Fuel Line Woes!!!

[barfwinkle]

GM to All and Happy Labor Day

Well yesterday marks the second Sunday in a row that Rhapsody has headed for port only to find a fuel leak on the primary filter (assuming the filter on the engine is the primary). The "twist lock" has vibrated loose on each occurance. Thankfully, yesterday I caught it before it could dump several gallons of diesel into the bilge (as happend a week ago). Took all week to clean it up and dispose of it properly.

I have been pondering this "all of a sudden" issue since returning to the slip yesterday. Here is some background.

1. I have owend Rhapsody for going on 18 years and this has NEVER happenned before
2. This Saturday I motored in no air for two hours without incident.
3. heading for another anchorage yesterday I was bucking heavy boat traffic, strong opposing current, and a pretty good head wind.
4. I have put about 110 hours on the engine since January without incident.
5. I installed a new prop shaft and aligned it back in December once she was in the water.
6. I installed engine mounts in Novermber 1997 and until now there has never been an issue (if now).
7. By the nature of the beast, the Yanmar 1GM (affectionately known as Thumper) is a rough running little bugger and its hard to discern more from less vibration (at least for me).

Now the only thing I can think of is that vibration is causing the "locking ring" on the filter housing to back off! Why?

1st I didn't get the shaft aligned properly?
2nd, the engine mounts are bad!

IF the lockiong ring is vibrating loose, then what is causing the vibration? Doesn't it have to be one of the two sources listed above? And arent the two interrelated?

I can ajdust the shaft again, but that means adjusting the mounts, so I'm thinking why not just go ahead and replace the mount first then readjust the shaft!

Comments and or suggestions please!

Fair winds

[Jim Walsh]

I'm not familiar with the engine so I took a look online. Your primary filter housing appears to be a bolt on component. I believe the problem lies with the filter housing itself. Perhaps the locking ring is worn. I would remove it from the engine and inspect the individual components of the filter housing very carefully.

Were I in your shoes I'd replace the "fuel strainer assembly" in a heartbeat. It's only $58.
http://shop.toadmarinesupply.com/ships_ ... 4790-55601
I don't have your engine serial number so this may not be the exact replacement but it's in the ballpark.

[tjr818]

I'm not familiar with the engine so I took a look online. Your primary filter housing appears to be a bolt on component. I believe the problem lies with the filter housing itself. Perhaps the locking ring is worn. I would remove it from the engine and inspect the individual components of the filter housing very carefully. . . .

And Bill, while you are replacing it I would think about moving it off of the engine and onto a bulkhead. On our YSM8 it is a bear to get to and hard to get a wrench on. That is one of our projects for this winter. I see no need for it to be mounted on the engine.

[Joe Mac Phee]

Bill,

I have the YSB-12 with the same filter. My experience is like yours, it has not been a problem for 25 years. Whenever the young enginers who worked for me had some anomalous problem, I would ask them "what did you do last"?

Was the filter changed this year? Check that the O ring on the top of the cup is there. Check that there are not 2 O rings.

I use a strap wrench to get at the filter retaining ring.

Since the shaft was replaced, check that there are no loose bolts; coupling, prop, mounts.

I believe the best location for the filter is on the engine, no relative motion between the engine and the filter.

Both my engine and yours are "Thumpers". But to be fair, they smooth out when rev'd up because of the momentum in the very heavy flywheel.

Good luck

Joe

[Steve Behnke]

Be sure to check the locking ring -- on my YSM8 it eventually became cross threaded and wouldn't stay tightened.