Have a 95 40hp johnson and just purchased a kit from bps on line. I believe it is 10 micron. Should I put this between tank and bulb? Above fuel level? Please help, tired of getting carbs rebuilt. Thanks

Too bad the search feature isn't working. I believe I saw a post yesterday from one of the mechanics on the site about 10 microns being too restrictive for carbed motors. Seems like 21 microns or something like that was recommended for carbed motors. Might look a few post pages back and see if you can find that post.

Here it is:
http://texasfishingforum.com/forums/ubbt...l_W#Post7243745

Tuner, should have said also to use Stabil or Seafoam in you gas also, every tank to help keep carbs clean.

I ran a 10-micron for several years on my 40hp tohatsu. Worked great. We also run one on a '94 Evinrude 115hp works great as well.

Both installed between the bulb and tank, and mounted higher then the tank. Typically most installs will be above the tank anyway because the tank usually is one of the lowest areas of the boat. Maybe not on something like a pontoon boat.

In my experience different micron filters do not show a significant difference in restriction when new. Just make sure the filter and mount are designed to flow enough for the engine your attaching it too.

The difference is a 10-micron will clog faster then a 21 only because it is catching more, smaller junk in your fuel. You need to keep up with replacements intervals better with the smaller micron.

Many folks speak highly of SeaFoam. My Tohatsu must have been too sensitive to the extra alcohol because it ran like poop with Seafoam in the fuel. It just would not idle worth a darn anytime I used it.

Yes,install between tank and bulb above fuel tank level. You may hear you need to change filter quarterly, semiannually, yearly or whatever interval which is just WILD guessing. Any filter can get clogged in 1 day after 1st fillup from a dirty buried station's tank or it may never get clogged. Only with a fuel vacuum gauge can you tell when your filter actually needs changed. I change at 3 or 4 inches Mercury.

Excellent info everyone! Just got the thing from bps, it has 4 ports like the one above so I will just cap two of them off. Stabil seems to work fine for me.think I'll take my old paper fuel filter out since I have this new 10 micron filter. Maybe It'll increase fuel flow. Thanks!

That's great. I'd leave the other filter in place as any filter including the added 10ucron could have a manufacturing defect (hole)in it or it develop one someday.

Heres another pic better showing the direction of flow arrows in the filter housing:



And on the subject of 10ucron vs 21 ucron filters being used on carbed and injector engines:
what is most important is the filter's fuel flow rate. My big 10ucron filter actually has less resistance to fuel flow than a normal sized 21 ucron filter. It needs only about an inch or two of vacuum to lift fuel out of gas tank and filter it. My motor's spec allows up to about 4 inches vacuum.

Best to get the fuel flow data (GPH)
for your engine model and then choose an appropriate size filter with at least that rated fuel flow rate.

Then just monitor the vacuum pressure. 21 vs 10 ucron filter choice would matter little to an engine so long as fuel flow rate is fine and vacuum is in spec.

I would tend to agree in theory Lou, but the 21 made my engine run much, much better. Both were Sierra filters and I don't believe there was any difference in reported fuel flow rate. Obviously, the information isn't widespread, so I don't know if it's a universal piece of advice, but it sure helped me.