1150 GS not as fast as it used to be

[robc]

Morning all,
Just a quickie.

My 1150 GS used to do 125mph on the flat. That was when it had done <40,000 miles. It's now done 66,000 and it will do only 110. I don't want to ride at those speeds I just happened to notice it the other day.

Is it just a case of some horses escaping now the engine is approaching middle age?

Plugs and air filter are new. I've always used the same grade & brand of engine oil. Brakes are not binding. The valves are adjusted to the minimum tolerances but I'll be checking them again this service. I've always carried the same top box and I'm not 10 stones heavier than last year

Maybe I just need to replace the fuel filter and clean the injectors? The bike is running perfectly otherwise.

Any thoughts?

Regards

Rob C

 

[Stewart H]

My 1100 has done more miles than that and still goes as quickly as ever (pile of camping gear and panniers full of tat notwithstanding) it probably needs an "Italian decoke"

 

[Wegby]

Try running a compression test on each of the cylinders to see if you're losing compression - either through the rings or by the valve seals.

My 1150 started to run slightly lumpily (although it was at 101k) and was losing about 20% compression through the valves. The heads were removed (not by me), new valve guides installed and replaced and it's as tight as the proverbial *****man again.


***** replace with nationality as appropriate...

 

[Pip_UK]

Hi Rob, at high speeds, the increase in drag turns the air to treacle. Differences in wind speed and direction, and what kit you're wearing may be a contributory factor to flat-out speed.

Also, how may pies you ate between mile 40,000 and 66,000

 

[robc]

Clothing same as before. Little or no headwind at the time. Even downhill it struggled to get past 110.

A compression test sounds like a good idea. I'll see if my local fixer upper can do it. I've not given him much of my hard earned cash yet this year.

Regards

Rob C

 

[davegs]

110?, obviously worn out sell it to me for a tenner

 

[Wegby]

Also, how many pies you ate between mile 40,000 and 66,000

Must be why mine struggles to get above 90 these days...

 

[andybharris]

I had an R850r with 142,000 miles on it,,, it ran better and faster with these miles on then it did with 42,000 miles. second gear whent at 110,000 miles though

 

[hops]

Morning all,
Just a quickie.

My 1150 GS used to do 125mph on the flat. That was when it had done <40,000 miles. It's now done 66,000 and it will do only 110.......

Any thoughts?

Regards

Rob C

Try selecting fourth gear, works for my blackbird

 

[STUBBS]

touratech items weighing it down

 

[robc]

Nope. Nothing added to my bike to make it look like it'll go round the world and yet never will. It just looks like it *has* gone round the world. Maybe there is 50kg of crap to wash off.

I did try dropping down to 5th to see if that made a difference but 110 is about 7,000 RPM so not much left there.

My local spanner man says he can do a compression test for me.

It's not really a big deal and I can live with it. If there is a problem that needs attention in the future I'd rather know about it.
The only time I notice this is a problem is when opening the throttle in 6th on a long drag of a hill doesn't have much effect.

It's only a machine and machines eventually wear out. Ho hum, such is life.

Regards

Rob C

 

[Keith Chapman]

Stretched throttle cables ?

 

[robc]

Stretched throttle cables? Seriously? That had never occurred to me.

Regards

Rob C

 

[Packer]

I'd have expected low compression to be more of an issue at low revs than high. Normally makes starting difficult.

 

[david a hall]

Just as a side note can any one else claim 125mph out of an 1150, bearing in mind this is a public forum so all speeds obviously were achieved on suitable race track or similar venues. and was this backed up by your sat nav. in fact lets hear the fastest you have ever gone on a stock 1150.

 

[Packer]

Just as a side note can any one else claim 125mph out of an 1150, bearing in mind this is a public forum so all speeds obviously were achieved on suitable race track or similar venues. and was this backed up by your sat nav. in fact lets hear the fastest you have ever gone on a stock 1150.

The short straight at Knockhill starts uphill, I could only manage 115mph before braking for the right hander at the end.

Don't have pratnav

 

[Grim Rider]

Just as a side note can any one else claim 125mph out of an 1150, bearing in mind this is a public forum so all speeds obviously were achieved on suitable race track or similar venues. and was this backed up by your sat nav. in fact lets hear the fastest you have ever gone on a stock 1150.

My Garmin 2610 (only ever used on the GS) is currently showing a highest speed of 169mph

(this may not be entirely accurate - it once showed 865mph, but that was on the autobahn where there was no speed limit....)

 

[peturley]

my adventure does 200kph on the speedo (125) dont believe it though,
logbooks in germany have to put the max speed in, if you get caught going any faster the cops will know you modified your bike, gs1150adv top speed is 192kph.
speedo's are shit, fit a sat nav and check the speed on that.bet your speedo is 10 mph out at 120

 

[The Grey One]

Sometimes they are useful

The short straight at Knockhill starts uphill, I could only manage 115mph before braking for the right hander at the end.

Don't have pratnav

Then you were probably doing about 105 then if my GS speedo is anything to go by. SatNav gives a very accurate speed, tested mine against two calibrated police bike speedos ( I was on a Bike Safe weekend honest) My speedo overeads by about 10% ie just slightly less than the legal maximum. First day of the Bike Safe weekend I used the bike speedo and was criticised for going too slowly! Second day I used the Sat Nav-screen with big mph figures and was spot on even when keeping to the officer's "not much over 90 eh" request!

Fastest recorded on my Sat Nav was 110mph-two up plus luggage-sustained for 30 mins on a German autobahn. We had come from the Italian lakes over the Alps and were heading for food and beer with friends near Stuttgart. Took ages to get over the mountains, we were running late so I wound it up and went for it-110 was it,full-throttle and just sit there. I have the optional lower 6th gear so I expect others to have gone faster.

Beware though that the speedo reading is about as honest as a politician

John

 

[Styve100]

One thing that can affect speed is HT leads losing some volts, leaking out of dodgy bits of the HT lead, HT is a funny thing, also the coils on the main plugs can be afected by water, mine was ony running on the aux plug on one side when I got it, made it back fire a lot, surge and obviously cut the max speed, although not really tried max speed too much yet, scares the hell outa me!
But basically throttle cable stretch and HT loss to the plugs.