750 proper fuel size fuel filter

[nutsandbolts]

Hey there,
Anyone know what the proper size fuel filter is supposed to be on a 78GS 750 with vm26 carbs?
Even my suzuki shop doesn't know.

 

[BassCliff]

Hi,

If your tank and carbs are clean, there is really no need for an inline fuel filter. Most are too restrictive anyway. If you must use an inline fuel filter, get a "gravity only" filter, like for a lawn mower. An automotive filter requires a fuel pump, which these bike do not have. The filter at the top of your petcock is usually enough.

Thank you for your indulgence,

BassCliff

 

[Steve]

And, ... anything that happens to get by the filter at the petcock should get caught by the filter at the float valve of each carb.

.

 

[nutsandbolts]

thanks guys,
I'll post pics this weekend of what was on there, what I replaced it with (not working) and what I ordered (gravity drop i think)
Appreciate the feedback.

 

[Nessism]

Those gravity feed type fuel filters are more like strainers and are no more effective than the screen in the petcock. Better than nothing as long as the filter doesn't create a loop in your fuel line, in which case nothing is preferred.

 

[nutsandbolts]

I'm guessing these bike never came with a filter from the factory?

What do you mean by "loop"?

 

[Nessism]

I'm guessing these bike never came with a filter from the factory?

What do you mean by "loop"?

The fuel system is gravity feed so the fuel line needs to go straight down from the petcock straight into the carbs. When people install a filter, which is difficult to package in the tight fitting area, sometimes they create an uphill path for the fuel to flow into the carbs. The gas will still flow to the carbs when the gas tank is full but when the level is low the carbs may starve.

Regarding the stock system, the petcock has a screen (filter of sorts) and there are similar screens on each float needle. Junk can still get past these "filters" though so keep this in mind if your gas tank is full of rust.

 

[nutsandbolts]

Hey thanks Ed,
Took out the improper filter and ran straight tube from tank to carbs. That stopped my starting problem. Ran well after that though I'm still getting a little idle irregularity. Sometimes its bang on 1000 rpm at a stop, other times it 1250-1500.
That leaves only valve shims, and interior carb orings to change. eveyrthing else is new oem.
I'll do these two next and see what happens.

 

[jknappsax]

Ed, I've never seen any screens for the float valves on my VM 26s. Which carbs are they on?

 

[Steve]

Ed, I've never seen any screens for the float valves on my VM 26s. Which carbs are they on?

I think I have only seen them on the BS series carbs. :-k

.