Honda Twins banner
1 - 7 of 7 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter · #1 ·
My CM400e has fuel tank troubles. Overall, the tank is in good shape, but it wears the marks of 37 years of less than an easy life. I plan to address most of it's problems this weekend. Advice is needed.

1. The first problem is the filter screen is missing. Rust coming from the tank (see below) led me to remove the petcock to clean the screen. Alas, there was no screen. Where can I get one? They seem to be nearly unobtainable. I find cheap replacement petcocks (with screen) for around $8 to $30 on ebay and Amazon. The petcock is fine and I would prefer to keep it, but I need a screen. Could I buy one of those cheap petcocks and use the screen from it? Would it fit? Any recommendations?

2. Rust in the tank. The rust doesn't seem to be bad, but it IS causing trouble. I had to put an inline filter on the bike to keep the carbs from getting stuck open. I plan on cleaning it out this weekend. I'm thinking vinegar and screws. Once cleaned, will it be ok without a sealer? I would prefer not to use a sealer. Thoughts?

3. Dents. There are some small dents in the tank that I would like to address while I'm working on it. The worst is about an inch across and lightly creased. Recommendations on how to fix them?
Helmet Vehicle Automotive lighting Personal protective equipment Motorcycle helmet
 

·
Registered
Joined
·
2,589 Posts
The petcock on my CB450 has a bowl and internal screen, not one in the tank; yours doesn't? I'd just get a replacement with the in-tank screen; after all, it's not a prominent feature on the bike, so who's going to know?

For rust, while the vinegar will remove it, it could come back as quickly as it is removed. I would suggest this, or something like it: Rust Remover - Rust Remover Spray - Eastwood Fast Etch

Fixing the dents is another issue. If you plan to repaint, then just use filler and smooth. Otherwise, I'd talk to one of those 'paintless' dent repair services, to see if they can help.
 

·
Registered
Joined
·
9,797 Posts

·
Registered
Joined
·
3 Posts
Avoid tank 'liner' chemicals if you can. Sometimes they work okay for some years, but there are plenty of sad tales of liners failing, and once they do, it's an absolute pig of a job to remove it and clean it out.
 

·
Registered
Joined
·
293 Posts
So if you de-rust a tank with say, evaporust or rustblast etc... (phosphoric acid product) or vinegar, and it's nice and shiny clean now, how you you keep it from rusting again? Not just flash rust but with an etched bare metal surface, I've not seen a good way to keep new rust at bay. Open for suggestions though.
 

·
Registered
Joined
·
2,589 Posts
That is why I linked the Eastwood product - it leaves a thin zinc-phosphate coating. You don't want to leave it empty for a length of time, but if you fill it soon after cleaning, it should keep the flash rust at bay.
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top