1150 GSA Ran Rough, Died, Wont start...help!

[Robster]

On my way up to the NEC Show on Saturday I had a problem with my 03 1150 GSA ('03, ABS, 57k) – cruising along at 70mph on the M40, I'd done about 60 miles from home when there was a sudden loss of power and the bike slowed.

I throttled on a bit and it made a terrible racket, sounding and feeling like it was running on one cylinder.

I pulled straight over and had a quick poke around but nothing was obvious. The bike stalled as I stopped and was hard to start again. I didn't want to hang about on the Hard Shoulder so limped a mile to Oxford Services where I had a proper look.

Again nothing was obviously amiss. Throttle cables were properly seated, the coil packs were replaced a couple of years back and look in good shape, plenty of fuel (around half a tank), fuel pump sounds like its priming on key turn and the pump itself was replaced less than 18 months and about 12 to 15k ago. No blown fuses, no snagged fuel line, tried the Motronic reset as a last-ditch attempt but made no difference. Since pulling in to the services I've not been able to start the bike. Plenty of juice in the battery, she's turning over ok but not even coming close to firing up.

Called the AA and I was (eventually) relayed home.

The Hall Sensor has been suggested as a possible culprit but I'm not 100% sure what that even does let alone where it is or how to test it – and I'm assuming the "test" will be to buy a new one, fit it and see if the bike starts!

A quick Google has thrown up other possibilities of water in the fuel, a blocked fuel filter, or a split fuel line inside the tank.

Any other pearls of wisdom? I could really do with getting the old girl running again asap!

 

[MikeO]

On my way up to the NEC Show on Saturday I had a problem with my 03 1150 GSA ('03, ABS, 57k) – cruising along at 70mph on the M40, I'd done about 60 miles from home when there was a sudden loss of power and the bike slowed.

I throttled on a bit and it made a terrible racket, sounding and feeling like it was running on one cylinder.

I pulled straight over and had a quick poke around but nothing was obvious. The bike stalled as I stopped and was hard to start again. I didn't want to hang about on the Hard Shoulder so limped a mile to Oxford Services where I had a proper look.

Again nothing was obviously amiss. Throttle cables were properly seated, the coil packs were replaced a couple of years back and look in good shape, plenty of fuel (around half a tank), fuel pump sounds like its priming on key turn and the pump itself was replaced less than 18 months and about 12 to 15k ago. No blown fuses, no snagged fuel line, tried the Motronic reset as a last-ditch attempt but made no difference. Since pulling in to the services I've not been able to start the bike. Plenty of juice in the battery, she's turning over ok but not even coming close to firing up.

Called the AA and I was (eventually) relayed home.

The Hall Sensor has been suggested as a possible culprit but I'm not 100% sure what that even does let alone where it is or how to test it – and I'm assuming the "test" will be to buy a new one, fit it and see if the bike starts!

A quick Google has thrown up other possibilities of water in the fuel, a blocked fuel filter, or a split fuel line inside the tank.

Any other pearls of wisdom? I could really do with getting the old girl running again asap!

If you were sure it was firing on one cylinder (and it was always the same cylinder ) then the above will not produce that symptom.

If it's a fuel problem to only one cylinder then your fault can only lie in a small area of the fuel system - between the pressure regulator (probably wrong terminology) and the injector. Most likely a blocked injector.

That's if it's a fuel problem and if it only affecting one cylinder.

I'd try all the normal stuff - spark to both sides? Fuel to both sides? and then look at the spray pattern on each injector (do this with the plugs out and in a well ventilated and flame free area, putting the injector into a jam jar or similar to catch the fuel - sorry to state the obvious). You should get an even fan shaped spray from the injector. Anything else, then give it a blow over with an air line to clear any blockage.

Good luck...

Mike

 

[Robster]

Thanks Mike, I'll see if I can follow your suggestions tonight when I get in from work.

Just seen another "rough running" thread where water in the fuel/blocked tank filler vent thingy was suggested and/or to blame. My little vent has been blocked for a while and I've tried all sorts of things to clear it - and there has been a little water in there too which I've carefully mopped up every time I've filled up.

I suppose it's possible some water has got in the tank though /

 

[Womble]

Do a compression test on both sides as well, just to make sure that the valves are OK.

 

[DrFarkoff]

Do a compression test before you do anything

Perhaps a burned valve ??

 

[luke scott]

Blocked fuel filter in the tank ? Happened to mine last year. Sounded just like your problem.

 

[Steptoe]

I throttled on a bit and it made a terrible racket, sounding and feeling like it was running on one cylinder.

Do a compression test on both sides as well, just to make sure that the valves are OK.

Do a compression test before you do anything

Perhaps a burned valve ??

Yep, i'm afraid it points to a valve problem, which i'm seeing more frequently as the bikes get older. . As said, a quick compression check will let you know.

 

[Fanum]

It does sound very much like the way mine went when a couple of valves dropped into the pot

Pull a plug out.....this is what I found when I did:

 

[Robster]

Yep, i'm afraid it points to a valve problem, which i'm seeing more frequently as the bikes get older. . As said, a quick compression check will let you know.

It does sound very much like the way mine went when a couple of valves dropped into the pot

Arse. That sounds expensive!

"Quick compression check" – excuse my mechanical ignorance, but how would I go about that?

 

[Womble]

You need a compression tester, either borrow one from a mate or they are cheap enough to buy. It's just an air pressure gauge that tells you how well the combustion chamber is sealed. However, pop the plugs out - if its Fanumated, there's no need to check the compression.

Best of luck - hope it's something simple!

 

[Fanum]

Arse. That sounds expensive!

"Quick compression check" – excuse my mechanical ignorance, but how would I go about that?

Your best bet would be to take it to any garage that has a compression test kit.....basically it's a plug that screws into the spark plug hole with a pipe and a gauge on ot......you turn the engine over and it tells you what pressure is inside the cylinder.

You compare it to the other side and against the 'known' pressures it should be at.

If you undo the spark plugs though and have a look at their ends, if one of them looks mangled, there's little point in getting a compression test- you'll already know.

You should have the tools to whip out the plugs in the bike kit and it'll only take you a couple of minutes

 

[Robster]

You need a compression tester, either borrow one from a mate or they are cheap enough to buy. It's just an air pressure gauge that tells you how well the combustion chamber is sealed. However, pop the plugs out - if its Fanumated, there's no need to check the compression.

Best of luck - hope it's something simple!

Cool, I know a man who may just have one of those!

But in the meantime, yeah, I'll pull the plugs tonight and hope for the best

 

[Flipfly]

Arse. That sounds expensive!

"Quick compression check" – excuse my mechanical ignorance, but how would I go about that?

Quick test would be to take out the plug, pop ya finger in, turn the motor over and if you lose the end of your pinky then your compression is good

Alternatively, machine mart sells a compression tester for reasonable money

Surely the first thing to check would be if you have a spark

No spark would be point to a downed coil or a knackered hall sensor No spark both sides would be more than likely the hall sensor.

The terrible racket would cause me to lose sleep I think.

 

[Robster]

Quick test would be to take out the plug, pop ya finger in, turn the motor over and if you lose the end of your pinky then your compression is good

Alternatively, machine mart sells a compression tester for reasonable money

Surely the first thing to check would be if you have a spark

No spark would be point to a downed coil or a knackered hall sensor No spark both sides would be more than likely the hall sensor.

The terrible racket would cause me to lose sleep I think.

Yeah there is a spark there, at least on the side that I thought wasn't running... which only makes me feel worse!

 

[Flipfly]

Yeah there is a spark there, at least on the side that I thought wasn't running... which only makes me feel worse!

Yep, time to speak to St Eptoe to see if he has a spare top end (not) knocking around in the garage

Scrimminger may have a few too if Steppers ain't got one.

Eblag has a few, but always risky imho. Don't cry, shouldn't be too expensive unless you]ve been really unlucky. The good thing with Bm's is there are plenty of spares available.

 

[Steptoe]

Yep, time to speak to St Eptoe to see if he has a spare top end (not) knocking around in the garage

Scrimminger may have a few too if Steppers ain't got one.

Eblag has a few, but always risky imho. Don't cry, shouldn't be too expensive unless you]ve been really unlucky. The good thing with Bm's is there are plenty of spares available.

Might not need a new head. 99% of them only have a burnt valve. Simple and relatively cheap to repair.

Bills was a more unusual case of the engine playing ping pong with the valves.

 

[Johnwhit]

I had a burnt exhaust valve with a bite sized hole in it about 18 months ago, I downloaded the guide on this site and with a new valve and head gasket it went back together without any fuss.
I just needed to get a good torque wrench and one of those valve lapping kits and follow the instuctions.
Seemed like the end of the world but in the end wasnt that big a deal to fix.
I would get the compression checked and if you find no compression do a strip to investigate.

A good tip was to cable tie the cam chain to the sprocket so you dont loose your timing but the guide explains it better.

 

[Robster]

Thanks guys for all the advice.

Didn't have a lot of time to investigate last night, but I did pull the 2 upper plugs (Twin Spark model) and....


...they seemed perfectly normal, not covered in shrapnel like I feared they might be. Again, the bike turns over (and over and over and over) but doesn't even think about firing. At least in the quiet of my garage I can now hear that it all sounds pretty normal - apart from the fact it just won't fire.

So, I'm now going to start with the simple things and work forwards. I'm hoping (in a funny kind of way) that my blocked filler cap vent has led to water in the fuel and or the fuel filter has somehow become blocked. There's a filter and O Ring on order and we'll whip the tank off when that arrives and see what's what.

In the meantime if you've any other ideas then please share!