figerglas tank resin caming out in carb

Status
Not open for further replies.
850commando

850commando

Joined
Nov 1, 2014
Messages
926
Country flag
long story short, had a planned ride with the new emgo tank, and had it all mounted but the Comnoz head steady mount was banging on the tank underside and there was no time to resolve it so i remounted the dunstall fiberglas tank, by the time i had ridden 100 mi the throttle was hanging up, and it wasn't running quit right, at which point i saw some staining on the side panel and discovered the tank was leaking, so score another one for those @$$hat environmentalist and their ethanol laced fuel.

i drained the tank and capture the fuel in my jerry can, does the resin remain desolved in the gasoline or is it visible

So far i have pulled the carbs and intake runners and using acetone have been able to clean them nicely, i will run a quick compression check , hoping it hasn't got down to the bore and rings. but how far have you seen this resin go into the engine?
 
Last edited:
It should not make it past the combustion chamber. Dump the fuel but you may not see any evidence of resin.
 
It can cause severe buildup on valves - to the point of causing them to stick. This is a big problem in the marine world where fiberglass tanks were used extensively on gas and diesel higher-end boats. At the time (pre-ethanol), FG tanks were far superior to metal fuel tanks - basically being essentially impervious to leaks/corrosion/etc that eventually deteriorates metal tanks. Nowadays, due to ethanol, owners of gasoline-fueled boats are often advised to replace FG tanks with AL tanks. This is difficult because most FG tanks were formed as part of the boat's structure when it was built. :(

Interestingly, recently a marina "accidentally" had 40% :eek: (!!!) ethanol instead of the labeled 10% in their gasoline tanks, fueling many boats with that mixture before becoming aware of the situation. Damage to fuel systems on boats that refueled there resulted in a class action suit!
 
If might just be the tank fractured and some bit of debris got drawn into carbs causing the problem. Would be surprises that only a short few hours run would give severe dissolving of resins. Are you running in line filters you can check for clag?
 
Re: the Emgo tank hitting the CNW headsteady... Happened to me also and I needed to raise the tank slightly all around to clear it on the left side.
 
When my fastback tank melted with the ethanol the inlet valves were just starting to jam up
Just started to lose compression and performance
 
Last edited:
batrider said:
Re: the Emgo tank hitting the CNW headsteady... Happened to me also and I needed to raise the tank slightly all around to clear it on the left side.
Click to expand...
I made up a tank denter out of a large diameter dome head carriage bolt and used a bit of lumber to brace against one side of tank tunnel while slowly winding out the carriage bolt so head pressed the opposite side of tunnel where the Dave Taylor type headsteady was touching. Made a pretty easy job of it to get clearance.
 
FWIW re FG tanks/ethanol...I bought/installed a new FG Fastback tank from Burton's Bike Bits in 2008 that was (per them) made with ethanol-resistant resin. As an attempt to help ensure no issues, I treated it with Caswells before putting it in service. So far, no leaks or any issues. Whether that's due to the resin or the Caswells, I don't know.
 
MexicoMike said:
FWIW re FG tanks/ethanol...I bought/installed a new FG Fastback tank from Burton's Bike Bits in 2008 that was (per them) made with ethanol-resistant resin. As an attempt to help ensure no issues, I treated it with Caswells before putting it in service. So far, no leaks or any issues. Whether that's due to the resin or the Caswells, I don't know.
Click to expand...
That might be a remedy for OP's FG tank if it is to be serviceable again. I'd locate the crack/leaking area and attempt a repair with good quality epoxy thickened with reinforcing milled glass fibers. Then hit inside with a coating.
 
MexicoMike said:
FWIW re FG tanks/ethanol...I bought/installed a new FG Fastback tank from Burton's Bike Bits in 2008 that was (per them) made with ethanol-resistant resin. As an attempt to help ensure no issues, I treated it with Caswells before putting it in service. So far, no leaks or any issues. Whether that's due to the resin or the Caswells, I don't know.
Click to expand...
I treated my original 1968 tank with Caswells about eight or more years ago, & it's still fine today, fingers crossed.

Martyn.
 
I ran about 100 miles on ethanol fuel in my 71 Roadster tank before I knew about the resin problem. I became aware when the slides stuck in the carbs. Lots of resin residue in the intake ports, on the valve guides and on the valves. I used denatured alcohol to dissolve the residue, but recommend not leaving it in the intake ports too long. I noticed what looks like some reduction of the head alloy material where the guides protrude.
 
Before denatured alcohol treatment:
figerglas tank resin caming out in carb


After:
figerglas tank resin caming out in carb
 
No inline filters, the stuff was a thin sticky coating in the intake and throttle slides and wiped off really easy., gonna disassemble & soak the carbs and ensure its all out. then ensure theres none left on the backside of the valves.
NickZ said:
Before denatured alcohol treatment:View attachment 81289

After:
View attachment 81290
Click to expand...
Nickz; mine did not look that bad, and cleaned up easy in the carbs and intake, However it looks like i have black $h!t on the pistons and in the exhaust, i am down 1/2 litre of engine oil in only 220mi, and there were no obvious signs of smoke when running, so it looks like i might have to pull the head as a minimum. the engine was apart back in 1978 for a cam but not since, and it only has about 4000mi added since then. my biggest fear is the rings are stuffed.

Oh and what every liner was in there is coming off in sheets and chunks.

the Dunstall tank is not repairable and is now a museum piece, it will sell with the entire dunstall kit in the future.
 
compression was 120psi for both cylinders, over in the rebuild section i just pulled the head , looks like theres oil....

Tornado, the resin will go through the filters...
 
Ugh. Looks familiar. About 20 years ago Jeltz brought a new red glass tank supposedly made from the latest ethanol resistant resins etc. Same results as you, sticking carb slides and red goo all over slides and intake tract. Talked with the vendor, sent it back and the vendor said the tank was fine. Replaced tank with alloy (Bartells via Partidge) , no other changes, no more problems since.

I'd never trust a glass tank no matter who promises what.
 
Well...since my FG Fastback tank has been OK for 13 years now, it would seem that as of 2008, there are ethanol-resistant resins or coatings.

BUT, I agree that I would not buy an FG tank if a replacement metal tank was available. But in '08 there were no metal Fastback tanks and I haven't seen any yet...
 
After my ethanol/resin episode, the inside of the tank looked pretty good. I put 2 coats of Caswell in there, but can't give a good data point on its performance because I have been mainly running non-ethanol race fuel since. Belt and suspenders. I have just recently begun mixing some pump gas with it. So far so good.
 
MexicoMike said:
Well...since my FG Fastback tank has been OK for 13 years now, it would seem that as of 2008, there are ethanol-resistant resins or coatings.

BUT, I agree that I would not buy an FG tank if a replacement metal tank was available. But in '08 there were no metal Fastback tanks and I haven't seen any yet...
Click to expand...
If you're feeling brave, there are Indian made copies of the fastback tank available......:eek:
 
I guess that's what I would have to do should my FG tank ever fail! :( I couldn't the face returning it to a Roadster. I like the FB look too much to do that so as Monk (Nina Conti) says, "There's no going back!"
 
Status
Not open for further replies.

Similar threads

o0norton0o
amal 930's with the screw in idle jets on the underside of the carb body
Replies
5
Views
909
jimbo
jimbo
R
  • Locked
Metal shards in carb bowl
2
Replies
21
Views
2,215
Bernhard
B
jsouthard
  • Locked
Sticky Mess in Head and Carb
2
Replies
24
Views
4,365
Hobot
Hobot
Back
Top