Glass fibre petrol tanks and problems with Ethanol in pump fuel.

[John Wakefield]

The following posting has been up on the RC forum, it effects Greeves bikes with glass fibre tanks. Looks like its the ethanol based petrol that is causing the resin to melt. What do members think

My recently acquired AJS is causing me angst again. It has done 200 miles since being rebuilt, not by me. It has a new fibreglass petrol tank. Today the throttle became sticky. On taking the carb off to check it I found a sticky residue in it. Peering further into the depths revealed that the inlet tract is coated in the same sticky residue. After a short head scratching I opened the tank and felt the inside to find the tank inside is also coated in this same sticky residue.
I presume the petrol has reacted with the tank. The bike builder isn't interested, saying he got it from a bloke who sells them at an auto jumble and as it's new it should be OK. If not try some pet-seal.
I'm more concerned about what may happen to the top end e.g. sticking valves or rings - the residue is very sticky, as few other sticky things are.
Anyone else had a similar issue? And what's the advice - bin it?

Johnny H

[Bearingman]

The following posting has been up on the RC forum, it effects Greeves bikes with glass fibre tanks. Looks like its the ethanol based petrol that is causing the resin to melt. What do members think

My recently acquired AJS is causing me angst again. It has done 200 miles since being rebuilt, not by me. It has a new fibreglass petrol tank. Today the throttle became sticky. On taking the carb off to check it I found a sticky residue in it. Peering further into the depths revealed that the inlet tract is coated in the same sticky residue. After a short head scratching I opened the tank and felt the inside to find the tank inside is also coated in this same sticky residue.
I presume the petrol has reacted with the tank. The bike builder isn't interested, saying he got it from a bloke who sells them at an auto jumble and as it's new it should be OK. If not try some pet-seal.
I'm more concerned about what may happen to the top end e.g. sticking valves or rings - the residue is very sticky, as few other sticky things are.
Anyone else had a similar issue? And what's the advice - bin it?

Johnny H

We have had this problem for years in the state of California. Years ago the state added Gasohol to fuel our cars and trucks.

I use leaded 112 octane race gas in all my Greeves with glass fiber tanks, not only does it eliminate or at least slow down the resin break down, but the engines run cooler with no detonating problems, jetting is more consistent and plug readings as well.

I built an MX3 for pre-65 races and the owner used pump gas, the bike stopped running with the bowl being filled with a gooey substance, the pilot jet being plugged and as you would expect, the motor would not re-fire.

I hope this helps.

Regards,

Kenny Sykes
USA

[John Wakefield]

Thanks Kenny
Problem over here in UK is that of road bikes, the Greeves 25DD Essex has fibreglass tank as does the trials TGS Anglian which we ride on the road as well. all of which have to use pump fuel. Cant get 112 octane hear unless you have access to avgas. Luckily my bike a 25DC East Coaster has a steel tank which came after the 25 DD Essex. I think that as the EC was destined as an Export model to the USA it was a legal requirement for road going motorcycles to have a metal tank. Maybe this is still so.

[stormer254]

Apparently or so I have been told, it is the composition of modern pump fuel, Bioethanol is added and it reacts badly with fibreglass tanks, just like methanol, the only answer that I am aware of is draining your tank after every use which is what I do with my Challengers, Cotton, Stormers and Cheetah. i also add an octane booster and it would be a shame to let it evaporate out of a vented tank.

[Bearingman]

Thanks Kenny
Problem over here in UK is that of road bikes, the Greeves 25DD Essex has fibreglass tank as does the trials TGS Anglian which we ride on the road as well. all of which have to use pump fuel. Cant get 112 octane hear unless you have access to avgas. Luckily my bike a 25DC East Coaster has a steel tank which came after the 25 DD Essex. I think that as the EC was destined as an Export model to the USA it was a legal requirement for road going motorcycles to have a metal tank. Maybe this is still so.

John,

I had forgotten that some road bikes had fiberglass tanks, maybe this is the reason why the first Ranger imported to Nicholson had a glass tank and then changed over to steel to certify for USA road use??

BTW John, my wife Kathy has in her possession an EC type road bike but painted blue, it is part of the lot brought to the west coast. It is in storage and I'll look up the frame number for you when I can get to it.

Kenny

[MikeTizard]

John,

I've had the same on my Challenger. The tank is 45 years old and i've tried petseal etc - no joy. The side of the tank seems very thin and weak and deflects under pressure. The sticky residue is in the carb and the inlet tract of the engine but it does however come off with fresh pretol on a rag and some vigorous rubbing!! It is a real pain, and I really do not trust it at all.

I've ordered a new tank from Roger Ennis who advertises in LL. Chatting to him about the probelm he informs me that a new chemical is mixed in with the fibre glass resin on the new tanks that he builds and they will not be affected by the modern fuels. He has a wide range of moulds and can build new tanks for most bikes. If in doubt, I would recommend asking him.

Incidentally I put a new tank on my Anglain about 10 years ago. It has been fine with no signs of deterioaration at all, and this fits with what Roger told me. Some of the tanks are fine, and others just seem ro react with the fuel!!

[Brian Thompson]

Following on from John's original post, I've been doing some digging on the internet and have discovered that this is a huge issue, with lots of info and 'chatter' on forums and websites everywhere! The issue is not just confined to bikes as it also affects boat users and, more worringly, light aircraft...(i.e.Cessnas)

In addition, there are some concerns over similar problems caused by fuel additives like stabilisers and octane boosters as well....

What I did was type 'effects of ethanol in fibreglass petrol tanks' and then 'effects of ethanol in fibreglass motorcycle petrol tanks', and as mentioned a heck of a lot of info comes up!

To save everyone time, the best 'summaries' I managed to find of the current situation (from our point of view) can be found by typing the following into your search bar for further info;

1.) www.fbhvc.co.uk (to which the GRA is affiliated, of course.)

Once on the site homepage, search for FBHVC Newsletter#5 'Forthcoming Changes in Fuels'.

The FBHVC info has been covered in 'Leading Link' of course (thanks to Mike Eady), but it's worth having a look anyway for updates etc.

2.) trials central fibreglass fuel tanks and ethanol

This will take you to the relevant page on their (excellent) forum with lots of useful info and links.

One of the problems seems to be that the amount of ethanol present in pump fuels varies. EN10 is the 'standard' fuel, and should contain 5-10% ethanol, which apparently shouldn't give problems (and yet does!) Anything from 11% and upwards will give problems with some materials however! Fibreglass reinforced polyester and fibreglass reinforced epoxy resin are the worst affected, and apparently fibreglass reinforced plastic (which plastic though?!!!) is ok....! This bears out Mike Tizard's helpful post and the new materials Roger Ennis is now using in his products.

Some metal tank sealants are also prone to attack, with some apparently being better than others. The 'best' reported results seem to be with caswell products (click on this link and have a look at http://www.caswelleurope.co.uk/gastank.htm) although POR15 seems to be not so good (click on this link http://www.frost.co.uk/ and search for fuel tank sealer.) I suspect this is being further confused by exactly which brand of fuel is being used etc.

Another option (albeit expensive @ £399!) is to fit an alloy tank of course. The type that used to be marketed by Surrey Cycles are now available again and should fit Anglians etc. The contact is (note, this is NOT Surrey Cycles!) n.lewis452@btinternet.com or telephone 01483 275170. Also check out www.holtworks.co.uk who produce two styles for Greeves (wideline and slimline) and are a little cheaper (thanks for the info Paul!) As far as tanks suitable for Essex models it might be worth checking out www.thetankshop.com and having something custom made perhaps, copied as per original. The website shows some of their amazing work and the prices are similar for 'stock' items, and go from about £400 upwards-again not exactly cheap I know! John Williams is the craftsman to ask and prefers to be contacted for enquiries by post or telephone (01387 740259.)

I remember years ago the problems with safety (and ensuing legislation) that came up when plastic fuel tanks started to appear on bikes, with the fears of potential splitting in a prang on the road, coupled with the ensuing blaze of sparks that would be present during the 'earth/sky/earth/sky' phase (quote Kenny Roberts!).....horrible thought though isn't it..... Toast, anyone.....?!!! A mate of mine told me at the time that a switched-on copper actually 'tested' the tank on his bike with a magnet that he produced from his pocket!

On a related point, I'm unsure as to the current legislation as regards the use of plastic and fibreglass tanks on road bikes, but wouldn't be surprised to find that it's yet another 'grey area' as regards classic bikes etc...Current manufacturers are probably ok (modern materials used and 'type approved' no doubt, a la KTM, Ducati etc.) but as far as fibreglass goes I personally don't know....Does anyone else have this info? I know they are sold for use on 'new' Enfields (Continental GT type, etc) but that they too have been having the same problems with seam failures....I guess in the event of a 'pull' a 'rectification notice' might be what you'd get, but it would be worry if it turned out that your insurance was invalid in the event of an RTA, heaven forbid...especially after all that hassle finding and applying a sealant that's ethanol proof!

I'm just glad that the steel tank on my TCS looks pretty sound, with no sealant or rust inside, and hopefully not too many dings under the silver paint-I hope to get it re-chromed (satin) one day! Thing is, it'll probably cost about the same to get it done as a custom alloy tank I reckon....! Oh well etc....!

Anyway chaps, hope this helps 'fuel the debate' a bit....(sorry!)

Anyone else got any tips or experiences to share?

Brian.

[stormer254]

Greeves competition tanks are so easy to take of just drain them properly after use.

[John Wakefield]

Not an easy option on road bikes

[stormer254]

Cheaper than buying a new tank though!

[Peter Rotherham]

Glass Fibre Petrol Tanks.

The 'safety' argument has raged on since these were invented. I myself saw a RE GT 250 that had burst into flames after the red racing tank split following a fatal collision with a wall. But the question is now, what are they putting into the 'lead free' petrol?
In the old machinery world, most things are powered by JAP or Villiers stationary engines. The carbs on these often sit for the winter months with a residue of fuel in them. Before, the fuel would go brown and smelly, but could be cleaned out with fresh petrol. Since the mid 90's however, the fuel seems to act as an electrolyte between Bronze and alloy, resulting in main/pilot jets becoming a horrible green mush. Lawnmowers are particularly prone to attack, and I'm getting several anguished owners asking me why their mowers won't run after being carefully stored over winter. £95 for a new carb doesn't go down well!
I know that there are different mixes for winter & summer, and that 'aromatics' are included to improve octane ratings, but this resin problem is a new one on me......

Peter Rotherham.

[merlin]

Why not drain the carb or run until empty?

[Brian Thompson]

That's my routine too Merlin; switch the fuel off and leave it running till it stalls. Must admit it does seem to work well, and I don't tend to have problems with a gummed carb even when the bike has been stood for a while.

Mind you, I tend to use Shell V-Power pump fuel in my TCS which apparently (or so I've been informed) does not contain ethanol, as I've mentioned in a previous post, so perhaps this helps too?

Brian.

[IanCordes]

This does raise the question of the efficacy of tank sealants. I recently 'sealed' my slightly leaky wideline Dommie tank with 'Petseal'; following the instructions to the letter; allowing recommended curing time etc. After a very short while, the leak came back. The supplier of the sealant professed to be baffled by this, but, for a reasonable charge, sent me some resin solvent, with which to remove the ineffective sealant. The solvent is, of course, paint stripper -Methylene Chloride, containing methanol. As mentioned earlier in this thread, ethanol, like methanol, dissolves fiberglass tanks. So, we have gone full circle. The ingredient in petrol which causes problems with fibreglass tanks, also dissolves tank sealant.

Not much good, either of them really, are they?

Cheers
Ian

[Peter Rotherham]

Fibreglass Fuel Tanks.

For an exhaustive discussion on the problems of modern fuels destroying Fibreglass fuel tanks, see the Norton Owner's Club magazine, "Roadholder" for June 2010.