I found some debris in the fuel tank of my old Honda CT90 Trail motorcycle. Time to clean the carb and fuel tank. After trying to clear out the tank, I found that it has some sort of coating that is coming apart and getting into the fuel system.

 

No big deal, I have a parts bike with a good tank that does not have this.

I bought the bike in question from the original owner who bought it new in '72. He never said anything about coating the tank, and I've never coated one to know what it looks like.

 

Can anyone tell what this is? The stock tank is just steel on the inside and outside.

 

It looks grey or green???

Could be an epoxy, it's not RedKote

Here's some silver/gray stuff.  There have been probably been many different colors over the years.

 

My 1st bike was a CT 70. My Dad bought that before he bought me a bycycle. He lived way out in the county. No kids my age to get to by a bycycle so he got me a mini bike. Great Dad decision.

 

 

 

53 minutes ago, Zed Head said:

Here's some silver/gray stuff.  There have been probably been many different colors over the years.

 

Thanks, I'll bet it's something like that. Too bad its coming apart, I'm not sure I'll be able to tend to it without splitting the tank in two. 

 

37 minutes ago, siteunseen said:

My 1st bike was a CT 70. My Dad bought that before he bought me a bycycle. He lived way out in the county. No kids my age to get to by a bycycle so he got me a mini bike. Great Dad decision.

 

 

 

Those are great little bikes!  I run my CT90 about twice a week in the winter and regularly to work in the summer, only 8 miles from my house.  Mostly for fun but now that gas doesn't seem to be going below $4.00 a gallon here it's nice to get 90+MPG.  Premium only in the Z gets it driven about twice a week too if it's lucky. 

Most bike shops I worked at sold a product call Kreem. A white three part coating. even back in the late 70's and 80's

https://www.kreem.com/fueltankliner.html

I suspect there is rust under the coating, bubbling it up. I also suspect muriatic would strip it off one it started getting under it. Put some bolts or rock or something in the tank and gently shake for some extra cleaning action

Been watching some videos, looks like bolts in the tank are key to agitating everything. Thanks for the tips.