Problems with Petsealed tanks and modern fuels - a warning

[alanaitch]

A couple of weeks ago, after two years work and a lot of cash spent, I finally finished building my beautiful BSA Rocket Gold Star replica (see pic).

She started first time, and sounded great.

Given that I hadn?t yet got her registered, all I could do was ride her up and down my (private) road to get the bugs ironed out.  So each day for the following week, you?d find me, chuffed to bits, riding to and fro, until one morning she wouldn?t start and was spitting back through the carb.  I also noticed that the compression was nowhere near what it was when I first started the engine.

I went through all the normal checks ? fuel, spark, plugs etc and everything was OK, but when I came to check the compression, there wasn?t any on the left-hand pot.

So, off with the rocker covers to make sure the valve clearances hadn?t closed, only to find that as I turned the engine over on the kick start, only the exhaust rockers moved!  The inlet rockers just stayed where they were!

At this point I decided to take the bike back to the guy who built most of the engine for me for him to diagnose the problem.

After taking the rocker box and head off, he found that both inlet valves were stuck fast in the guides, and that there was a hard, sticky residue on the top of the guides (see pic).

On top of that, both inlet pushrods were badly bent (see pic).

After some cogitating, he realised that the Petseal sealant that had been used when the petrol tank had been restored was being dissolved by the petrol ? now known as the ethanol problem.  So the fluid reaching the carbs was a very sticky solution of petrol and Petseal, which had built up on the valve stems and set hard.  Finally, enough had been deposited to cause the valves to stick, with one partly open, bending both pushrods.

In addition, the back of the inlet valve heads and the inlet ports were coated with the stuff and the carburettor completely gunged up.

After an awful lot of work including using strong solvents to remove the deposits from the valves and ports, reaming the guides to get rid of the stuff from there, stripping and cleaning the carb, fuel lines and filters, removing the rest of the Petseal from the tank, fitting 4 new pushrods, reassembling the head and putting everything back together again, the bike is now back to first class running order.

So my advice to anyone with a bike that has a tank that has previously been sealed with Petseal is DON?T START THE ENGINE until you?ve removed all of the Petseal from the tank.  Chris Williams at Autocycle Engineering can provide a solvent to remove it.  If you still need to seal the tank, Tank Care Products (http://www.tankcareproducts.co.uk) claim to have an ethanol resistant sealant, although I cannot verify that ? you?ll have to make your own mind up.

I hope that my experience will save many of you similar or even worse problems.

Alan

[alanp]

That's interesting for me since I bent a push rod and also had that junk on the back of the inlet valves - and my tank hasn't got any extra lining!!!
I'm going to check out my petrol pipes to see if its coming from a reaction to them. A friend with a 60's Honda kept having sticky throttle slides with gummy stuff building up on them. He currently is running with a fuel line filter to see if it collects anything.
Alan

[trickytree]

Im in the proccess of replacing the treated tank on my bobber with a untreated one. My tank wasnt done with petseal but the stuff imported by Wassell, so I doubt that it is a quality product.

Although the bike has been running great and I have done about 1500 miles on it I have had to strip the carbs due to sticking slides. I also noticed alot of build up on the inlet valve the other day (I could see it through the spark plug hole). I put it down to the bike burning oil as there was a bit of play in the valve guides when I reassembled the motor, but there simply wasnt enough cash in the pot to do owt about it at the time. Now you have got me thinking that perhaps it could well be a sealant problem as well??

I have heard that POR15 is also ethanol resistant also.

[muskrat]

A good warning to all Alan. A shame you found out the hard way.
 I used it to seal a oil tank. I didn't think of the blow by and fuel (methanol) mixing with the oil. Lucky I had a oil pressure guage fitted. Started up with 50lb but after 1 lap had nil. Start up again after a few minutes and 50lb again. One more lap, nil. A flap of the sealant was covering the oil feed line, but once the motor was stopped the flap would float back up.
Cheers

[chaz]

interesting story. wonder if its a recent batch process problem?
Ive used petseal for years in A65's, A7,T100,  just about to use it in another A7, and also customers Yamaha TDR250, Kawasaki Zephyr amongst others and never had a problem , may pay to ask if they have changed the make up of it.

[alanaitch]

Chaz,
It's not a problem with a specific batch of Petseal, It's due to the fact that the petrol companies are now adding ethanol to their fuel...and the ethanol dissolves the Petseal.  You can speak to Chris Williams at Autocycle Engineering or John Phelan at Sheffield British Motorcycles and they'll both tell you not to use it.  Shame I didn't speak to them earlier!!
Regds
Alan

[nagrod]

I have heard similar comments about Kreem, which is upsetting since I finally broke down Kreem coated the tank on my '60 A10 early this summer. Of course I didn't hear any bad press about it until after I coated it. Timing is everything! I haven't run the bike enough to have seen an engine problem (It's still a work in progress). Has anyone heard more about Kreem products and problems? And does any one know how it's removed if it needs to be?

Rick

[BSA_54A10]

Kreem is a different product and has a slightly different affect.
It will also dissolve in the muck we are sold as "petrol"
There are a lot more solvents in "fuel" other than ethanol.
A lot of petro chemical solvents have been banned from common use.
However they are still made as they are a by product of petrol refining .
The solution is to add them back into the "petrol" that we use.

Kreem when exposed to whatever brew we get in NSW Australia dissolves rapidly.
When enough has dissolved it turns what is in the tank into a non volatile liquid.
I had a bloke tearing his hair out with a bike that would not run, got got into the workshop for a thorough going over.
It would then start and run fine as it was being fed with fuel from a different tank on an overhead stand ( I use the same set up).
When reassembled with it's own tank and brand new fuel it would run fine, the client would take the bike home, big smile on his face.
Next week it would not run quite as well and a week latter it would not even start.
Back to the shop it went.
The mechanic finally tried a little test, he poured the fuel out of the dead bike into his own bike and that would not start either.
New fuel in the tank and all was well so the tank sat in his shop and he tried it every couple of days and sure as !!!! is brown within 4 to 8 weeks the fuel had go off to an extent that the bike would not start.
Cleaned the old fuel out of every thing and the cycle was repeated, worked fine for a couple of weeks then slowly went totally off.

So he sent the tank out for a strip and recoat with POR 15 and it is smiles all round, but this process hast taken the better part of 2 years to nail down and sent more than one bloke bald.

So yes tank sealants are now prime suspects for every problem that gets presented to me.
I am not trying to start a tank sealant panic but if you have sealant in your tank and are experiencing some unusual problems , have a good look at the fuel. Sorry to hear of your problems Alan but as you can see you are not alone and the fuel companies are to blame.
I wonder if any one has come to physical grief or even died when his fuel would no longer burn in his bike.

[brackenfel]

I'd heard about this at the local AJS & Matchless OC... None of my bikes have been sealed as far as I  can tell.

A quick search on Google and the first two links are :-

http://www.jawaczownersclub.co.uk/technical_advice13.htm

http://driversalliance.org.uk/press/view/348


Doesn't look too good.. I've always used "Super" unleaded in the Velo which happens to have a Mk1 Concentric fitted.. I think I'll go back to the standard "Premium" rubbish as it may just contain a bit less ethanol....

Cheers,
Adrian

[Desburnett]

Had virtually the same problem last week, see my earlier post "Stuck Valve" Originally thought I had over revved and caused valve spring bounce but after stripping down had exactly the same symptoms.
I believe the valve guides were originally cast iron which to a degree are self lubricating with free graphite. Not too keen on the phosphor bronze versions. One point I would check is the lack of a chamfer in the bore of the guide in the stem end. The guides that I was supplied with lacked any chamfer which prevents any oil build up in this area again reducing lube to the valve stem.

Des

[alanp]

Des, are you talking about a chamfer at the top of the guide (rocker box end) or bottom?
Alan

[dpaddock]

I "Kreem"-ed my Goldie tank (steel) in 2000 and the coating is still firm and sound.  I know of one other tank that was Kreem-ed; it's a fiberglass tank and the coating has gone soft and pulled away.

I coated my steel Spitfire tank earlier this year with the Caswell product, and it's fine so far.

One thing for sure: prepare the surface exactly per the manufacturer's instructions and proportion and mix the ingredients precisely.

David

[Desburnett]

Alanp. Chamfer was missing in top of guide rockerbox end.
Des

[gold33]

On the fuel front,
Had a chat to a disgruntled workshop Manager on Saturday, he filled a just finished bike with 98oct fuel from a local Mobil station, tuned the bike and felt pretty good about himself, the next day the bike took quite an effort to start, the day after it wouldn't start at all...
After a couple of weeks of playing on and off he discovered a sticky residue in the carby (tank not lined), long story short the fuel was dissolving the fuel lines! It also dissolved the plastic cover off his feeler gauges after he soaked them in the fuel to clean them up.

[taroha10]

Evening all,Thanyou Alanaitch for your warning .
Now i'm in a quandary.I did the tank of my M20 with Petseal a few years back.I have not had any problems so far but obviously am concerned.I am usually a bit wary of those sort of products but it has been excellent and cured the leak I had.It seems that the modern fuel is causing problems to many who have used these products.I know no-one can tell me exactly what to do but has anyone found they are not having problems.Also has anyone flushed the tank with solvent and been fairly sure the sealent has all come out?Other than that it is maybe unweld the tank and shotblast it off.The good thing is that the bike is laid up needing a fork overhaul and I do have a very rusty but spare tank.And the super Rocket dosn't seem to have any coating in it's tank.Cheers to you all.Mark.