Why no inline fuel filter ?

[mike10]

I have a 1980 GS1000. It had an inline fuel filter on it when I got it, so I got a new one and put it on. Since then I have coated the inside of the tank so I don't need it but I left it on. I have only riden it a few miles but it doesn't seem to hurt anything. But I have seen it said several time on here No inline fuel filter. Why?

[gearhead13]

I have a 1980 GS1000. It had an inline fuel filter on it when I got it, so I got a new one and put it on. Since then I have coated the inside of the tank so I don't need it but I left it on. I have only riden it a few miles but it doesn't seem to hurt anything. But I have seen it said several time on here No inline fuel filter. Why?

There may be different reasons for saying to not run an inline filter. Can't think of a good idea to not run one though, as long as it is a proper motorcycle filter for gravity fed systems.

[79FiveFifty]

The only reason (I can see) would be because the petcock has a built on filter which is just as effective as most inline filters.

Some people have said it impedes the flow, and causes lean issues or crappy throttle response that I have read, but if you aren't having an issue it's not an issue.

[67fire]

When I converted my '79 750 to a 850 with CV carbs, it would suck them dry if it was not on PRI at the petcock.
Perhaps an in-line filter would be too restrictive for CV carbs?

Eric

[paco13]

I run one on my 1100, 5/16 metal screw together type with brass filter. The only flow prob I had was the line would kink where it makes the sharp turn down between carbs once the tank was lowered into place. I plumbed in a right angle bend brass hose union and no more probs.

[Octain]

Why no inline fuel filter ?

They're very ugly!

I filter mine as I put the fuel into the tank as I know for fact my tank is very clean.

[Steve]

The biggest problem with fuel filters is that many (most?) of them are purchased at the local auto parts store. Filters designed for cars can be a bit restrictive, as ALL cars have a fuel pump to move fuel from the tank to the engine. That pump will force the fuel through the filter with no problem. Our bikes, however, rely on gravity to pull the gas from the tank to the carbs and the relatively low head height is not enough to force the gas through some of the more-restrictive filters.

If you insist on installing a filter, just make sure it is designed for a gravity-fed fuel system. You might be able to find one labeled 'motorcycle', but it is far easier to find one for a lawn mower.

One other thing to keep in mind: in stock configuration, your bike already has two filtration points before the gas gets into the float bowl. There is one filter around the petcock intake, then another filter that snaps onto the top of the float valve in the carb. Make sure those are in place and in good condition, you won't really need anything else.

.

[Octain]

One other thing to keep in mind: in stock configuration, your bike already has two filtration points before the gas gets into the float bowl. There is one filter around the petcock intake, then another filter that snaps onto the top of the float valve in the carb. Make sure those are in place and in good condition, you won't really need anything else.

.

Does the 80 model have CV carbs?

[Steve]

Does the 80 model have CV carbs?

Let's just say "it did when it left the factory."

You never know what some previous owner might have done.

.

[Flying Fish]

I was having problems with my gs1000 running lean and cutting out after a about 5 miles when holding a steady 75mph. I removed the inline petrol filter and the problem disappeared. As has been said, some filters are to restrictive for gravity systems. If your not having problems with lean running or the engine "hunting" then your filter is probably ok.

[mike10]

fuel filter

The filter I have is for a motorcycle and It has CV carbs. I guess if I have a problem with it I won't put on another. Thanks For the Info. I hope Santa brought you all something nice.

[ianralph]

I found that when I put a proper motorcycle in-line fuel filter on my GS1000SN ('79) it got in the way of the choke mechanism and made the choke difficult to apply and tended to stop the choke from returning to the off position. In the end I had to buy a very small filter.

I think the extra filter is worth having as you can easily see if there is something clogging up the system - the filter in the tank and the one in the petcock are not so easily inspected.

BTW I haven't had any problems with fuel starvation since adding the filter.

[tfb]

I was having problems with my gs1000 running lean and cutting out after a about 5 miles when holding a steady 75mph. I removed the inline petrol filter and the problem disappeared.

The reason inline filters should be avoided is precisely because of the above problem, ie. the dreaded VAPOR LOCK.
The filters inevitably trap a bubble of air inside them. As the engine warms up, the filter gets hotter and the bubble expands, making the progress of liquid fuel through the filter v-e-r-y slow.
The same thing will happen with fuel line which falls and rises in its journey to the carbies; if you get a bubble of air trapped in the line, it will sit at one point and expand to create problems as the temp. of the fuel line increases, there behind the engine. Always make sure that you fuel line follows an ever-descending route to the carbies.