Running issue after laying down ST1100!

[GTW]

Hi All,

I am new to this great forum and have had Pans for a while as well as other Hondas.

This first post is a tad frustrating!
For the first time I accidentally laid my Pan down getting it out of the workshop.

But to make matters worse it now won’t run on all cylinders through out the lower revs. It starts, it rides and the plugs are all good. It was not running when I laid it down, it was not dropped with a thud. I initially thought it might be the lean sensor but it would not start I don’t think if this was the case.
Before this it ran perfectly. It’s a 98’ abs/cbs/tcs model. My only other ‘long shot’ idea is that while leant down it caused something to stick in a carb..

I would be hugely grateful for any ideas.

Thank you
GTW

 

[ST1100Y]

My only other ‘long shot’ idea is that while leant down it caused something to stick in a carb...

A "carb shock" is plausible when a motorcycle got dropped...
A float shifted/got stuck, a float-valve shifted position, debris in the bowl got knocked loose and is now clogging a jet...
But it could also be electrical, like a HT wire got knocked loose at a coil, etc...

 

[Larry Fine]

If a lean sensor is triggered, it resets when the bike is upright and then you turn the key off and back on.

If it runs at all, the lean sensor is not the problem.

 

[GTW]

Thank you for your quick responses ST1100Y and Larry. I will check HT leads tomorrow, and in the back of my head I have thought about a carbs off situation but having just finished the carbs on my other one I hope this will be a last resort!
Hopefully it will all become clear tomorrow.

 

[Al st1100]

I

Thank you for your quick responses ST1100Y and Larry. I will check HT leads tomorrow, and in the back of my head I have thought about a carbs off situation but having just finished the carbs on my other one I hope this will be a last resort!
Hopefully it will all become clear tomorrow.

So how long did you have it running? When it tipped over it became flooded. Start it and increase the rpm's for a while there could be quite a bit of gas in there.

 

[GTW]

I

So how long did you have it running? When it tipped over it became flooded. Start it and increase the rpm's for a while there could be quite a bit of gas in there.

Hi I rode it for about 6 miles and filled it up. It’s almost as if lower revs not happy but happier getting on the gas at higher revs.

 

[Larry Fine]

It’s almost as if lower revs not happy but happier getting on the gas at higher revs.

That suggests clogged pilot jets.

 

[Al st1100]

That suggests clogged pilot jets.

it is possible sediment in the bottom of the bowls got disturbed and sucked up.

 

[jfheath]

Some random snippets of advice that I got on separate occasions about poor running which seemed to work for me.

1. Clean the fuel filter. Easy to get at on the 1100, by your right knee.
2. Add a fuel cleaner additive for one tank designed to dissolve 'stuff' -
3. Take the bike for a long run and use lower gears to keep the revs up at 5000 rpm. 30-40 mins made a very noticeable difference in mine.

But I have also had rough running which was eventually cured by replacing plug caps and leads.

I dropped my 1100 twice when stationary. It didn't behave any differently when I got it upright.
And I have had poor running without dropping the bike.
So The two may not be related - but ....

Water sinks to the bottom of a tank of fuel. Perhaps you have some water in there which is normally below the fuel intake pipe, which has now got into the fuel pipes and is finding its way through the system. Am I right in thinking that fuel with higher ethanol content (eg E10) helps with this, as it absorbs moisture ?

 

[GTW]

Some random snippets of advice that I got on separate occasions about poor running which seemed to work for me.

1. Clean the fuel filter. Easy to get at on the 1100, by your right knee.
2. Add a fuel cleaner additive for one tank designed to dissolve 'stuff' -
3. Take the bike for a long run and use lower gears to keep the revs up at 5000 rpm. 30-40 mins made a very noticeable difference in mine.

But I have also had rough running which was eventually cured by replacing plug caps and leads.

I dropped my 1100 twice when stationary. It didn't behave any differently when I got it upright.
And I have had poor running without dropping the bike.
So The two may not be related - but ....

Water sinks to the bottom of a tank of fuel. Perhaps you have some water in there which is normally below the fuel intake pipe, which has now got into the fuel pipes and is finding its way through the system. Am I right in thinking that fuel with higher ethanol content (eg E10) helps with this, as it absorbs moisture ?

John thank you for your advice, I will check those things. The reason I am a little baffled about this is that two months ago it had a thorough service by myself, including new plugs etc, carbs stripped and cleaned and set up professionally, it’s a 30k miles Pan and really did run as new…..before I stupidly laid it down! I will use everyones advice and a couple of long shots I have and if no joy I think it’s a carb off job and clean/inspect everything accessible from removing the float bowls, I don’t want to lose settings.
Thank you again for your advice and I update, hopefully positively!

 

[jrp]

When was the last time you replaced the fuel filter?

 

[GTW]

I replaced the fuel filter 2 months ago after the carbs were stripped and cleaned with the service. I am hoping I will have time tomorrow to start to solve the problem!

 

[bdalameda]

Have you checked the choke(enrichener) cable? I was thinking that this cable may have gotten pulled when your bike dropped or was uprighted. The cable housing end might have slipped in the clamp holding it near the carbs and the choke may be held open a bit causing the low speed issues. The enrichening circuit does not have much effect at higher throttle openings but it has a lot at idle or off idle. Just a thought.

 

[GTW]

Have you checked the choke(enrichener) cable? I was thinking that this cable may have gotten pulled when your bike dropped or was uprighted. The cable housing end might have slipped in the clamp holding it near the carbs and the choke may be held open a bit causing the low speed issues. The enrichening circuit does not have much effect at higher throttle openings but it has a lot at idle or off idle. Just a thought.

Another great thought thank you, much appreciated, will check that too.

 

[Uncle Phil]

Any chance the TCS module got whacked in the drop?
They can cause ignition issues if faulty.

 

[GTW]

Any chance the TCS module got whacked in the drop?
They can cause ignition issues if faulty.

I did think about that briefly, I know very little about that, so you know how to test it or eliminate it to diagnose?

 

[jfheath]

If you set off riding and after a few metres the ABS light goes out, then both of the sensors are working OK.

You can turn off TCS on one of the buttons by your left knee. It is (or was on mine) a momentary contact 'switch' which instructs the ECM to activate/deactivate it. But on mine, it did not remember the settings, so you have to turn it off each time. The warning lights indicate the status.

If the system decides that the sensors aren't giving consistent information, then the ABS lights will not go out and neither ABS or TCS will work and the warning lights come on.

If traction control is on but the sensors have an intermittent fault - so it doesn't detect it at startup - it will not let you accelerate when it is failing, but you can plod along at walking pace. As soon as it reconnects it will lurch forward. The issue is that at anything above a few mph, any difference between front and rear wheel speeds - as detected by the sensors - is regarded as wheel spin by the TCS and it cuts engine power. Quite dramatically. My sensors started to fail over a couple of weeks. The first serious failure was when accelerating hard to overtake at 70mph. The rear sensor failed, and it decided to reduce powert to the engine to regain traction. Normally that would be a momentary blip to reagain traction, but in my case with a failed sesnor, the cut out nearly had me through the windscreen. After that it wouldn't work at all and I had to remember to turn it off every time I set off riding.

There are earlier versions of TCS that I do not know about - mine was on a UK 2000 ST1100AY which had ABS/TCS/CBS - I think that these models started with the ST1100AT (1996).

 

[GTW]

If you set off riding and after a few metres the ABS light goes out, then both of the sensors are working OK.

You can turn off TCS on one of the buttons by your left knee. It is (or was on mine) a momentary contact 'switch' which instructs the ECM to activate/deactivate it. But on mine, it did not remember the settings, so you have to turn it off each time. The warning lights indicate the status.

If the system decides that the sensors aren't giving consistent information, then the ABS lights will not go out and neither ABS or TCS will work and the warning lights come on.

If traction control is on but the sensors have an intermittent fault - so it doesn't detect it at startup - it will not let you accelerate when it is failing, but you can plod along at walking pace. As soon as it reconnects it will lurch forward. The issue is that at anything above a few mph, any difference between front and rear wheel speeds - as detected by the sensors - is regarded as wheel spin by the TCS and it cuts engine power. Quite dramatically. My sensors started to fail over a couple of weeks. The first serious failure was when accelerating hard to overtake at 70mph. The rear sensor failed, and it decided to reduce powert to the engine to regain traction. Normally that would be a momentary blip to reagain traction, but in my case with a failed sesnor, the cut out nearly had me through the windscreen. After that it wouldn't work at all and I had to remember to turn it off every time I set off riding.

There are earlier versions of TCS that I do not know about - mine was on a UK 2000 ST1100AY which had ABS/TCS/CBS - I think that these models started with the ST1100AT (1996).

Thank you John I’ll look at that, I do think from the ride after from after the drop that the ABS light went out but will check

 

[GTW]

Hi All,

Firstly thank you for all your help and suggestions, hugely appreciated.

Calm is restored to the workshop.

I did all the mechanical checks you guys suggested. I checked the TCS sensor by turning off.

Late last night I opened the air box and sprayed STP carb cleaner down the rubber air snorkels and into the carb circuit holes at the base of the plenum for each card, and let it cook over night.

Started it this morning and still unhapppy. So more carb spray and then as John suggested, I added Liquid Moly carb and valve cleaner additive at quite very a generous concentration, then went for a 4500rpm hard ride for an hour and all is well, runs evenly and start on the button again. Must have been some crud in the carbs when I laid it down.

Boy am I pleased I did not have to take the carbs off. Thank you.

I do have a query about fuel filters, do you use pattern or genuine and does this make a difference. I live literally down the road to David Silvers and t everything from them and I always go pattern but given this latest experience on carbs that were recently cleaned and a new fuel filter I am wondering if the fuel filters are no good. Any thoughts, or maybe you use completely different fuel filters.

Can I have one more question. With out starting a controversial debate, I know this has been covered many times, but using Bridgestone T32 on 1100’s does the going up one size of width for rear make a negative difference as it did on my 96 VFR. Also do you guys run GT spec T32 on both front and back or just the back? Have you tried T33’s.

I think I’ve probably used my quota of questions already as a newbie to the forum!

Thank you again
Ged

 

[DeanR]

I recently replaced a used up T32 with a 170/60 BT020 due to a stupid cheap price that I could not pass up. Have always previously used the proper 160/70 rear . Seems to be just fine other than a bit harder to het o the center stand.

Glad your bike is back to normal running.