1100 once piece throttle cable sync

[MattW]

This weekends job will be to have another go at balancing the TB's on my 1100 (which has the old style once piece cable).

I've done the idle balance before but never managed to get the high rpm balance right - there's a buzz at cruising rpm which I'd like to try to eliminate.

Helpfully, the Clymer manual completely ignores the one piece cable and the factory manual (poorly) describes a procedure which seems to be as follows:

1. Adjust choke cable play to ~1mm
2. Adjust twistgrip to left TB play to ~0.5mm
3. Adjust cable play between TB's to zero (although how you do that accurately, I've no idea)
4. Set idle sync as normal using the brass air screws

There's no mention of balancing at higher rpm (for either the one piece or junction box cables).

Is this the best you can do for the one piece cable or does anyone know of a better guide to adjusting this daft cable arrangement?

ta
Matt

 

[Wrigsby1]

The advice is about right even if it sound skewy. My way just a week or so ago...

1st make sure all 3 cables have a good free play. Choke,LH adjuster and RH adjuster. Then set brass idle adjusters for tickover balance.

2nd bring LH cable adjuster for top part of cable up to approx 0.5/1mm. This adjustment can vary slightly as it doesn't affect the crossover balance.

Then using the balance gauges, adjust the slack out of the RH adjuster to level the balance at something like 2.5 k revs (held on throttle). If the stop screw are something like factory set this should be at approx zero free play on the RH adjuster with the throttle shut.

It is worth having a ride and repeating the balance check as it is so easy to set up. As the top portion of the throttle cable has a cable nipple fitted into the LH TB wheel then the initial free play can vary variable. It is the balance between the sides via the crossover that is so important.

Obviously a check of the TPS mv is a good idea before hand and the main reason why the balance can be such a bstard is due to either no free play in the choke or too tight/no free play on the LH main cable keeing the LH butterfly open as you try to set.

Also Steptoes tip disregarding the 2.25 turns of the brass idle screws to set tickover is a good one. I can only set 950-1000rpm with the Idle screws at 1 turn out and this is fine. What with having the TB's off for a big clean and accurate rebalancing of the TB's i now have a bike I never knew I had It now idles and purry slow runs like a pussycat

 

[MattW]

The advice is about right even if it sound skewy. My way just a week or so ago...

1st make sure all 3 cables have a good free play. Choke,LH adjuster and RH adjuster. Then set brass idle adjusters for tickover balance.

2nd bring LH cable adjuster for top part of cable up to approx 0.5/1mm. This adjustment can vary slightly as it doesn't affect the crossover balance.

Then using the balance gauges, adjust the slack out of the RH adjuster to level the balance at something like 2.5 k revs (held on throttle). If the stop screw are something like factory set this should be at approx zero free play on the RH adjuster with the throttle shut.

It is worth having a ride and repeating the balance check as it is so easy to set up. As the top portion of the throttle cable has a cable nipple fitted into the LH TB wheel then the initial free play can vary variable. It is the balance between the sides via the crossover that is so important.

Obviously a check of the TPS mv is a good idea before hand and the main reason why the balance can be such a bstard is due to either no free play in the choke or too tight/no free play on the LH main cable keeing the LH butterfly open as you try to set.

Also Steptoes tip disregarding the 2.25 turns of the brass idle screws to set tickover is a good one. I can only set 950-1000rpm with the Idle screws at 1 turn out and this is fine. What with having the TB's off for a big clean and accurate rebalancing of the TB's i now have a bike I never knew I had It now idles and purry slow runs like a pussycat

Thanks - that makes sense

I'll give it a go this weekend,

cheers

 

[uncle dick]

Wherever the idle air screws end up, make sure they're equal in terms of no. of turns out (give or take 1/4 turn). Set them both the same then, having set the tps, adjust the rh butterfly to balance at idle. You can then set the cross-over cable and have a much better chance of staying in balance as you rev up.

Dick

 

[Wrigsby1]

Wherever the idle air screws end up, make sure they're equal in terms of no. of turns out (give or take 1/4 turn). Set them both the same then, having set the tps, adjust the rh butterfly to balance at idle. You can then set the cross-over cable and have a much better chance of staying in balance as you rev up.

Dick

The only way that is put out slightly is that the butterflys are set to be slightly open even when fully "closed". Even adjusting the stops doesn't get rid of the gap so there is no "totally closed" setting. If the brass screws are a couple of turns different from each other then it may make a difference. If not then it won't as you can't be sure of the accuracy of their air flow either. I know by trying

If you take off a TB and look "through" it with the butterfly closed this gap will show up.

 

[MattW]

Wherever the idle air screws end up, make sure they're equal in terms of no. of turns out (give or take 1/4 turn). Set them both the same then, having set the tps, adjust the rh butterfly to balance at idle. You can then set the cross-over cable and have a much better chance of staying in balance as you rev up.

Dick

Thanks for the input uncle dick However, I've always been told (with which I must admit I agree) that setting idle on the cables rather than the airscrews is not the thing to do. As Wrigsby1 says, the butterfly stops are factory set on a flow bench and idle balance / tickover should be done using the airscrews only. I would have thought that balancing at idle on the cables would lead to potential issues with cable stretch and sticktion in cables / throttle etc

At idle, my brass screws are about 1/4 turn different (the right hand screw being slightly more closed) but as my right hand TB is ticking (refurb of both TB's due this winter) it wouldn't surprise me if it's admitting a bit of air via the butterfly shaft bushings. I can live with this difference until I get them refurbed.

So, I think I'll have a go at the method Wrigsby posted above. I'm not going to touch the TPS as apart from a slight buzz at motorway speeds it runs really well without a hint of surge etc - I don't want to tempt fate and fix what aint broke

 

[uncle dick]

I never said balance it with the cables. We all know about throttle shaft / bush wear (the famous tick) so sometimes the butterfly stop screws may need a tweak to compensate. Use the cables to set part throttle balance afterwards. Watch the balance gauge (whatever you're using) whilst gently opening and closing the throttle and you'll see the right hand pot lagging behind the other one due to the crossover cable (great design ). Adjust for the best compromise at open, cruise and closing throttle.

Worked for me

Dick

 

[MattW]

Aargh!!! - what a pain the feckin' arse that is.

Just spent hours faffing around trying to get it balanced and I still don't think it's right - every adjustment affects every other adjustment with this stupid arrangement. Even the twistgrip to Left TB slack affects the left to right crossover slack because of that stupid wrap round on the left hand TB where the nipple moves slightly in the quadrant When I got part throttle balance right, it affected the tickover balance, so I adjust the cable to bring the butterflies back onto the stops and it throws the part throttle balance out again. I ended up chasing bloody adjustments from side to side endlessley

On the plus side, I don't think I've made it any worse but that's about as good as it gets and I've still got a slightly lumpy hesitant idle even with the idle balance perfect - I've no idea what's causing that...

Apologies for the rant, I'm going to take my frustrations out on some logs with a big splitting maul.

 

[motobiker]

And people wonder why, whenever the question; 'which 1100?' comes up. I get on my soap-box and say. 97 (R reg) or later.

 

[Mac]

My 1100 is as smooth as mr & mrs smooth on national tick over day


It's a 94

 

[motobiker]

My 1100 is as smooth as mr & mrs smooth on national tick over day


It's a 94

So was my (from new) 96.... I didn't replace it with another 96 though. In fact it didn't cross my mind to. I wanted a 97 on and with just a bit of patience came up trumps with a 99.
A lot of the earlier bikes were just fine. my own included. However it was most definitely a lottery. I was buying the replacement as a 'keeper' and so a later bike made sense to me.

Just as.. if i were to go for an 1150. I would go for a pre 02 (Non-servo/non-twinspark.)

Or.. if I were to go a bit mad and get a 1200. it would be an 08 onwards.

 

[davegs]

Frottles

E bay comming up?

 

[Mac]

Moto....don't ever go mad, not ever

Everytime i spend a day on my 1100 i feel like i've won the lottery, how something this big and old can be so smooth, predictable and planted makes me appreciate how awsome they are, yeah it's16 yrs old but i'm not and time has taught me how to get the best out of bikes.

It used to be how quick i could get to the horizon, now i know better

Clear skies

 

[MattW]

E bay comming up?

Never Dave!

I love my 11 - the TB balance is just a niggle.

On the test ride after my balancing frustration, I instantly remembered why I like it so much.

I'm going to get the TB's refurbished by Scriminger this winter - I've a feeling that the lumpy idle may be due to air ingress via the spindle bushings.

 

[Wrigsby1]

Never Dave!

I love my 11 - the TB balance is just a niggle.

On the test ride after my balancing frustration, I instantly remembered why I like it so much.

I'm going to get the TB's refurbished by Scriminger this winter - I've a feeling that the lumpy idle may be due to air ingress via the spindle bushings.

Matt, don't let it drive you mad

If you find yourself opening the RH butterfly to balance then it will get to be a PIA. Start with keeping slack in the cables and balance via the brass screws. Then tension the RH adjuster to take out the slack. If you can balance the upper rev balance without going tight on the RH cable then do it and adjust the brass screws to suit on tickover.

May be a chance to give the TB's the "big clean". The tickover bypass gets really shitty and needs gently delving into with a pointy object to remove carbon. It also gives you a chance to clean the fck out of the cable wheels and check for play in the spindles. I thought i had play as i had the tappety RH TB but it was side to side play rather than any air leak.

Also check the rubber manifold to head seal for leaks as they are a compression fit. Usual checks of other rubber seals etc.

I thought for 10 years how crap the long cable was but with a bit of effort i have recently got it pretty spot on. In fact i can't quite believe it Even with an old cable...

They just have to do things in the right order...