Curvy won't idle without choke, won't do mid throttle, will rev

[Red Herring]

Also worth noting is that Ethanol isn't particularly friendly to your bike, especially when you leave it in there for protracted periods of time. Some brands of Super Unleaded used to be Ethanol free but I think they all pretty much have 5% now, although maybe Shell and BP Ultimate might still be holding out (I gave up trying to avoid Ethanol eventually and now just use additives as has been discussed).

[SV650rules]

Originally Posted by Red Herring

Also worth noting is that Ethanol isn't particularly friendly to your bike, especially when you leave it in there for protracted periods of time. Some brands of Super Unleaded used to be Ethanol free but I think they all pretty much have 5% now, although maybe Shell and BP Ultimate might still be holding out (I gave up trying to avoid Ethanol eventually and now just use additives as has been discussed).

+1

Ethanol attracts water which will cause corrosion in fuel systems not specifically designed to handle it.

https://auto.howstuffworks.com/fuel-...age-engine.htm

[Bibio]

Originally Posted by SV650rules

+1

Ethanol attracts water which will cause corrosion in fuel systems not specifically designed to handle it.

yes alcohol does attract water like brake fluid (hygroscopic) but it actually helps emulsify the water that usually sits in the bottom of the tank so is actually helping to stop the tank rust.

the big problem facing carbed bikes that use fuel with alcohol is the lack of lubrication in the float bowl chamber resulting in sticky floats and shut off needles/valves resulting in the carbs flooding. adding a tiny bit (a few ml per tank) of say 2t or indeed any oil to the tank will help in stopping the above (do not add to FI bikes). the good news is that the alcohol helps with winter carb freezing.

alcohol will not rot rubber or plastic components any quicker or slower than petrol.

the gel like substance that is left in the carbs after prolonged periods is emulsified petrol as the carbs are open to the atmosphere.

there is no need to put any fuel additives in modern FI bikes.

modern fuels are designed with additives to help keep the combustion chamber and associated components clean so there is no need to put any more in such as redex, your just throwing your money away.

[SV650rules]

Originally Posted by Bibio

modern fuels are designed with additives to help keep the combustion chamber and associated components clean so there is no need to put any more in such as redex, your just throwing your money away.

We will just have to disagree on that, after I started using a bit of redex every so often and over winter, I have never had a problem with fuel system on bikes, and still glug a bit in cars every so often and never had any fuel system problem with them either. Makers will put minimum additives they can in fuel, and if you buy Ultimate or such 97RON it actually costs you more than redex taken over a period. I have seen Redex bring engines back from the dead, no-one ever saw J3sus do the same, but millions still believe in him LOL

We are not talking about a lot of money here, a quick trip to Halfords or local motor shop (or even Asda etc.) - it either cures it or it won't, but it won't cure itself by talking about it and recommending stripping carbs down ultrasonic cleaning etc.

[R1ffR4ff]

I've been doing a bit of reading up and apparently Supermarket chains don't put as many additives in the fuel as the Branded stations.Also it's not commonly known but Oil companies change the fuel mix for Winter and Summer.

Since using RedX in my Carby bike the last two days longish ride-outs out my Reserve light didn't even come on at 150 miles.Which for a sit-up-and-beg is cool for me and as good if not better than my old Honda CX500s

There's a lot of decent reviews around on Fuel Injection additives as well,

https://www.amazon.com/Liqui-Moly-20...ustomerReviews

As these things have done me no harm I think even if I had an FI Motorcycle I'd give them one big glug and then see how they went.For me it's fuel stabilization effect I want as well as my bikes can get left for some periods of time and I've had issues before with,"Stale Fuel"

[Red Herring]

Originally Posted by Bibio

there is no need to put any fuel additives in modern FI bikes.

modern fuels are designed with additives to help keep the combustion chamber and associated components clean so there is no need to put any more in such as redex, your just throwing your money away.

Speaking as someone who owns several bikes that only get run once or twice a year I'm going to have to disagree with you on that one. I'm not privy to the technical reasoning behind it but I sure know from experience that if I leave some of them with old untreated fuel in the fuel system I'm going to have issues when I try and start them.

Edit: in fairness Bibio I think there are two issues here, one is do we need to add anything to modern fuels to improve performance or maintain the engine, in which case I'm inclined to agree with you, the other is do we need to add anything to modern fuel to stop it going stale and potentially causing issues, and my view is you do.

[SV650rules]

I always refer to petrol or diesel as Dinosaur Juice because they are not as clean as they look and when they evaporate they leave gummy lacquer residue behind, both inside carbs and on injector nozzles - this is the remains of old plants and trees, dead sabre toothed tigers, mammoths etc. in fact whatever was there to decay and turn into crude oil.

Petrol that is left untreated in bikes (or even stored in cans for a while) can lose its more volatile compounds which are the ones that explode most easily, so this makes engine harder to start, but the same evaporation leaves residues behind that can block things up and stick things together inside the fuel system, neither of which are helpful.

[R1ffR4ff]

[DuncanC]

Its not the dinosaur juice that evaporates it is the additives that are used instead of lead. The lovely carcinogenic things like toluene and benzene. These are very volatile and evaporate out of the fuel which is why old petrol stops your bike from starting. If you could get the bike warm the dinosaur juice would start to evaporate and everything would be fine.

[SV650rules]

Originally Posted by DuncanC

Its not the dinosaur juice that evaporates it is the additives that are used instead of lead. The lovely carcinogenic things like toluene and benzene. These are very volatile and evaporate out of the fuel which is why old petrol stops your bike from starting. If you could get the bike warm the dinosaur juice would start to evaporate and everything would be fine.

Lead tetraethyl in petrol was used to improve octane rating (ie make it harder to ignite petrol in cylinder and reduce compression induced self-ignition allowing higher compression ratios to be used improving efficiency of engines). That is why other octane improvers you mention are are used, if they evaporate it would lower the octane rating and make fuel easier to ignite.

Leaded petrol used to degrade when stored as well, was this caused by the lead evaporating ?

The availability of 100 octane plus fuel from USA was one of the reasons our aircraft outperformed the Jerries later in WW2, allowing higher boost pressures to be used in our aircraft engines (and other engines like MTB's as well).