Bubbles in fuel line Westerbeke 10-2

[cbourne200]

Having had engine problems lately, I decided to rig a 'fuel polisher' & attempt to clean fuel. Boat is '87 vintage that I purchased 4 yrs ago. Don't know maintance performed prior to my purchase.

When first started having problems, installed Racor filter/water separator with 10 micron filter. Disconnected line out from filter, attached to input side of 'polisher' pump. Out line was back into tank. Hose was transparent. Drained Racor prior to start of polish. Very little water/trash. Ran polisher for 1 hour. Continuous string of bubbles from 1/4" to 1" in 1/4" fuel line. Drained Racor again, very little trash/water. Ran polisher another hour. Still a trail of bubbles. Sometimes it would clear & no bubbles, but bubbles would always return.

I'm assuming bubbles are bad... Tank is inaccessible... Decided to try blowing air back through Racor (detached line from pump & used mouth). Very hard to blow. Reversed in/out hoses on pump (thinking pick-up in tank clogged). Ran about 5 min. Reconnected properly and ran about 20 min. NO BUBBLES! Drained Racor again with lots of residue out. Didn't have 10 m filter, so left.

Could bubbles have been created due to clogged pick-up? Or cracked pick-up (no fuel leak outside of tank? Or bad fuel line from tank to Racor?

Looking for suggestions. Sorry for long post...

 

[jibes138]

It is recommended to replace your fuel lines every 10 years. I had one split once that got old and brittle so I learned my lesson. If no maintenance log was kept you might consider them suspect. Otherwise check your hose connections and you need to empty the tank and clean it. Your method of "polishing" won't get the crud out of the tank.

 

[Ron20324]

Perhaps fuel being injected back into the tank was creating bubbles? Or was the hose output lower then the fuel level?

 

[cbourne200]

Tank is 9 gal. Has about 4 gals in tank. Moved output hose around several times (deeper one time, barely in fill pipe another, all the way in another). Continued to have bubbles - didn't seem to make any difference. Tank is about 3' from deck to bottom. Fuel line as output was almost 5'.

Probably need to replace hose, but would expect to have some leak if hose was split outside tank. Unless it was pick-up that was split (split inside tank so if any leak would stay in tank). Pump output was approx 1 qt per 3 min (checked at end when no bubbles present).

As I said, tank is virtually inaccessible for a 68 yr old man with back/hip problems and 225 lbs. One reason I haven't replaced fuel line from tank is this inaccessibility. May be able to replace fuel line on tank (by removing electrical panel), but getting other end back to cut off/filter may be problem...

Why would bubbles stop when direction reversed, then set up correctly? My theory is sock is still there on pickup, clogged, and sucking air from someplace on the pickup tube. Reversing flow would open sock for a while and allow bubble free flow.

Only way I see to completely eliminate problem is to remove tank, clean, eliminate sock if present, replace all hoses, replace deck fill (to eliminate water getting in tank). Any other thoughts/suggestions?