Motronic chip/plug 1100GS at high altitude?
 

I'll be leaving for a 6-month Asia trip in May on a 1100GS. I expect to encounter riding at higher altitudes.

What do I need to bring in terms of different Motronic plugs/chips? Or nothing at all? I'll bring a plug/chip for lower octane fuel.

Thanks,

Martijn

I haven't heard 1100s have suffered much on altitude sickness, the Motronic is controlled injection - it measures various variables and chooses the best suited. Usually it's more carb-equipped engines problem.

Indeed, i have very enthusiastic interests in your low-octane plug. Can you tell where to get it? Have you tested it, works well? Do you have KAT too on the bike, or found a way to skip it?

Let us know, cheers, Margus

Hi,

I ordered the low-octane chip at my local dealer. Have not received it yet, will keep you informed about the details.

I get the impression from searches as well that there is no 'altitude-chip'

Cheers

Martijn

THe motoric has an air pressure sensor - so it already compensates for changes in alititude (and weather pressure). It also measures air temperature, engine temperature etc.

I suspect you will get poorer fuel consumption with teh low octane chip, you should use it to find out (I think it will run rich). If it does run rich I'd only put it in where required so as to save some fuel costs (and give you the better fuel range).

hello Martijn,
I just rode from los angeles to ushuaia, with a 1995 R1100GS. I encountered high altitude and low octane fuel. I did't change anything on the bike, even left the catalysor on.
I did't have any problems with altitude, sometimes a little lacking in power due to the poor fuel.but not worth mentioning.
have a good trip,
Mark.

Many thanks for the replies. I just heard from my local shop that a 1100 does not have a chip for low-octane fuel. The 1150's do..

I go with your positive replies and see what happens on the road. Perhaps bring some octane booster just to be sure.

Cheers

Martijn

I just tested 91 octan in my 1100 with KAT, run through one TT tank 36 litres, over 600 kilometres. Checked the sparks after that - they were perfect, checked if there's any carbon build-up in piston head crowns via spark holes - they looked the same as i run on 95 or 98 octane. Performance difference running 91 compared with 95/98 - hardly noticable. In longer terms, maybe using some injection & build-up cleaners is an "selfe confidence" idea, indeed does't seem to be in a "must" list...

Thus sure i'd conclude 1100 eats 91 octane adequately well. Below 91 (85-89 octan?), don't know yet...

Cheers, Margus

[This message has been edited by Margus (edited 06 May 2005).]

After some 30K kilometers on the road here are some conclusions:

- The Motronic chip holds well for altitudes up to 5200 meter (you only go higher in the Indian Himalayas, up there I had to give all gas in first gear, it worked)
- Running even on 76 octane is no problem, however I have heard that long term your pistons will be damaged. Advice I got: run above 3000 rpm

Overall summary: the 1100 fuel system can go arounds the world without modifications.

Hope this helps for anyone who had the same question.

Martijn

I can confirm Martijn's facts.

My 1100 didn't had any problems on high altitudes in Zagros mountains in Iran, catalythic converter and lambda sensors were killed running thousands of kilometres low octane poor quality unleaded - but the bike worked just like there was no lambda or CAT. The reliable Motronic adapts with all the conditions, while you have to retune and hassle with carbs on many machines. So i'd vote for injection over carburation. And if you have any problems - just put the new spare injectors, they cost very little.

Good thing about the BMW's Motronic engine management is the "limp home mode" that disconnects all the sensors and sophisticated mixture calculations and the engine's fuel management goes into simple "basic mode". I never had to use it, but if you have any very serious fuel management problems, this option brings you forward on journey. Another good advantage for injection.

Cheers, Margus

I took my R65 up over 5,600 m in northern India, i put smaller jets in the carbs because i had them (didn't drop the needles though), but i think i could have got away without them. The bike lacked a bit of power and ran rich of course, but had no problems at all getting up and over. I did have to adjust the idle regularly.
With the altitude constantly changing over mountain passes, it's difficult to have the right carburation all the time. I think if a carb beemer can do it, the new ones should have no problem.
Sean

I took my R80 to 6000m in peru, dropped the main jet a couple of sizes and fitted hotter burning plugs, seemed to work Ok, problem with altitude is that the % of oxegan in the air drops so whatever you do to the mixture power will drop.
Fuel injection systems will measure the density of air so should adjust to altidtude than carb bikes, however the vacuum nature of a CV carb does privide some automatic adjustment for altidtude.

Charles

I STRONGLY recommend NOT changing to a hotter plug - first it is unnecessary, second it will make the engine run hotter, and it is already working harder and hotter. VERY risky. All you need to do is correct the carburetion/injection mix to compensate for altitude. Vehicles/cars/bikes/trucks sold in high altitude areas are ONLY adjusted for mixture.