1150GS Power Problems

[nock]

Hi Guys - I'm new to the forum so if I ask any stupid questions please bear with me.

I've just purchased a tatty 2002 R1150GS that has a few 'issues' mostly cosmetic, its the only way I've been able to afford one.

Its got 67k miles on the clock which I understand ain't that big a deal on these beasts, however the bike doesn't seem to be making enough power. The engine sounds 'flat' and 'muffled' and the heads sound a little rattly which leads me to think the valves clearances need checking or the piston rings are shot.

When riding the bike it stalls unless I give it a big handful of revs and feather the clutch (worst in 1st gear but needs it less and less as you go up through them). When the clutch is out the bike has reasonable performance mid-range but not as much engine braking as I'd have expected. When I take it into the upper end of the rev range it tops out early and doesn't want to go any faster.

The previous owner told me he'd had the throttle bodies professionally cleaned, a new fuel filter, a full service (January) and strangely enough also had the loom replaced. It was stolen and recovered recently and I think the scally's that nicked it probably tried to bump start it. I know ECU's on injected engines don't like being bump started and wonder if there was a way I could reset its memory (I have solved a similar problem on my car recently that was cured by following a Haynes manual ECU reset procedure)

I intend to buy a compression tester tomorrow as I think that the valves or piston rings may be worn, but I'd be really interested to know what your collective thoughts are on the problem before I start pulling it to bits.

Thanks

 

[MattW]

Welcome to the site

Ok. I'll start you off.

The most important thing is to work methodically - address one thing at a time or you'll end up chasing your tail and confusing things.

Get a haynes / clymer manual if you don't already have one. If it were me, I'd give it a full service (even though it's supposed to have had one already) - change the fluids, oil and air filters and plugs and check / adjust the valve clearances and rocker end float. Check the throttle body balance (either yourself or get someone else to do it). Then at least you've eliminated the easy stuff.

After this it'll need more investigation but do the simple things first - remember - be methodical and address one variable at a time - hopefully you'll get some pointers as to the most likely suspects.

Some things to think about:
Does it have a standard pipe and air filter?
Does it have any sort of power commander / has it been chipped?
Is the ccp (cat code plug) in the fuse box in place and standard?

Others will hopefully chip in.

good luck