1150's surge?

[Septic]

What is the cause of surging in 1150's single spark?
it really starting to do my nut in. I did a full service on it last weekend and adjusted the valve clearence's and the end flote but its still doing it
usually at 2500 rpm

 

[Steptoe]

Not serviced correctly.

 

[Deleted account 231211001]

I changed the tubes from the airbox to the injectors to those from an 1100RT. Someone told me about this, and when you take the originals out, you see that they're huge,( and they're a git to get oot!) and cause swirl in the airbox. Apparently this effect emphasisies the surging at steady throttle. The RT version is much shorter, and simply connects the airbox to the injector No swirl

Also, I read a post on ADV rider about synchronising all the valeves, not simply adjusting them. Linky http://advwisdom.hogranch.com/Wisdom/OVADv2.2.pdf

Bollix? Maybe, but as per usual disclaimer....it worked for me.

 

[John Armstrong]

What is the cause of surging in 1150's single spark?
it really starting to do my nut in. I did a full service on it last weekend and adjusted the valve clearence's and the end flote but its still doing it
usually at 2500 rpm

It's old tech, when it's working all is fine, if it doesn't, hit it with a hammer / metric adjustable

Or update the bike and get a 1200, and possibly a whole new set of things to annoy / confuse / irritate / enjoy.

 

[bladerunner]

I changed the tubes from the airbox to the injectors to those from an 1100RT.

Wierd!
I solved the surging on my RT1100 by swapping its tubes from RT to GS! Worked a treat!

Simon

 

[Rob Farmer]

Septic,

How did you balance the throttle bodies?

 

[Lord Snooty]

Try resetting your TPS voltages.

 

[Septic]

Septic,

How did you balance the throttle bodies?

i havent i was going to take it to blue bell

 

[davegs]

Intake tubes.

I fitted g S tubes tyo my 1100rt and this gave as [promised more urge in the mid range and this really did work, blasted up a hill in third much better. The only time I've experienced surging was on a test ride of a 1200 gs on launch day. Obviously wanted setting up but it really was bad and any who do have a problem.
dave (yellow fastest colour non-surging 1150) GS.

 

[Phil Thomas]

Until the throttles are balanced propoerly it is difficult to draw any conclusions.

Brass by pass screws at tickover then cables for the pickup. Plugs can also have an effect - at the moment I am using Champion EON 2 in my R1150RS.

Best of luck,

 

[Steptoe]

I did a full service on it last weekend

i havent i was going to take it to blue bell

As i said, not serviced properly

 

[Septic]

well your a great help arnt ya.

 

[Steptoe]

well your a great help arnt ya.

How big do you want it typed - Oil change doesn't stop surging

IT'S NOT BEEN SERVICED PROPERLY, WHEN THE THROTTLE BODIES HAVE BEEN BALANCED IT MAY NOT SURGE.


Waste of time suggesting anything else until then.

 

[iletts]

Septic, what Steptoe and a couple of others have alluded to is that you will need to balance your throttle bodies by setting correct idle conditions, (including checking/resetting TPS and adjusting air by pass screws), and then adjusting right throttle cable to balance throttles at 3k ish revs. if your throttle minimum stops have been messed with, then you may have to reset those using 'zero to zero' technique. That should sort any surging. It's all pretty well documented here and on advrider, if you can do tappets then you can do the rest if you have a DVM and twinmax or something similar to measure/compare intake depression.

 

[Septic]

Thanks for all the replys guys but the original
question still stands

WHAT IS THE CAUSE OF SURGING?

 

[iletts]

Thanks for all the replys guys but the original
question still stands

WHAT IS THE CAUSE OF SURGING?

I think someone put a technical description on advrider, but it boils down to mismatched combustion between the cylinders, with one getting more fuel than t'other, making it it accelerate, then the underfuelled one deccelerates, then the overfuelled one accelerates.......you get the picture

 

[Steve]

I think someone put a technical description on advrider, but it boils down to mismatched combustion between the cylinders, with one getting more fuel than t'other, making it it accelerate, then the underfuelled one deccelerates, then the overfuelled one accelerates.......you get the picture

Or to put it another way (as everyone else already has), poor or incomplete servicing.

 

[Rob Farmer]

Thanks for all the replys guys but the original
question still stands

WHAT IS THE CAUSE OF SURGING?

Now thats a question.

Build yourself a manometer for a few quid (do a search) and balance the throttles bodies properly. The chances are a BMW dealer won't spend the correct amount of time thats needed and will make a complete hash of it:- thats my experience anyway.

I've got a pile of vacuum gauges and various electronic devices that all claimed to be the best and all turned out to be shite. The only thing thats ever worked properly are the original mercury filled gauges and the home made manometer.

A deccent set of gauges or manometer will show you if you have a balance problem and where the problem is if you have.

Change the spark plugs to Champion Eon 2.

Make sure the throttle cables are sound and adjusted properly. The BMW service schedule suggests they should be changed every 18k.

I could be here all day but a G&T has my name on it