Valve Additive for Unleaded Fuel

[Rick F]

Just want ask for some advice re fuel additives for a 750GT.

As I understand it, we are all adding an additive to our fuel for the older Ducks, to protect the valves (?)

I am following the instructions on the bottle 1ml/litre (1.5fl.oz/10 gallons)

My questions are:

1) can you add too much? (what would be an accepted tolerance?)

2) if NOT added, how long before damage is done?

Living in a regional area, it may not always be available & I want to know how diligent I need to be about carrying some with me.

There is a local bevel/desmo specialist, and he suggests just to "throw a bit in every 3 or 4 tankfuls"

Thanks
Rick

[DesmoDog]

Just want ask for some advice re fuel additives for a 750GT.

As I understand it, we are all adding an additive to our fuel for the older Ducks, to protect the valves (?)

I'm not. The heads have seats installed in them that can handle unleaded gas just fine from what I can tell. Not that I ride the GT enough for valve recession to be a problem...

[Nick]

I've never added lead to my unleaded fuel, I ride the @#$ out my stable of British and Italian classic bikes and I've never had any valve-related problems, the valves seldom need adjusting and the bikes run fine. I think its all just a lot of worry about nothing. (My 45-year-old car also runs fine on unleaded!)

[Laurence]

I ran 2 identical japanese motorcycles for 100 000 km each on the same maintainence program, one on leaded and one on unleaded fuel
The manual recomended leaded fuel only.
I did a valve job on the one that ran leaded at 60k and nothing to the one i ran on unleaded..
Since that experiment ive been of the opinion that the fuel additive gag is the same as the Y2K gag that was going to destroy all our computers and end the world as we know it..

[linblad]

get ya heads done so it takes unleaded contact justin at protwin in perth 0412924308 he used to work at veetwo and since they no longer do engine work as they goy bought out he went on his own, had mine done 4 years ago fantastic stick any unleaded fuel in her no dramas ! good luck linblad.

[78SS]

My SS runs like a 2 stroke on unleaded, fouls plugs alot, so I have to buy expensive race gas to run it. I have had it tuned by professional mechanics who I trust. Anyone else have this problem or is it just me?

[78SS]

Hi Peter, I am running standard plugs and they run fine on leaded gas, I have found unleaded petrol does not fully combust in any engine leaving a oily coating in the tail pipe.

[Gomi]

Do you have stock pistons or High Compression ones?
HC pistons often require a greater octane fuel... maybe is this the reason.

[78SS]

As far as I know its standard compression, it did run fine on leaded gas with the same octane rating. Might need hotter plugs to burn off residue from combustion, as I have mentioned I do not think unleaded combusts properly like leaded gas as there is a oily residue left in tail pipe.

[Rick F]

So gents,
it got a little like a political forum, skirting the question but never really answering it!

It sounds to me like there are a lot of opinions out there about this.

I am a little uninformed, (a builder, not a mechanic or engineer), but if someone in the profession that I trust says to throw a bit in the tank every now and then, I do....I buy the bottle and follow the instructions, and hope that it cant hurt! Pirsig would cringe!

Yes I am running high octane unleaded anyway, people I have known that do know what they are talking about say that the standard Unleaded here in OZ is dog doodie, so premium is the go....but for every thing except the cars. I use premium in the ride-on mower, the outboard motor, the brushcutter.
and it does seem to improve the reliability.....no major failures or carb rebuilds etc.

So when I 1st got the bike back in 1986, (my 3rd GT) it had a rebuilt unstarted motor, with Sport pistons and valves. Apparently. It was a long time ago.

What way are the valves different? would they cope with unleaded better than standard valves? (premium unleaded)

Rick

[MartinMille BANNED]

Hi Rick
I use Valvemaster and have for years ,you sure notice the difference when you run out of the stuff , the Mille starts to ping its heads off and has lack of power add valvemaster and within 5 min's she purr's again
get some and try it

[Rick F]

Hi Martin,
I have been using the valvemaster since I put the bike back on the road.

I am not too far from Arthur at Byron Bay and it was he that prompted my questions....ie just thro a bit in every few tankfuls.

As I say, I am religous with it and it seems to make the ride-on go a bit better as well!

Whereabouts are you?

Rick

[MartinMille BANNED]

Rick
just thro a bit in every few tankfuls...is an old mechanics term I used to say that as well, what he meant by that was ,the bike will run on the std fuel but since there is no more lead in the fuel you have no upper cylinder lubrication and your valves run hotter etc etc end result burnt valves or worse, better to add some then none at all adding more will do no harm same goes to engine fuel de-carbonizers

I'll driving past your way in two weeks but no on the bike
I'm a Wisemans Ferry on the Hawksburry

[Rick F]

Hi Martin,
the beautiful hawkesbury, fished it many a time....used to run the marina at Berowra Waters

Mate by all means, if you are passing drop by for a cuppa or a beer or something.
We are a little out of the way at Crystal Creek, but you could shoot up the back way into nerang if you are going further.

I have other problems with the bike now, I dont know whether you have seen my post re the cracked fork leg, but I am trying to sort that out so I can go for a ride.

Rick

[Rick F]

Hi Martin,
I just checked that post of mine re the forks,

Thanks for the advice. The treasurer is adjusting the budget as wee speak, to allow for a new pair of fork legs for her christmas pressy!
Rick