Leaded Fuel Question

pirata · Derestricted Danger Joined: 13 Dec 2005 Karma :

Hi

I've just joined up. Some background info. I'm 27, from South Africa and ride a Z750 daily and have a TZR250 (3MA) for messing about.
In January I won't be able to get Leaded fuel at the pumps. Will unleaded be a problem for the TZR?

kawakid · World Chat Champion Joined: 15 Mar 2005 Karma :

Do you mean real leaded? or the lead sub stitute?

When leaded was band here, they still did a 4 star, but it was called LRP (Lead Replacement Petrol).

Not sure about your bike, but you can get additives to add to unleaded if need be.
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pirata · Derestricted Danger Joined: 13 Dec 2005 Karma :

Real leaded! We a bit behind here to the rest of the world.
There is talk about us being able to purchase Lead additives. Are those OK? Do I need to make any adjustments to the bike or is it just thrown into the tank with the rest of the fuel?

doggone · World Chat Champion Joined: 20 May 2004 Karma :

All Jap bikes since about 1980 should be fine with unleaded.

pirata · Derestricted Danger Joined: 13 Dec 2005 Karma :

Thanks very much!!
Will I notice a performance / consumption difference?

Now all I need is for the accelerator cables to arvie so I can start riding her again!!

stinkwheel · Bovine Proctologist Joined: 12 Jul 2004 Karma :

The lead is there to lubricate the valve seats. 2-strokes don't have valves so no worries there.

Unleaded fuel has been mandatory in Japan since at least 1978 but a great many of their bikes made before that had 'lead free' hardened valve seats. So unless your Z750 is one of the very first of the twin cylinder monstrosities they produced in the 70's (and I would be very surprised if there are any still on the road). No worries.

One minor point is that in the UK at least, the unleaded fuel is several octane units lower than the leaded was. If one of your engines is in a very high state of tune (I am thinking of the TZR here), you might find the engine starts 'pinking' (predetonating). If this is a problem, you might need to add an octane booster or find somewhere that sells higher octane 'super' unleaded.
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pirata · Derestricted Danger Joined: 13 Dec 2005 Karma :

That was my thinking Stinkwheel. Our leaded and leaded fuels are the same octane here to it should be ok. The Z750 is the new one so I have no issues there.
Thanks bud!!

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

As Stinkwheel says, it is a 2 stroke so it could not care less about the lead.

UK unleaded is 95 RON while UK leaded (4*) was 97 RON, which is why cars sold set up to run on 4* often needed the ignition timing retarded to cope with unleaded without pinking (and the change in ignition timing reduced performance).

With the TZR I am not sure what fuel it was designed to run on. A lot of Japanese made bikes have quite low octane requirements.

All the best

Keith
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