Topic: Newbie's first post--filter screen in the fuel tank.

[SuperVel]

Hi guys!! Spent hours filling my head with wit and wisdom.  This is the right place.  Now for my problem.  Have a 1977 CB750F purchased new.  Changed jobs and was not available to burn out the gas for 10 years.  Am cleaning and rebuilding and want to flush the bad things out of the fuel tank but have concerns about the projection inside of the tank at the shut-off location.  It looks like a plastic tube about 1/2" in diameter and 4-5" long.  I cannot tell now if it has a screen inside.  It is not the reserve tube.  No one who has cleaned their tank has mentioned removing this part.  Was it supposed to have come out when I removed the shut-off??
All help is appreciated.

Marty

[Bob Wessner]

I don't know if this helps you or not, but the earlier 750 had a similar tube, and it was brass and it is the reserve tube. While in the "on" position fuel goes through the tube, in the "reserve" position the fuel went out to the lines from near the bottom. There was no filtration in the earlier ones, just a screen in the petcock assembly, and the tube did come out with the petcock assembly when it was removed from the tank.

[pwright]

Welcome Marty,

I don't know any specifics on the 750's, but here's one thing that's helped me a lot in trying to figure out how things go together:

Go to www.crotchrocket.com and user their parts fische... sometimes gives insight into the various hidden parts. The part you are in question about is listed as a "screen set" for your bike. I know on my '78 550k it's simply a plastic, slotted tube surrounded with a screen... a filter for any big junk that might be in your tank. Mine wouldn't come out the bottom of the tank, so I had to push it up into the tank and wrangle it out of the filler neck. It might have come out the bottom, but there really isn't anything to get a grip on... it pushed up into the tank rather easily.

Hope this helps...

[Bob Wessner]

Sounds like they did make a change in the later models, eh.

[SuperVel]

I thought I made a reply, but I can't find it anywhere.  Somewhere there is a big stack of totally confusing postings.

I want to thank you for quick responses to my problem.  I went to the shop and took views from top and bottom.  It is as pwright described, a screen enclosed or part of a heavier plastic cage to keep it from collapsing.  pwright, when you removed your screen, did you put it back in or just put in an in-line filter?  This thing it in there tight.  I tried to pull it out with a dental pick.  It is not going to come out easily.

Again, Thanks and Take Care.

Marty

[pwright]

pwright, when you removed your screen, did you put it back in or just put in an in-line filter? This thing it in there tight. I tried to pull it out with a dental pick. It is not going to come out easily.

Haven't put it back together yet  I don't know what I'll do... I run filters in all my bikes anyways, but it'd be nice to have that extra assurance. However, that tank screen is rather coarse, and might not catch some small debris that could clog your slow jets. I think a good deal of the guys here run inline fuel filters.

To get mine out, I tried catching a corner of it with a needle nose and pulling it out, as well as with a pick. Didn't want to come out. So, I took a dowel about the same size as the screen, and lightly tapped it through to the inside... it went that way much easier. So, I have the screen out, and the bottom is a bit chewed up from the pliers. I think I'll throw it back in and run a fuel filter also. As far as I can tell on mine, the bottom of the screen doesn't seat on anything so leaving it out wouldn't be a big deal, either, don't know about your model.

Another tip: once you get the Honda part number off of crotchrocket.com, go to the Western Hills Honda site www.westernhillshonda.com and look it up in their parts inventory... it will tell you how many they actually have in stock and their price, unlike a lot of sites which won't tell you if it's in stock when you order it.

Good luck, and you've come to the right place for SOHC answers. I'm a relative newbie myself, but have learned a TON just by reading old posts.

Later,
-Pat-

[mick750F]

    It should come out easily with a tap from the inside. I recently had mine out with the same bike as yours and that's how I did it. I re-installed it and used an in-line filter as well.

Mike

[TwoTired]

Oh my,
I have to disagree with previous posts.

1: By 1975 the fuel petcock and filter changed design to a much finer mesh inside the tank surrounding a nylon standpipe for main fuel supply.

2: The in tank fuel filter is very fine.  It will only pass particles about one hundreth of the smallest orifice in the carbs.  Particles this fine won't even block the float valve.

3: DO NOT drive the filter and stand pipe assembly into the tank!  The nylon base has a shoulder molded into it to prevent it from going into the tank.  Surely driving it in with a dowel will render it useless.

4: Yes, they can be difficult to remove. They are keyed so they can't rotate, too, and must be drawn straight out. Use a brand new needle nose plier with deep serrated jaws to grip or bite into the nylon and pull it straight out. The mesh is quite fragile though.  So, take care not to damage it with abuse.

5. I know most people on this list get a woody when inline filters are installed on a bike.  However, I don't use any but the very good one in the tank, as it keeps the carbs as clean as they need to be.  If the in tank one is destroyed, then there is no choice but to fit inline ones, of course.  But, there have been several posts describing routing and feed problems with inline filters.  None of which, I have first hand experience, because I repair the in-tank type and discard any external in line filters I have found on bikes that cross my path.

Cheers,

[Bob Wessner]

I don't use any but the very good one in the tank, as it keeps the carbs as clean as they need to be.

One of the many advantages of the later models. The earlier, at least the 750, only had a wire gauze screen in the petcock assembly, so in-lines seem like a logical safeguard in an aging tank.

[SuperVel]

Ho Boy!!

Okay, TwoTired says to push or pull it through the bottom.  If so, could I fashion a curved tool and apply pressure directly down and out of the hole?  And, it looks like a cap on the top of the pipe that may be added to or molded on making it a one piece deal.  If I force or pull it out through the shut-off hole, will it have enough room?  Is it strong enough to take this sort of movement??

pwright, did the bottom of the tube survive in a way that would allow it to be re-installed in the tank?

Thanks and Take Care

Marty

[78_SaltLick]

Oh my,
I have to disagree with previous posts.

1: By 1975 the fuel petcock and filter changed design to a much finer mesh inside the tank surrounding a nylon standpipe for main fuel supply.

2: The in tank fuel filter is very fine.  It will only pass particles about one hundreth of the smallest orifice in the carbs.  Particles this fine won't even block the float valve.

3: DO NOT drive the filter and stand pipe assembly into the tank!  The nylon base has a shoulder molded into it to prevent it from going into the tank.  Surely driving it in with a dowel will render it useless.

4: Yes, they can be difficult to remove. They are keyed so they can't rotate, too, and must be drawn straight out. Use a brand new needle nose plier with deep serrated jaws to grip or bite into the nylon and pull it straight out. The mesh is quite fragile though.  So, take care not to damage it with abuse.

5. I know most people on this list get a woody when inline filters are installed on a bike.  However, I don't use any but the very good one in the tank, as it keeps the carbs as clean as they need to be.  If the in tank one is destroyed, then there is no choice but to fit inline ones, of course.  But, there have been several posts describing routing and feed problems with inline filters.  None of which, I have first hand experience, because I repair the in-tank type and discard any external in line filters I have found on bikes that cross my path.

Cheers,

Good lord two tired i think you were born on a honda......how could one know so much about every part of the bike!

[TwoTired]

I never said to push it, as I think there is too much risk of damaging the screen.  Though, honestly, I've never tried it that way. The one I'm looking at in my hand right now has the screen pinched together at the top of it.

I pull them out from the bottom as described earlier.  The screen mesh is quite soft and will easily yeild to the entrance hole if side loads aren't too extreme.

cheers,

[SuperVel]

Okay, I think I have a course of action in my mind.

I am going to remove it and if it is in good shape, re-install it after I clean the tank.  I have visited crotchrocket.com and was happy to be able to gather parts numbers and descriptive names.  I got the Western Hills Honda telephone number from a woman at American Honda in California.  I also found Honda Parts Direct which shows prices "less expensive" than crotchrocket. 

Thanks to all for your help, take care.

Marty

[SuperVel]

Three cheers for all of you.   I couldn't have done it without your help.

I went out to the shop and reworked a dowel so that it had about .004 difference along its length for each 2 inches.  I stuck it in the bottom of the tube and was gently pushing to see if I could get it to pop into the tank.  When it stopped, about halfway to the top of the tube, I turned the dowel to free and remove it.  The filter tube rotated with the wood dowel and I pulled them both out without a mark or scratch. It is scuzzy but in beautiful shape.

Thanks for the help.  It's like having a group of friends standing by while you are trying to perform delicate surgery.

Take Care

Marty

[TwoTired]

Good lord two tired i think you were born on a honda......how could one know so much about every part of the bike!

Well, I've had my 74 Cb550 since 75. A wreck, which I tore down to the frame and rebuilt with pieces that weren't bent (a lot of them).  Then there were the 15 Hondas since then that I rebuilt, restored, or dismantled.  You may have noticed my current collection, below, initially received as derelict, disheveled, problem cases, previous owners gave up on.  Resurrection games for me.

Then there is the fact that my memory function is dominated by visually oriented images.  So far, it's still working fairly well, as best as I can recall.