Hesitation under acceleration 1998 R1100GS

[Teamin]

I am sure this has been covered but I can not find any direct posts.
Today I took the bike out and when I went to overtake a car and accelerate hard it was as if the bike came off a cylinder.
If I accelerate slowly then it is fine,
I did notice that one of the throttle body cables is slightly frayed ( which I will replace )
What else should I check and how?
Thanks in advance

 

[DrFarkoff]

Was it 2nd gear to third by any chance ??

My 1100RS had that problem it was a bent selector that would jump and give you the impression of a misfire or stall But Usually more on the Pre 97 bikes

Drain hole in Filler neck Clear and no possibility of water in fuel

Degrading fuel from last use and clogging filter

Split at U bend bit at the pump but that usually stops the motor altogether

I have seen the hoses on earlier bikes degrade and crumble and make their way in through the sock that is usually knackered by now

Coil for a crack I had a few that were cracked

Sparkleads /plugs

throttle position sensor Setting/Operation

Also Ignition lead to the main loom for damage fraying But you should have things go dead

 

[Teamin]

Seems to be in any gear, ( i think ) but certainly 3rd,4th and 5th.

Excellent, plenty to start on

Was it 2nd gear to third by any chance ??

My 1100RS had that problem it was a bent selector that would jump and give you the impression of a misfire or stall But Usually more on the Pre 97 bikes

Drain hole in Filler neck Clear and no possibility of water in fuel

Degrading fuel from last use and clogging filter

Split at U bend bit at the pump but that usually stops the motor altogether

I have seen the hoses on earlier bikes degrade and crumble and make their way in through the sock that is usually knackered by now

Coil for a crack I had a few that were cracked

Sparkleads /plugs

throttle position sensor Setting/Operation

Also Ignition lead to the main loom for damage fraying But you should have things go dead

 

[DrFarkoff]

Seems to be in any great, ( i think ) but certainly 3rd,4th and 5th.

http://largiader.com/tech/oiltrans/

Read down at "My bike 'skips' in third gear...

 

[Teamin]

It feels more an electronic problem or fuel starvation.

 

[theoneandonly]

how about ...break and make , all your connectors , electric ones ...costs nothing but time . includes checking nipples on plugs ...they can come loose. don't forget relays , battery and fuses too.

 

[GORILA]

I would advise checking/ changing one thing at a time, otherwise you wont be sure of the cause. If you have a frayed throttle cable I would start there as that would be a very likely cause. Also when removing the cable junction box you will get the chance to check all three throttle cables and to clean the box itself and lube with silicone spray.
Then test your bike. If you still have the problem I would start checking your electrical or fuel components one at a time again.
As well as all the other things already mentioned, I would also suggest checking your HT leads. You can check their general condition visually, but also compare the wire resistance with a multimeter. Both wires should have similar resistance to one another. They can break down internally through corrosion. Motobins sell the enduralast silicone leads which are very good quality at a good price.
Hope this helps...

 

[Steptoe]

.
Today I took the bike out and when I went to overtake a car and accelerate hard it was as if the bike came off a cylinder.
If I accelerate slowly then it is fine,
I did notice that one of the throttle body cables is slightly frayed ( which I will replace )

I doubt the frayed cable has anything to do with it, that would be causing a problem all the time, and 99% of the time the revs stay high and it won’t drop down to idle speed. But replace it anyway before it becomes unrideable..... does your problem happen every time you accelerate hard ? or is it intermittent ?

 

[Teamin]

Every time I accelerate hard. But if I take it easy, then it accelerates fine.

 

[fox889]

Fuel starvation........blocked filter?

 

[theoneandonly]

Fuel starvation........blocked filter?

nah . not unless it's full of water.

 

[DrFarkoff]

Every time I accelerate hard. But if I take it easy, then it accelerates fine.

What was the last thing you did to the bike before it started this ?

Or did it start after being laid up for sometime and on your first use

 

[mikeyboy]

My 1st thoughts would be HT problem,
Spark plug gap too small.cracked plug ceramic,tracking plug lead or coil.
Gap plugs
Inspect leads etc
If poss try revving hard in a dark workshop you may get to see the tracking.

 

[Teamin]

I replaced the tank, and used the internals from the original tank. Initially I was thinking that I had pinched the fuel line. or a dirty filter.
I will check the resistance in the leads and also try reving it in the dark.
QUOTE=DrFarkoff;5979565]What was the last thing you did to the bike before it started this ?

Or did it start after being laid up for sometime and on your first use[/QUOTE]

 

[Steptoe]

Measure the resistance across the two injector body electric terminals... they should both measure around 16....

Had a few bikes in over the years running rough and hesitating due to the electric connectors in the injector breaking down.

 

[Teamin]

Steptoe, any pointers as in how I do that.
I know how to measure the resistance with a multimeter, but where do I measure from.

 

[Teamin]

I started the bike tonight and it revved out with no problems, so it seems to be under load when it happens.
Lights off and no sign of tracking.
I am going to take the tank off tomorrow and see if there is anything obvious.

 

[DrFarkoff]

Steptoe, any pointers as in how I do that.
I know how to measure the resistance with a multimeter, but where do I measure from.

On the injector bodies between the two terminals basically one probe to each

Remove the Ignition leads and check the ends and the length for cracking / perishing / Shorting on the frame

Check the Ignition coil for cracks or splitting

Check the plugs for gap and fouling

 

[Teamin]

Just measured them and they are both 15.4
Going to take the tank off and measure the HT leads.
Just filled the tank full of fuel too.
Plugs next also

Measure the resistance across the two injector body electric terminals... they should both measure around 16....

Had a few bikes in over the years running rough and hesitating due to the electric connectors in the injector breaking down.

 

[Teamin]

Ok so one lead was 6.090 and the other lead was bouncing all over the place anywhere from 3.010 - 9020
So I will order up new HT leads.