Surging- quick fix?

[Gav]

I know that the hunting/surging thing has been discussed at length but I don't have a lot of time to search. My bike is an 1150 twin spark and it has recently developed this problem during a trip. I'm currently in south east Lithuania and wondered if there was a quick soloution I could try. The bike is fine under load on an open road in 5th or 6th but at lower speeds in low gears which is what I am using on the back roads it is a right pain. The throttle bodies were balanced just before the trip.

I thought that the twin spark models weren't supposed to do this. Would changing either the main or secondary plugs help?

Appreciate any info.

Cheers

Gav

 

[roddy]

the only really quick things I could suggest is,

are both throttle cables seated correctly with the ends of the cables outer sheath sitting correctly in the knurled knobs on the side of the TB's or if you have something to balance the throttle bodies (TB's) with you could tune out the surge to a different position in the rev range so you don't notice it as much,

Otherwise the only real solution after doing a quick search seems to be checking all valves, rocker play and then balance the TB's

 

[Gav]

Hi Roddy

Thanks for the reply.

I'm not able to balance the throttle bodies or do anything concerning the valves. I'll have a wee look at the throttle cables but I'd be surprised if this was the problem.

Cheers

Gav

 

[Big Lad]

Replace the coil/spark plug cap, that is the most likely NON- PETROL cause on a twin spark. Also the easiest to look at. Though not on a touring trip in Eatern Europe!

 

[(RIP) Bin Ridin]

Not the old stone-under-the-throttlestop, by any chance?

 

[GEOFFREY DEACON]

surge

Try looking at the grades of fuels you are useing rescently and the quality?,
Also look at you Throttle switch to see if its been disturbed,?.

 

[Gav]

Thanks for the replies guys. As I thought, the cables are seated correctly. I've had this before and the bike tends to pull on one cylinder rather than hunt.

I'm now in western Lithuania (that wee bit closer to home). Don't think there are any stones lodged in the throttle stop. Would this not cause eratic running more of the time and especially at tickover?

I had wondered about quality of fuel but dismissed this as I thought these things were supposed to run on almost anything.

Thought I might have felt it missing when overtaking cars in 5th and 6th. Fuel starvation? Weak spark?

I'm thinking of calling into a B.M.W. dealer in Sweden when I get back across the Baltic and see if there's anything they can spot.

Thanks again.

Gav

 

[Straypuss]

Firegus changed all the plugs..made a big difference said it felt like a different bike.

 

[Gav]

Thanks again guys. I'm now in Denmark. It turned out one of the coils had a crack in it- it didn't look too good. A new coil and a couple of new plugs and it seems to be running better. The belt was a wee bit loose so that's been tightened as well. It's due its 24000 mile service in less than 1500 miles so might be even better after that.

Gav

 

[Timolgra]

Glad to hear you're sorted Gavin

 

[Gav]

Me too Tim.
Seems Big Lad was right. The bike is smoother now and generally more enjoyable to ride. I popped into a place in Copenhagen which deals with B.M.W.s and the guy was pretty quick to suss out it was the coil. He had one in stock as well. And the other guy at the place gave me his big giant Danish sausage to keep me going on the rest of the trip. You want to see the size of this thing! Mind you, it's starting to stink out the pannier a bit.
Have you found an S.E. to replace your bike, Tim? Didn't think you'd have gone for a bike with A.B.S..

 

[Timolgra]

yes Gav, I found a beut of an SE with only 2k miles on the clock and month later it has 5k miles on the clock, I love it.

Jury is still out on the brakes, they are good but am concerned about reliability.

When I sold the first 1150 i had, the coil packed up just after selling with the same symptoms you described

Regards tim