Alas Another Uncle Phil ST1100 Mystery Thread

[Uncle Phil]

Well, Frost, one of my 97 ABSII ST1100s has decided once again to be ugly.
I've been hunting down a carb issue so I have her in my shop.
I was starting her to test to see if I had the issue resolved.
I got tired and called it quits for the evening.
When I go back out there the next morning, she will not turnover.
All I get when I hit the start button is a 'buzz' and the light bar above the speedo goes dim.
Already tried a known good battery and another known good starter but no joy.
It has already had the 'red wire' bypass done.
Battery terminals looked fine both on the starter end and the battery end.
It's almost as if the engine is locked up.
I am confused as to what could have instantly gone south overnight in a heated garage.
I guess I could pull all the plugs and see if she will turn over.
It seems I never have the 'simple' problems it is usually really weird stuff.
Any ideas?

 

[Bug Dr.]

Scrap it and buy an RT 1300
Mike

 

[jdmccright]

I'd pull the plugs and see if any are wet from fuel. If a float stuck open it could have flooded a cylinder or two. Also check the oil level and see if it's overfull.

 

[Uncle Phil]

Scrap it and buy an RT 1300
Mike

Why? So I can have very expensive problems as in B(reak) M(y) W(allet)?

 

[Uncle Phil]

I'd pull the plugs and see if any are wet from fuel. If a float stuck open it could have flooded a cylinder or two. Also check the oil level and see if it's overfull.

Plugs look fine, oil at proper level - BTDT.
I tend to think it is electrical because it was 'all of a sudden' but I could be wrong.

 

[Larry Fine]

Do some fall-of-potential testing while trying to start it, such as checking for voltage between the battery + and the starter + terminal, and between battery - and the engine case.

Any appreciable voltage drop will indicate a high resistance in the current pathway, which can be narrowed down by process of elimination with additional point-to-point testing.

 

[jdmccright]

Plugs look fine, oil at proper level - BTDT.
I tend to think it is electrical because it was 'all of a sudden' but I could be wrong.

Well, you did say you left it overnight, so that's enough time to fill a cylinder...of course if you had bypassed the fuel shut-off, info not shared but a possibility.

Otherwise, yes something sudden tends to be electrical. Could be a fault to ground. You might check for amp draw with key on and when trying to start. Maybe an ignition lock issue?

 

[Uncle Phil]

Well, you did say you left it overnight, so that's enough time to fill a cylinder...of course if you had bypassed the fuel shut-off, info not shared but a possibility.

Otherwise, yes something sudden tends to be electrical. Could be a fault to ground. You might check for amp draw with key on and when trying to start. Maybe an ignition lock issue?

Fuel cutoff gone a long time ago.
Next step is to replace the starter relay (since I have a few spares and it is pretty easy to do ) and see if that does anything.
After that would be to pull the plugs and see if she will turn over.
After that I guess I would check the switch.
So far all connections are corrosion free and clear.
I do appreciate the suggestions.

 

[motornut]

Where did you hide the voltmeter? plug it onto the battery and start at the beginning

 

[motornut]

Sounds like the battary went dead overnight

 

[Fred Primmer]

I had a car one time that had a bad section on the starter commutator. It would start fine unless the brushes stopped on the bad section at the end of a start cycle. The starter wouldn't work the next time you tried. The interim solution was to get under the car and lightly tap the starter with a hammer until the starter vibrated enough that brushes touched an adjacent section of the commutator. Back then, who had money for a new starter!

 

[Uncle Phil]

Where did you hide the voltmeter? plug it onto the battery and start at the beginning

Already BTDT ...

 

[Uncle Phil]

Sounds like the battary went dead overnight

See post 1 - already tried a different battery.

 

[Mike M.]

I've had a hydro-lock due to stuck float but clearly that's not the case here as you said the plugs look fine.

I'll be watching to see what you find.

 

[Uncle Phil]

I've had a hydro-lock due to stuck float but clearly that's not the case here as you said the plugs look fine.

I'll be watching to see what you find.

How did you resolve it?

 

[Mike M.]

I've had hydo-locks on both my 1997 st1100 and my GL1100. If you pull the plugs and the motor spins that is the issue. Before hitting the starter button either move the bike outside or put rags over the plug holes as if a cylinder is full gas , it will spray the garage and possible yourself. I know this for a fact : )

On the ST1100 I put the plugs back in and it was a one time thing. (But shortly after I had to rebuild the carbs anyway as the o-rings on the crossover tubes failed and fuel was leaking from the overflow onto the floor, but not into the motor)

If you think it might happen again you will want to put the vacuum petcock back on to stop it from happening again. In my case it must have been a piece of dirt or the float just hung but I did put new float needles in when I rebuilt the carbs.

The 1983 Goldwing was the last year with a manual petcock so I just turn it to off.

 

[Bikeric]

Bad earth or ground your side of the pond Uncle Phil?

 

[Uncle Phil]

Bad earth or ground your side of the pond Uncle Phil?

Those seem to be fine.

 

[Uncle Phil]

I've had hydo-locks on both my 1997 st1100 and my GL1100. If you pull the plugs and the motor spins that is the issue. Before hitting the starter button either move the bike outside or put rags over the plug holes as if a cylinder is full gas , it will spray the garage and possible yourself. I know this for a fact : )

On the ST1100 I put the plugs back in and it was a one time thing. (But shortly after I had to rebuild the carbs anyway as the o-rings on the crossover tubes failed and fuel was leaking from the overflow onto the floor, but not into the motor)

If you think it might happen again you will want to put the vacuum petcock back on to stop it from happening again. In my case it must have been a piece of dirt or the float just hung but I did put new float needles in when I rebuilt the carbs.

The 1983 Goldwing was the last year with a manual petcock so I just turn it to off.

I pulled the two front plugs and tried to spin it but no change.
I'll have to pull all of them and see what happens if a different starter relay doesn't help.

 

[bdalameda]

I had a car one time that had a bad section on the starter commutator. It would start fine unless the brushes stopped on the bad section at the end of a start cycle. The starter wouldn't work the next time you tried. The interim solution was to get under the car and lightly tap the starter with a hammer until the starter vibrated enough that brushes touched an adjacent section of the commutator. Back then, who had money for a new starter!

Sounds like a common VW problem from back in the 70's.