Page 2 of 2

Re: nc30 valve stem seals

Posted: Wed Mar 18, 2015 7:00 am
by yamahaha
Aye its deffo the stem seals gone on the vfr you could see it sat around the valves when the carbs were off ..... I also got a cotton bud to inspect the liquid and it was motuls finest

Re: nc30 valve stem seals

Posted: Wed Mar 18, 2015 7:09 am
by skinnydog0_0
:(
Thats not a nice thing to find.

Re: nc30 valve stem seals

Posted: Wed Mar 18, 2015 5:42 pm
by richyrd5
so is it best to use normal unleaded from the pump or super?dont wanna be screwing me fuel lines/rubbers etc.

Re: nc30 valve stem seals

Posted: Wed Mar 18, 2015 7:05 pm
by yamahaha
http://www.mag-uk.org/en/campaignsdetail/a6973 just type in ethanol in petrol on google ... There is some interesting reading on there about it .... My facts earlier on were not 100% right, at the moment they can only legally add 5% ethanol in normal u/l but even this amount can cause damage. Ethanol loves water as well, which for obvious reasons is not good for ageing steel fuel tanks and can melt / distort plastic tanks on older machines.... I recently had to replace my dynojet needles in my carbs as the fuel had eaten them, and I read something this morning which said the fuel companies only add the ethanol at the last possible minute as it causes corrosion in the tankers and also rots the delivery hoses ..... I

Re: nc30 valve stem seals

Posted: Thu Mar 19, 2015 2:05 pm
by richyrd5
wow.thanks for link..bastards aint they..

Re: nc30 valve stem seals

Posted: Thu Mar 19, 2015 4:10 pm
by Neosophist
yamahaha wrote:http://www.mag-uk.org/en/campaignsdetail/a6973 just type in ethanol in petrol on google ... There is some interesting reading on there about it .... My facts earlier on were not 100% right, at the moment they can only legally add 5% ethanol in normal u/l but even this amount can cause damage. Ethanol loves water as well, which for obvious reasons is not good for ageing steel fuel tanks and can melt / distort plastic tanks on older machines.... I recently had to replace my dynojet needles in my carbs as the fuel had eaten them, and I read something this morning which said the fuel companies only add the ethanol at the last possible minute as it causes corrosion in the tankers and also rots the delivery hoses ..... I
Fuel will NOT eat carb needles. Carb needles are metal, same as the tank and the carbs and the engine, if by any chance you did have some kind of liquid that could eat carb needles it would more than likely eat the tank and carbs way before the needles as the contact time is much longer.

Ethanol does attract water so it isn't great for laying a bike up with.

VFRS are pretty ethanol proof, even upto 10%, you can get aftermarket viton rubber gasket sets for the carbs for pennies now from out supplier on here.

Very old cars and bikes which have much more rubbery parts can be eaten by ethanol as it is a very good solvent / cleaner.

Not sure about the tankers but most of the delivery trucks carry additive free gasoline and it is computerised mixed on dispensing, that way one giant truck and deliver super unleaded and unleaded from the same tanker.

Unless you are regulalry using E10 or higher then I wouldnt worry too much about Ethanal.

As for what fuel to use it doesnt matter, as long as the octane rating is above 91 the bike should run fine, anything higher is just wasted (all it means is you can compress the fuel more before it explodes due to heat and pressure instead of spark plug, since the engines compression is fixed it is of no consequence).

Super unleaded is often justified by mfgs as having superior cleaning properites but in realitty most modern engines burn so clean that it isnt really needed.

I've taken apart bike engines that have covered nealry 100,000 miles on regular fuel and have been clean as new inside.

Re: nc30 valve stem seals

Posted: Thu Mar 19, 2015 7:17 pm
by yamahaha
Well I must be imagining things then bud eh ? Ps I always thought carb needles were made of chocolate

Re: nc30 valve stem seals

Posted: Fri Mar 20, 2015 2:30 am
by GeeTee
skinnydog0_0 wrote:Yer they are crap. I have just got a set of Denso iridium plugs, they are supposed to be better- not tried them yet but others seem to rate them. Same sort of price as the ER9's
I used the denso iridium's in my trackbike last year

Seemed to start and run better than with normal ngk plugs

Re: nc30 valve stem seals

Posted: Sun Mar 22, 2015 1:58 pm
by Neosophist
GeeTee wrote:
skinnydog0_0 wrote:Yer they are crap. I have just got a set of Denso iridium plugs, they are supposed to be better- not tried them yet but others seem to rate them. Same sort of price as the ER9's
I used the denso iridium's in my trackbike last year

Seemed to start and run better than with normal ngk plugs
I put denso iridiums in my 30 and they were there well over 10k miles without issue.

as for the running didnt notice anything, service life is longer though.

As for carb needles, never come across any bike that eats carb needles. the only time i saw a needle faliure was a set of custom made alu needles on a zxr race bike that had stainless steel clips on them and the vibrations cuased the clips to eat the needles away.

My 1950s bikes still have original needles in them..