Poor cold running 04 R1100ss, a cautionary tail!

Jelwin · Post by **Jelwin** » Sun Nov 25, 2007 9:13 pm

Poor cold running 04 R1100ss, a cautionary tail! Sorry this is a bit long!Sometime your own instincts are correct so my advice is don’t let others persuade you into taking a costly route like I did!

I changed my exhaust for a Laser system and three days later I started to have cold running problems; bike started Ok, but ran ruff until it was hot, sometimes stalling on the warm up. So I’m thinking something’s broke down, plug maybe? so taking first load of technical advise from “experts”, changed spark plugs, fuel, oil, air filter (BMW part), checked valves and yes balanced the throttle bodies, still same problem!

Now been running poorly for two weeks, took it to local BMW dealer who test rode the bike (hot) and said it was OK and a ruff idle was common for Laser systems. Not happy with this advice as it ran Ok for three days before the problem.

After a few more days poor running could not accept this was normal, it also seemed sluggish on one of the few long run I currently do, so checked in with my local tuning shop, they reckoned that I should check for error codes first. So bike booked into local BMW dealer for diagnostics, after three hours diags and they took it home over night, they reckoned nothing was wrong; however they only charged me for one of the three hours!

Been running badly for a month, now thinking seriously of trading it in for something reliable (Honda maybe). Ended up buying a CB1300 and keeping the boxer … I’ve had three years good running out of the boxer and it’s never a bad thing having two bikes!

Now it gets expensive, new advice, boxers run very lean with a Laser so go for a management system to sort it, Wundelich unable to get me one of there gismo’s after a week and half trying, Laser chip obvious way forward but would take another week, so booked it into the local tuning shop and rolling road for a power commander 111 and setup (PC111 not cheap for a boxer as it comes with a wide band Lamda sensor).

The rolling road showed 79.8 BHP at back wheel and running very lean, it also showed up a strange curve where, although it followed other similar R1100 power curves, the curve line itself was fussy! Obviously I was very disappointed as I would have expected nearer 90 BHP. The bike did run a bit better, but it seemed like when accelerating I was “pushing” it rather than the bike pulling me … if you get what I mean!

Decided to try out a few more checks and if I could not fix it myself …trade the b****d in. As it was a twin spark no one suspected plugs but thought injectors etc. Cleaned injectors, no difference, then decide to do a compression check, both pots showing 200 exactly, then decide to run it on each set of plugs, first middle plugs removed, run on lower ones and it ran peachy, and yes you can guess when running just on the middle ones it only ran on one pot … problem solved!

To make sure all was OK, put it back on the rolling road, now peak power up to 92BHP and mid range up by an astonishing 18BHP. Why the local BMW shop did not find it mystifies me, they reckoned it was it was an intermittent problem and when a coil goes down the usual signs are backfiring .. it was obviously not intermittent as the bike was consistently down on power during the rolling road runs and always ran crap when cold. The plug being down didn’t show up on the rolling road because the pick-up signal we used was before the coil and of course the lower plugs ran fine.

I’m sure there’s a moral in this storey, for me I should have kept with my hunch and followed the spark plug route through earlier, not listening to the logical should run as well on three and four comments!

mm_marquez · Post by **mm_marquez** » Sun Nov 25, 2007 11:14 pm

A fantastic story, but I just wanted to verify:

What did you mean by the engine running only 'on one pot'?

Does that mean only one plug was firing?

Because you said that the first thing you did was change the plugs (as well as the filters etc.), then I'm assuming that the problem lay with the the coils/ignition system etc.?

Cheers

Lars1974 · Post by **Lars1974** » Mon Nov 26, 2007 7:53 am

Hi Jelwin,

i have a 99 R1100s with Lasers and chip...the bike also got lennies air intakes and K/N filter...
i had mine Dyno'd and this is the outcome:

so as you can see the bike should make between 90-95 bhp on the back well with the mods...

hope this helps.

thx Lars

winger · Post by **winger** » Mon Nov 26, 2007 8:20 am

Don't get carried away with dyno figures guys,dif dyno's give different figures,as much to do with make of dyno as much as the bike.

Jelwin · Post by **Jelwin** » Mon Nov 26, 2007 4:14 pm

mm_marquez wrote:A fantastic story, but I just wanted to verify:

What did you mean by the engine running only 'on one pot'?

Does that mean only one plug was firing?

Because you said that the first thing you did was change the plugs (as well as the filters etc.), then I'm assuming that the problem lay with the the coils/ignition system etc.?

Cheers

Hello,

Yes sorry I should have said, it was the coil!

Regards

John