Pink coloured petrol != good petrol

The 3 1/2 forum
Post Reply
julianharty
Posts: 478
Joined: 15 May 2016 16:34
Location: High Wycombe
Location: High Wycombe Area (Bucks)

Pink coloured petrol != good petrol

Post by julianharty »

The cute 3 1/2 sport I bought had had the petrol tank 'treated'. The seller couldn't remember what product he'd used.

Once I'd started riding the bike I noticed all sorts of running problems, possibly related to fuelling and/or jetting. I had a receipt for most of the jets being replaced. However Rob at NLM and reading various posts in this forum encouraged me to buy some 45 pilots, and some 260 U atomisers (If I remember correctly) as the bike has a 2 into 1 exhaust. When I removed the bottom of the carbs I discovered the fuel was bright pink, the colour of the supposed tank treatment. I'm using the higher grade Shell petrol and have ridden the bike less than 100 miles so far.

Anyway I cleaned up the carbs a bit and fitted the replacement jets. So far, so good, the bike rides much better. I'll keep riding it (in between other repairs) and hopefully whatever's left of the pink gunk will soon be used up. Then I can return to sorting out the finer details of the jetting :)

If anyone's got some recommendations for what might be in the tank and what to do with it please tell me. For now I'm planning to only use the higher grade petrol (no ethanol, I hope) and to ride the bike more a month than it was ridden per year for the last decade or so.
AntietamClassicCycle
Posts: 187
Joined: 15 Oct 2012 15:03
Location: Rohrersville, MD, US
Location: Rohrersville, MD, USA
Contact:

Re: Pink coloured petrol != good petrol

Post by AntietamClassicCycle »

There is/was a tank sealer called "Red Kote" sold here in the US that the coloring leached out of as you describe. That was a few years ago and supposedly they've reformulated it so that doesn't happen now. But, I still don't trust it and will only use the one that I do - Caswell Epoxy Gas Tank Sealer. Even then, I only use a sealer as a "last resort" on seriously rusted or leaking tanks.
julianharty
Posts: 478
Joined: 15 May 2016 16:34
Location: High Wycombe
Location: High Wycombe Area (Bucks)

Re: Pink coloured petrol != good petrol

Post by julianharty »

Thanks for the info about what the ghastly red coating might be & your perspective on it. My tank isn't leaking, the RH fuel tap does so happily most of the time. I've bought a new one to replace it and will do when I've ridden the bike enough to use more of the fuel in the tank.

BTW: This bike's determined to provide a rich, detailed and memorable experience as I'll describe in other posts... I'm still happy I bought it though, it's 39 years old, and will ride well once the gremlins have been addressed. It's pretty good to ride already.
julianharty
Posts: 478
Joined: 15 May 2016 16:34
Location: High Wycombe
Location: High Wycombe Area (Bucks)

Re: Pink coloured petrol != good petrol

Post by julianharty »

More news on the tank and fuel.

As I've mentioned in another post, I've removed the fuel tank so I can sort out the underside. I discovered someone had applied a cloth-based patch to an area on the RH that'd normally have a metal tang to help hold a chrome edging to the bottom edge of the tank. While the patch didn't seem to be leaking there was some evidence the paint on the outside edge of the tank nearby had been damaged, perhaps by petrol. I've used JB-Weld metal epoxy to secure the edge of the patch, then thoroughly cleaned the underside of the tank, treated it to 'remove' the rust which seemed partially successful, then used a strong wire-brush everywhere except around the patch. I've now painted the underside of the tank with 3 coats of Zinc 182 primer in preparation for further protective paint. I've also primed the edges of the tank and will paint them first black (to blend with the dark green someone's painted it) and will then touch up the green until I repaint the bike, probably in the original red (as indicated by the old paint on the tank's underside).

I'm tempted to weld an infill when I repaint the tank, panels and mudguards (they're all the same dark green). I've welded tanks successfully before and can then address any weaknesses without needing whatever the liquid liner is (I hope).

I'm curious what you've done (if anything) to resurrect/repair Morini petrol tanks. Suggestions and experiences are welcome. I'll post updates on the forum too.
Post Reply