned around and got some 'Yes we can' type answers. The only problem is I have to supply the jets. It probably needs pilot jets too and I'm too mean to lump out the best part of a ton on pretty bits of brass I'll never use nor be able to sell.

Looks like it'll just get the carbs balanced then.

So well expect yet another evil running bag of shit up for sale at top dollar then?

We are lucky here that out local bike carb specialist is both a Mikuni agent and also our top bike dynatune guy - if you think bing parts are expensive you should try try tuning a Mikuni from scratch - probably cheaper to buy a new carb already set up.

Before rear wheel dynos were around folks still managed to tune bikes, usually by test runs up a decent sort of hill where the motor was pulling hard.

As Rob has said not a lot of bits around for Bings , but new stock needles and needle jets are a start, and a main jet one size either side of what you have now.
New diaphragms and both strengths of slide springs are good to have too, and properly set float levels are essential.
Then a play around with the main jets , slide springs and needle position should get you somewhere.
Not perfect but close enough.
With aftermarket exhausts folks seem to get widely different results.
Some seem to need major alterations to the airbox - most top tuners sell one which is probably a lot a lot less restrictive, but everything from clamshell airboxes , two large size intake trumpets, removing both trumpets, perforating the top of the box and extending the length of the bell mouths inside the box have been suggested.
I like the carbs set a little further from the head too, Amal Mk 11 molded intake rubbers do this and they let you blend the intake to both the carbs and the head without a step either end.
Some Y pieces are notorisly difficult to tune to, the Keihin in particular needs a fair bit of experimention and a much freer flowing and probably larger volume exhaust if it is to work properly.
No point in going too small with the end muffler if noise bothers you - a small muffler simply has to be too restrictive if noise reduction is important and will cost you power.
I had a small Gletter can on my GS and it did just that unless it was unsocialby loud, although it was possible to baffle it down till both power and noise were acceptable - I dont make a lot of full throttle, full power runs in my normal day to day running!

Rob Farmer said:

Not about airheads he doesn't. I had a few runs done there but it was expensive and not that helpful.

spr racing at ruddington (just outside nottingham) are in a different league to hilltop with the service they offer. It cost me £50 to have my guzzi sorted out and was worth every penny. http://www.sprracing.co.uk/dyno they have a proper workshop and not a shithole like hilltops place.

The problem you have with the bings is a shortage of jet sizes to fine tune.

Another option is the guys at silverstone. Richie Moore uses them so they're used to airheads.

Click to expand...

Rob, I've got an Innovate for setting the carburation, just needs a threaded boss welding into the exhaust pipe.
https://conceptzperformance.com/sal...ital-air-fuel-ratio-meter-inn3723_p_25475.php
They are available in the UK as well.
It has saved me a fortune over the years, especially when setting the 32mm Bing up for my K100.
It's benefit is that you're getting readings as you're using the bike on the road rather than the dyno.
Worth considering if you're regularly fine-tuning your carbs.

I have two innovates and am a big fan of them but getting the top end jetting right is too damn scary on the road. Much safer on a rolling road.