Guest Posted March 20, 2013 Share Posted March 20, 2013 HI, I'm a new member so this may have been discussed to death, so sorry in advance.I have a 1982 BMW R80RT. The bike has been off the road for 13 years with the original LEADED fuel in the tank.Does anyone know if I can use Unleaded in the tank or if I require mods done to the valves etc, or if adding additive to the fuel best way to go. Thx in advance. Quote Link to comment Share on other sites More sharing options...
Ricky Posted March 21, 2013 Share Posted March 21, 2013 I'll probably get my head bitten off for attempting to tell you but I think I've read that you need to remove the cylinder head and replace the valve seats with hardened ones and this can be quite expensive and if you're using only for sunny weather stick to additives otherwise you'll have to fork out for the new valve seats...I'm only saying what I think I've read.. What do I know I'm 16 =p Quote Link to comment Share on other sites More sharing options...
Guest Posted March 21, 2013 Share Posted March 21, 2013 I'll probably get my head bitten off for attempting to tell you but I think I've read that you need to remove the cylinder head and replace the valve seats with hardened ones and this can be quite expensive and if you're using only for sunny weather stick to additives otherwise you'll have to fork out for the new valve seats...I'm only saying what I think I've read.. What do I know I'm 16 =p Thx for advise. Will keep reading. I read somewhere it will be ok to use UNLEADED because the compression ratio is low. Whatever that means. Quote Link to comment Share on other sites More sharing options...
Ricky Posted March 21, 2013 Share Posted March 21, 2013 I'm probably miles off so I'd probably wait until someone who knows more to come online Quote Link to comment Share on other sites More sharing options...
Guest Posted March 21, 2013 Share Posted March 21, 2013 I'm probably miles off so I'd probably wait until someone who knows more to come online Thx anyway Ricky. Quote Link to comment Share on other sites More sharing options...
acting_strange Posted March 21, 2013 Share Posted March 21, 2013 try this..http://bmwmotorcycletech.info/valves.htmand this http://www.uniquecarsandparts.com.au/ga ... 20Fuel.pdfor this http://www.fixya.com/motorcycles/t90271 ... r100rs_run according to most replies the answer is yes but says to make sure you use Premium unleaded. Quote Link to comment Share on other sites More sharing options...
megawatt Posted March 21, 2013 Share Posted March 21, 2013 You will probably be ok with premium unleaded and octane booster. You may need to retard ignition a bit. I,ll ask a mate with an old BMW. Quote Link to comment Share on other sites More sharing options...
Joeman Posted March 21, 2013 Share Posted March 21, 2013 what ever the answer, drain the existing petrol out as it wont be much good after all this time... Quote Link to comment Share on other sites More sharing options...
megawatt Posted March 21, 2013 Share Posted March 21, 2013 Spoke to a BMW mate. He reckons before pre 1985 models would be at risk of damage. Motoworks do exchange heads for £200/pair if you do the removal/replacement. Octane booster would work if you don't do high mileage, but it's worth cleaning heads first and checking em after a few thousand miles. Google it, there's loads of info? Quote Link to comment Share on other sites More sharing options...
Guest Posted March 21, 2013 Share Posted March 21, 2013 The lead in leaded fuel was to lubricate the exhaust valves.. running unleaded fuel would run, but would severely damage your engine.. sharpish..Also unleaded fuel burns hotter, so an older "leaded" engine, would cook...You can get aditives to add to unleaded fuel, im pretty sure you can get it at most highly named petrol stations..i know Shell, sell it Or just LPG convert your engine.. Better burning, better performance, more miles Quote Link to comment Share on other sites More sharing options...
Tango Posted March 21, 2013 Share Posted March 21, 2013 I'm pretty sure I ran this on Unleaded.....1979/1980 R100/7.....Had it back in the mid '80's and I'm fairly sure it was unmodded..... Quote Link to comment Share on other sites More sharing options...
megawatt Posted March 21, 2013 Share Posted March 21, 2013 My mate has a 79 R100S running on unleaded plus Castrol Valvemaster additive. Quote Link to comment Share on other sites More sharing options...
Tango Posted March 21, 2013 Share Posted March 21, 2013 I thought that all bikes from the mid 70's onwards all ran on Unleaded? All my bikes certainly have.....from my first one, CD175 Honda I bought in 1975 right through.......and as I say I ran the R100 on unleaded and never heard any pinking from the engine....... Quote Link to comment Share on other sites More sharing options...
Stu Posted March 21, 2013 Share Posted March 21, 2013 Just stick some 4star in it Quote Link to comment Share on other sites More sharing options...
eastanglianbiker Posted March 21, 2013 Share Posted March 21, 2013 honda engines could run on unleaded from the early 70's as tango said and most others soon followed suite but i cant really help on bmw to be fair.........or what else was it they said you could do back then chuck a lump of lead block in the tank as they said that was meant to help Quote Link to comment Share on other sites More sharing options...
mattycoops43 Posted March 21, 2013 Share Posted March 21, 2013 I used to have a lot to do with running old landrover engines and mini engine (A type).As a general rule, any engine that has run for years on leaded will have a good layer of lead already embedded on the valve seats, so it will last for ages for occasional use. Unless you are planning on sitting on the motorway doing high mileage, I wouldn't worry too much about it, how many miles are you planning on doing?Yes, the timing will want changing slightly to compensate, but I have never heard of leaded engines running hotter? Most of them did because cooling systems back then were crap! If you use additive, you will have no issues. If it's a bike you plan on running for years and years, £200 for some modded heads is not a lot to spend.DO some research on the net though as from memory, some of the additives are a lot etter than others! Quote Link to comment Share on other sites More sharing options...
Stu Posted March 21, 2013 Share Posted March 21, 2013 DO some research on the net though as from memory, some of the additives are a lot etter than others! and some do eff all too I remember looking in to it when my dad had a petrol in his 72 land rover and there is some additives that do nothing there is a few out there that do what they are supposed to and are really cheap too Quote Link to comment Share on other sites More sharing options...
Guest Posted March 26, 2013 Share Posted March 26, 2013 try this..http://bmwmotorcycletech.info/valves.htmand this http://www.uniquecarsandparts.com.au/ga ... 20Fuel.pdfor this http://www.fixya.com/motorcycles/t90271 ... r100rs_run according to most replies the answer is yes but says to make sure you use Premium unleaded.Great stuff. Thx all. Will drain the tank and fill with premium unleaded. Quote Link to comment Share on other sites More sharing options...
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