fuel query

[dhanda]

Hi all
Just had a worrying moment after reading that early k-bikes ran on leaded fuel.
Bike has done 48k miles and runs really well with CO at 2-2.5% .
I found a site showing the start of unleaded fuel chassis numbers and mine is earlier to that , so wanted to know if there are any proven additives that can be added.
Also it could be possible that the bike has had hardened valve seat conversion at some time in it's life.(thinking this as it runs so smooth)

[TimTyler]

How about telling the forum which bike you have and providing a link to the leaded fuel thing you read?

[wmax351]

Theoretically, early K's were designed for leaded fuel. However, I really haven't heard of any valve recession issues. Keep an eye on the clearances, but I don't think its much of an issue.

[dhanda]

Thank you for your comments , maybe it wont be an issue as the bike has done 48k so far and seems to run ok.
the bike is registered Jan 1984 k100rs , but according to the chassis details it was made in the last week of November 1983.

[programmasters]

leaded fuel was completely banned in Germany as of 1988, since the ban was in the works since 1982 i highly doubt it if these bikes were engineered to run on leaded. never heard of it, but you never know

[Inge K.]

The changeover to unleaded fuel was early -85 (euro models).

[programmasters]

Wool BMW was late to the unleaded show, did not know that, however a wise man on this forum once wrote to me, put oil in it, put fuel in it, ride it... I highly doubt that if you have driven 48k miles on unleaded any problems would arrise in the future related to the unleaded fuel. You can put in an additive so the fuel becomes leaded since leaded fuel is hard to come by, however check if you have a cathalyc converter because leaded fuel and cathalyc converters don't mix. Soo that would be a big indicator, if you have one do not put in leaded fuel, if you don't have one, it's up to you. I would say good quality fuel is important, here in Europe I put 98 in my bike but I think your highest octane fuel is 93 so use that and you will be ok

[racinrich]

programmasters is that fuel 98 ron  rated or 98 r+m ?

[programmasters]

Right sorry, it's 98 ron so that would be 93 r+m/2. That fuel has a higher knocking resistance, so if you were afraid of knocking take the 98 europe, or 93 usa. Now i don't know why but bmw (cars) advises 93 r+m/2 in usa while here in europe they say 95ron is just fine

[dhanda]

The fuel I been using is shell v-power which is rated at 100 Ron, but a new shell v-power nitro is available in the UK, that's rated at 102 Ron.
in the following link below you will see that the last piece of data under engine section gives chassis number change over from leaded to unleaded.

http://www.bmbikes.co.uk/specpages/K100RS2valve.htm