Racor vacuum gauge

[Keith]

I just installed a racor vacuum gauge and I can barely get a reading in it. I first installed it in the extra output port and it barely moved off zero. I bleed the system several times but no change. Then I moved it inline between the filter and the fuel pump and the same results. My filter is 2 years old with maybe 100 hours on it. I expected to see that it would have a lot more vacuum and probably show that it needed to be changed. Looking to see what others who have installed the vacuum gauge have seen. See pics below of the final install. In the first pic the engine is running and you can see the gauge is barely off zero. When I shut the engine off the needle does move back to zero and when I pump the manual fuel pump lever the needle does bounce a bit.

Keith

fuel filter gauge.jpg (94.27 KiB) Viewed 592 times

fuel filter gauge 1.jpg (75.73 KiB) Viewed 592 times

[tjr818]

I though the gauge was supposed to go on the in the output side of the filter.

[Keith]

It is between the fuel filter and the fuel pump connected to the out side of the fuel filter. I don't understand what you mean by "inout side" of the filter. My racor filter has one in port and two outs ports. It is a 500 series fuel filter/water separator.

Keith

[Steve Laume]

I have had a vacuum gauge in my fuel system for many years and I have never seen it register much of anything. Mine is an early model without the pointer so I only check it on occasion and don't know what it does when I am running at high RPMs. The gauge has lead me to believe that most people change fuel filters far more often than necessary. These small engines are not ever calling for much fuel so there isn't much pull that would create a vacuum with very little restriction.

My feeling is that your gauge is showing you exactly what you want to see, Steve.

[Keith]

Thanks Steve,

Thats what I thought because it does seem to respond the way is should just very little movement. At this rate I may never have to change my filter. As a side note my tank is very clean I took it out several years ago and flushed it out throughly.

Have you ever seen yours go int the yellow or red? What reading do you see?

Keith

[John Stone]

Over on my engine thread we just discussed this. I bought one. Tim Lackey and I discussed it. I returned it. In my case I have a new fuel tank, engine, and support system. There should be nothing in the tank but clean fuel provided I get good fuel. The sense was I would not use the engine enough to make maximizing the life of the filter an issue. Just change it regularly. Also, there was a sense the Beta 25 just doesn’t pull much fuel. So, as I said, I returned the gauge.

I’m just passing along my thinking which, in this case, is more academic knowledge than practical engine experience.

Probably not much help.

[Keith]

Thanks John,

Yes, I saw your post and that is what made me think of posting mine. I didn't want to jump your post so I started a new one.

Can't wait to see that shinny red engine in Far Reach.

Keith

[John Stone]

Oh there has been wide ranging discussion there so no worries at all. But, I think a separate thread on a vacuum gauge is a good call so folks can easily find it. I am definitely interested in the discussion here by those with experience on the topic.

[Steve Laume]

Mine has never registered much of anything. Certainly not into the yellow.

I put it on when I still had my old tank which has since been replaced. I was never sure how often the fuel filter needed to be replaced. At that point in my sailing career I was using the engine as little as possible and it seemed like an annual change was excessive. My old tank was very clean when I pulled it and the new one should be as well. I now observe the gauge every so often and change out the fuel filters every couple of years. The last time I went to change it the spares were rusty, even after being stored in a plastic container. I sprayed the new spares with WD-40.

While the gauge may not be necessary, it is also not expensive. If I were to pick up some bad fuel or have a glob of crud grow in the tank, that clogged the filter, I would know. I look at the gauge as a trouble shooting device. If I were ever to have engine issues, a glance at the gauge would confirm that it was not because of a clogged filter or fuel line.

I say keep it as knowledge is power or in this case independence, Steve.

[Steve Laume]

I would think it was even more prudent to have a vacuum gauge if you don't use your engine very often. The majority of your fuel could be sitting in the tank for years, Steve.

[gates_cliff]

Steve, I think this last point is a very good one. I filled my tank last year, and checked it recently, it's still 3/4 full. I motor as little as possible but was thinking about crud build up possibility. This thread reminded me that I need to change my filter!

[Keith]

Update, I hauled out 2 weeks ago and the gauge has still not moved any higher even at high RPM's. As stated earlier this filter is 2 years old with maybe 100 hours on it. I'm not going to change it and monitor if the vacuum level next year. Will keep you updated

Keith

PS I do have a spare ready