1981 yamaha special 850 lead gas???

Ok i got my bike a week ago.......the guy I got it from has been putting 93 octane gas in for like 10 years........but on the back of the bike it says "regular leaded fuel only" what should i make of it???

If the bike has been modifided, then it may need the 93. The worst case using 93 is wasting some money. Alot of folks use the higher octane cause it's said to be cleaner though too.

I don't think that anything bad is gonna happen using it.

I don't know the bike, but the biggest thing that sticks out from the post you made was "leaded". Has this guy been putting a lead additive in the fuel? Back then lead was added to the gas as a fuel additive to provide lubrication for the valves, and can be especially necessary in bikes or cars that use solid lifters. You need to find out if he's been adding lead to the fuel, and if so... keep adding it or you'll tear the motor up. If he hasn't been adding it, then the motor has probably been modified, or may not even be the original motor.

I had a 1980 Yamaha XV 750 Virago that I put over 40,000 miles on and all I ever used in it was regular unleaded and had no problems with it, I also use regular unleaded in my 1980 GL1100 Gold Wing have over 30,000 on this bike since I got it 15 years ago again no problem. I think you will find MOST bikes made after mid 70's will operate fine on regular unleaded,although you may find some models from that period that recomended Premiun unleaded. I think it was in early 70's that we started using unleaded gas. I do use lead substitute in the gas for my old snow blower,it is a early 1960's model, long before unleaded was thought of.
Jim RIDE ON

Same here, I have a 1980 xs 850, have driven it 30 K and use regular gas. The bike has nearly 40 k and I haven't noticed any problems

Good point BigWater, but in the Late 70's early 80's mot of the Japanese manufacturers started installing hardened valve seats and this is not an issue. On Harley's and English bikes you are right. Without using an additive, the valve seats will be hammered and will eventually need costly replacement with hardened seats and a full valve job.

He may have been using the higher octane gas to reduce the pinging effect as the older bikes had higher compression ratios and teh regular gas of years past had a higher octane then todays 87 octane regular unleaded. If I am not mistaken, the regular of years past had the same octane rating of the mid grade unleaded's of today.

On Harley's and English bikes you are right. Hehehe... Learned that the hard way. I had a '73 650 Triumph Tiger with solid lifters in it. I bought it around '82 when unleaded gas was starting to become "normal". That thing screamed like a banshee, but every once in a while I'd dump the throttle and it would just bog down on me. No accelleration under power at all. Pull the heads off, and inspect them. No exhaust valve guides. WTF? No trace of them anywhere. I guess it was just blasting them out the tailpipe. I rebuilt those G*^D*#% heads every two months for a year before I talked to an old time Triumph mechanic about the problem and he laughed at me and told me it was from running unleaded fuel. By that point you couldn't even buy leaded gasoline anymore. I started putting a lead additive in the fuel and never had another problem with the top end.

Of all the bikes I've ever had in my life, That old Triumph was my most beloved. I still miss that bike to this day. Something about the rattle of the solid lifters was a soothing noise, and after all the times I had to wrench on it I knew it inside and out. I hope to run across another one some day when I get the time for a project bike. I'd love to restore an old '73 back to factory.

Beautiful bikes...

Hehehe... Learned that the hard way. I had a '73 650 Triumph Tiger with solid lifters in it. I bought it around '82 when unleaded gas was starting to become "normal". That thing screamed like a banshee, but every once in a while I'd dump the throttle and it would just bog down on me. No accelleration under power at all. Pull the heads off, and inspect them. No exhaust valve guides. WTF? No trace of them anywhere. I guess it was just blasting them out the tailpipe. I rebuilt those G*^D*#% heads every two months for a year before I talked to an old time Triumph mechanic about the problem and he laughed at me and told me it was from running unleaded fuel. By that point you couldn't even buy leaded gasoline anymore. I started putting a lead additive in the fuel and never had another problem with the top end.

Of all the bikes I've ever had in my life, That old Triumph was my most beloved. I still miss that bike to this day. Something about the rattle of the solid lifters was a soothing noise, and after all the times I had to wrench on it I knew it inside and out. I hope to run across another one some day when I get the time for a project bike. I'd love to restore an old '73 back to factory.

Beautiful bikes...


I went to school across the street from the local Triumph and BSA dealership. That was my first experience with bikes. Luckily we have some realy good "English" mechanics in this area. Helped a friend do a 650 Bonny. They are beautiful bikes.