what to do with poor fuel quality ???

**vincent danna** · #1 24 Mar 2002

hi,
we had a talk with viktor, we are going to opposite ways through ex ussr
so worries for sure with fuel quality
i drive a r100gs pd, he drives a dr400, and i don't know what to do with poor fuel quality
i told him that the bmw takes almost anything
i have some filters to filter the fuel, to avoid "sheet" to go inside the carburator etc ...
i will maybe play with the carburator, what we call "richesse" in french

otherwise ???
any advice please ...

thanks a lot, safe travels

i'm leaving in a week, ready with almost anything, waouh :-)
http://vincent.danna.free.fr/

**Grant Johnson** · #2 25 Mar 2002

Vincent,

All you can do with poor quality fuel is filter it to make sure it's clean and nothing gets into the carburetor.

There are no adjustments you can make to the carburetor to compensate for poor fuel. Leave it alone, just pull the float bowls off occasionally to make sure it's clean with no water.

If it runs really badly, dump the fuel and replace it. If the bike is pinging badly (rattle in the engine) from poor fuel, you can retard the ignition timing a little. (Mark the ignition canister location so you can get back to the same spot, then move 2-3mm)

Otherwise keep throttle opening lower and revs higher to reduce load.

Good luck, have a great trip!

------------------
Grant Johnson

One world, Two wheels.
www.HorizonsUnlimited.com

**vincent danna** · #3 25 Mar 2002

grant,
thanks, that's what i thought a bit

is there any solution with low octane fuel ?
or that's the same replies ?
maarteen talked about octane booster, what do you think ?

thanks,

**Grant Johnson** · #4 25 Mar 2002

Low octane is what causes ping. Octane booster - if you have room, sure, but you can only carry so much. I wouldn't bother.

------------------
Grant Johnson

One world, Two wheels.
www.HorizonsUnlimited.com

**mmaarten** · #5 26 Mar 2002

Hai,

To bad you can't take a trailer with the stuff (octane booster).

Actually, what I ment to say Vincent:
You get a tank full of bad fuel, low octane that is, No problem, just drive easy, little throtle, high rpm and it will probably go OK. But... then, after 2 weeks of driving like that, you get to a big mountain... and you need to go over it. Unfortunatly you can't make it with little throtle

and the engine sounds like a drumband... then it's time to get the little bottle of "octane booster" and through it in.

It might just help you to get on top of that mountain.

Ofcourse... it's only theoretical, I never had that problem. (I don't even know how good the stuff really works)

Maarten

**vincent danna** · #6 27 Mar 2002

hi,
thanks for your replies
i think i go without octane booster and be careful with the fuel, try to get the best i can

safe travels
http://vincent.danna.free.fr/

**Gerd** · #7 2 Apr 2002

hi vincent,

to prevent or minimize the pinging you can replace the original cylinder-foot-gaskets. Your BMW-dealer should have (or could order) thicker ones, designed specially for the 'bad-fuel-problem'. they are about double as thick as the originals and lower the compression of the engine. this minimizes the problem but of course (nothing's for free) lowers also the power of the engine.

to change the gaskets is not a big deal, but you will need a torque-wrench to tighten the cylinder- and head-bolts again with the right torque. i think you would find a torque-wrench also in a russian garage, but I would recommend to do this work in france, so you can do at a proper, clean and well equiped working space. anyway you should set ignition a little bit 'later' than original and of course use filters and clean or replace them regularly.

You could also get a double-ignition (with two pluges for each cylinder). this also lowers the risk of pinging, but it's an expensive work and you dont have no time.

before i changed my BMW engine (R60/5) completely (with no 'bad-fuel-problem' never again), i did this foot-gasket thing and it worked fine with bad fuel in the middle east and egypt (in the late 80s).

long may you run
gerd