Throttle body balance - zero=zero etc...

[MattW]

Firstly, I know the zero-zero procedure is a last ditch thing and has a lot of (justified) bad press, but...

Try as I might, I cannot get good throttle body balance on my 1100 ('94' single piece throttle cable). I've tried u-tube manometers, gauges etc but I can't get decent idle balance (all cables slack' butterflies on their stops) - the manometer says its right but it's not smooth and the brass air screws are a turn (or possibly a bit more) different. The throttle bodies are clean and blockage free (refurbished and rebushed by Scriminger a few thousand miles ago).

I've a feeling that a previous owner has fecked about with the throttle stops and I'd like to at least rule this out and reset them.

The only way I know of to do this, is the zero-zero thing (short of a carburettor flow bench, with I don't have in me garage ).

Has anyone had any success with this procedure, or can offer any pearls of wisdom?

Cheers
M

 

[Timolgra]

If the guages are reading a balance have you considered it may be something else. valves etc.?

 

[cookie]

I've a feeling that a previous owner has fecked about with the throttle stops and I'd like to at least rule this out and reset them.

the adjusters should be marked with paint blobs at the factory. these will still be intact if unmolested.

i have done the zero-zero thing in the past, and it is fairly straightforward. i'm not convinced that it is the cause of your idle issue though.

 

[duckspeed]

Have you made sure that the engine is basically sound, valve clearances etc.
Once a basic throttle butterfly setting is reached, the idle should be adjusted with the brass air screws.

 

[MattW]

Thanks all

I've just checked the valve clearances - all fine (perhaps a touch tight on the exhaust valves on one side but not anything to worry about - now corrected).

I've been out and bought a compression tester and both cylinders are within a gnats of each other cold.

The throttle stop screws do have paint blobs on them, but they are very clean and new looking - I've a feeling that Steve Scriminger marks the screws before dismantling the throttle bodies for refurb - if they were wrong when he got the TB's it doesn't really tell me anything.

 

[Flipfly]

I'm inclined to think it's something else. Surely a level balance is a level vacuum both sides and therefore pulling the same requirement both sides.
Could it be a lazy injector? Knackered ht lead/plug?
What about an air leak at the manifold?

 

[MattW]

I'm inclined to think it's something else. Surely a level balance is a level vacuum both sides and therefore pulling the same requirement both sides.
Could it be a lazy injector? Knackered ht lead/plug?
What about an air leak at the manifold?

Dunno.

I've just done the brake cleaner test for air leaks - all fine.

Plugs appear fine - they're not new but less than a couple of thousand miles old.

I've just had another crack at the TB balance - its sitting there at idle with the u-tube saying even vacuum but sounding rough and uneven.

I'm stumped to be honest. This isn't a new problem - it's never had great smoothness at tickover and balance off tickover has been the usual mare that you get with the single piece, daisy chain throttle cable (balance varies as revs increase - I just set it to be good at cruising rpm and live with a slight buzz either side).

The miss-set throttle stop thing was just a thought - I'm running out of ideas

 

[DrFarkoff]

What about the TPS have you checked what it is sitting at?

If the ECU thinks it's open throttle it overinjects fuel which can;t be burned because the butterflies are in idle position

If they get knocked they will be offscale

Yosarians 1150GSA last year around 650mv wouldn't tick over cleanly, sooted the plugs if doing lots of low speed stuff and burnt fuel @around 30mpg set the same bike back to 0.370 it goes back up to 45-50 mpg with a drop in oomph

That was

Dunno.

I've just done the brake cleaner test for air leaks - all fine.

Plugs appear fine - they're not new but less than a couple of thousand miles old.

I've just had another crack at the TB balance - its sitting there at idle with the u-tube saying even vacuum but sounding rough and uneven.

I'm stumped to be honest. This isn't a new problem - it's never had great smoothness at tickover and balance off tickover has been the usual mare that you get with the single piece, daisy chain throttle cable (balance varies as revs increase - I just set it to be good at cruising rpm and live with a slight buzz either side).

The miss-set throttle stop thing was just a thought - I'm running out of ideas

 

[(RIP) Bin Ridin]

CO2 Potentiometer adjustment?

 

[DrFarkoff]

CO2 Potentiometer adjustment?

Good call Bin I didn;t realise it was an 1100

MattW if you can get the use of a CO meter you want it sitting around 1.75 to 2.25% as per instruction from my foreman when at the dealership

Get it at working temp get it on the machine

DON'T just screw it loads!

See where you are mixture wise and see whether you need to weaken or enrichen the mixture

Then just do a 1/2 turn (need someone to confirm out to weaken in to enrichen, then gently raise the revs to clear the exhaust out and let the meter settle again

Good luck with that but do the TPS first it's less time consuming

 

[cookie]

Dunno.

I've just had another crack at the TB balance - its sitting there at idle with the u-tube saying even vacuum but sounding rough and uneven.

what about if you adjust a little outside of what's bang on, on the gauges?

sometimes you can get the best balance by doing the final adjustment by ear.

 

[MattW]

CO2 Potentiometer adjustment?

Good call Bin I didn;t realise it was an 1100

MattW if you can get the use of a CO meter you want it sitting around 1.75 to 2.25% as per instruction from my foreman when at the dealership

Get it at working temp get it on the machine

DON'T just screw it loads!

See where you are mixture wise and see whether you need to weaken or enrichen the mixture

Then just do a 1/2 turn (need someone to confirm out to weaken in to enrichen, then gently raise the revs to clear the exhaust out and let the meter settle again

Good luck with that but do the TPS first it's less time consuming

Thanks Dr F and Bin - I'll check the tps voltage.

The CO pot is something I hadn't thought of - I'll need to find a local place which will do it for me - not a device I possess

what about if you adjust a little outside of what's bang on, on the gauges?

sometimes you can get the best balance by doing the final adjustment by ear.

Thanks Cookie - I'll try this when I've ruled out the TPS and CO pot.

 

[DrFarkoff]

sometimes you can get the best balance by doing the final adjustment by ear.

Jaysus Yer talented


I prefer to use a screwdriver or two and a spanner or so

 

[nick.ct]

Without teaching grandmothers to suck eggs etc...................... but you have checked that the one piece throttle cable is moving freely and not sticking anywhere along its length?

Havent you?

DAMHIK

 

[MattW]

Without teaching grandmothers to suck eggs etc...................... but you have checked that the one piece throttle cable is moving freely and not sticking anywhere along its length?

Havent you?

DAMHIK

Good call but yes- it's fine - only a couple of thousand miles old (and I've been making sure that the throttles are on their stops at idle).

 

[motobiker]

Firstly, I know the zero-zero procedure is a last ditch thing and has a lot of (justified) bad press, but...

Try as I might, I cannot get good throttle body balance on my 1100 ('94' single piece throttle cable). I've tried u-tube manometers, gauges etc but I can't get decent idle balance (all cables slack' butterflies on their stops) - the manometer says its right but it's not smooth and the brass air screws are a turn (or possibly a bit more) different. The throttle bodies are clean and blockage free (refurbished and rebushed by Scriminger a few thousand miles ago).

I've a feeling that a previous owner has fecked about with the throttle stops and I'd like to at least rule this out and reset them.

The only way I know of to do this, is the zero-zero thing (short of a carburettor flow bench, with I don't have in me garage ).

Has anyone had any success with this procedure, or can offer any pearls of wisdom?

Cheers
M

bloody hell!

You've had this bike HOW LONG? and it still isn't running correctly so that you're blaming previous owners??

are you serious?

Give it up - take it to someone who knows what they're doing. and get it sorted once and for all. An hours labour.

I am amazed - you'll spend money on VERNS.... hard parts and Suspension and whatever else. but not on getting it running correctly.

WHAT>

Its like refurbing a house - new double glazing. new doors. new kitchen and bathroom. gardens landscaped and a block paved drive - when all the while you've got a massive hole in the roof.

the Lentini method is the equivalent of putting down a bucket to catch the drips. it masks the problem - but the problem will always be there.

 

[MattW]

bloody hell!

You've had this bike HOW LONG? and it still isn't running correctly so that you're blaming previous owners??

are you serious?

Give it up - take it to someone who knows what they're doing. and get it sorted once and for all. An hours labour.

I am amazed - you'll spend money on VERNS.... hard parts and Suspension and whatever else. but not on getting it running correctly.

WHAT>

Well, I've got my own little stalker - do you keep a little list of my posts and what I've bought / done to my bike?!

I've done tens of tousands of miles on this bike - I will judge when my bike is running correctly and I will decide if and when I want t take it to someone else. And I will most certainly decide what the hell I spend my money on you pompous arse.

 

[MattW]

Checked the tps voltage this morning. Possibly a bit high at .389 (although I know some bikes run better a bit higher) - reset it to .370

Subjectively the idle felt a little smoother but no time to go for a ride and try it out properly. I'll try to get the CO checked next week and take it from there.

Thanks (almost) everyone for the advice.

M

 

[Steptoe]

Check the resistance across the injector electrical connections. They should be around 16 whatitscalled, might even be 0.16, i just turn my electric meter to the bit i know measures whatsitsnames

If there's a difference betwen the two there's your problem.


[URL="http://www.ukgser.com/forums/showthread.php?t=77539&highlight=german"]HERE'S[/URL] one i did earlier in 2006 (never did get a beer ).... at the time i'd only seen the problem a couple of times. But over the last couple of years it's becoming fairly common as the bikes age and the mileage clocks up. .

 

[Trullion]

Just a thought, but are you sure that there is some play in the "choke" cable? I only ask because I recently spent a lot of time trying to work out why my '96 1100RS (single cable - new) didn't tick over properly only to find that a piece of grit had lodged in the pulley preventing the "choke" shutting properly. Dunno why it affected tickover balance, but it did. Just saying.