classic motorcycle forum

Motorcycle Discussions => British Bikes => Topic started by: GusSmith on September 14, 2005, 04:40:01 AM

Title: UNLEADED PETROL
Post by: GusSmith on September 14, 2005, 04:40:01 AM

This may be a naive question, but here goes:
I am considering purchasing an older (50s or early 60s) motorcycle. My short list comprises MSS, Viper, Venom, G80, G9 or G11.
My question relates to the use (or not) of unleaded fuel in these machines. Can anyone advise, please?

Title: Re: UNLEADED PETROL
Post by: L.A.B. on September 14, 2005, 07:07:34 PM

A lot of owners have run older bikes on unleaded petrol now for quite some time with little or no problems (myself included).
You could use a fuel additive (I use Castrol Valvemaster Plus) or you could get the valve seats changed if you intend to do a high mileage but maybe just keeping an eye on valve clearances will be enough.

Unless you live near a Bayford filling station that still sells leaded fuel then you haven't really got much choice but to use unleaded fuel now that LRP has mostly been phased out.
http://www.leadedpetrol.co.uk/  

Title: Re: UNLEADED PETROL
Post by: boatman on November 30, 2005, 03:30:14 PM

The Vincent Owner Club have a very good technical write up by Jaqueline Bickerstaff on Leaded Petrol. Go to:
http://www.voc.uk.com/archives/html/petrol.html

Title: Re: UNLEADED PETROL
Post by: Mr.Turbo on December 28, 2005, 05:37:46 AM

As stated above. It's an issue with the valve seats. Newer engines that run on unleaded fuel have a harden seat. In older engines the lead in the fuel harden the seats over time. You should replace the seats with harden ones. Or use a fuel additive.