Spin on fuel/water seperator unit bad????

[Steve8686]

3.0 mercruiser stumbled, bogged, wouldnt start. Put on new fuel/seperator filter, same symptoms. Went from tank right to fuel pump bypassing the filter and ran like a top. Checked hoses, connections, going to from seperator no fuel drips ect, Can the seperator unit itself be bad? Ive had this happen a couple times now. Anyone else have this happen and had to replace whole unit.

 

[achris]

Re: Spin on fuel/water seperator unit bad????

Could be a bad spot on the sealing surface, allowing air to be sucked into the fuel system.... Or the fuel line fitting barbs have been screwed in too tight and cracked the body, allowing air to be sucked into the fuel system...

Chris.......

 

[Don S]

Re: Spin on fuel/water seperator unit bad????

You didn't use teflon tape on the fittings did you?

 

[Steve8686]

Re: Spin on fuel/water seperator unit bad????

You didn't use teflon tape on the fittings did you?

Thanks for replies, No, I didnt put the unit on, all service was done by Kent marine in Kent Wa before I bought it. I seen in a service manual they reccommended pipe thread dope. Anyway, almost makes me want to go back to an inline fuel filter, this thing has really perplexed me tearing into the carb runs then dosent run. accelerator pump, no its not that, pumps fuel fine, fuel shoots out of the pump, not fuel pump. Then find this when this is supposed to be a upgraded system from inline fuel filters. KInda scares me to go back to the same system.

 

[spdracr39]

Re: Spin on fuel/water seperator unit bad????

How old is the fuel? Could it be bad ?

 

[Don S]

Re: Spin on fuel/water seperator unit bad????

Thanks for replies, No, I didnt put the unit on, all service was done by Kent marine in Kent Wa before I bought it. I seen in a service manual they reccommended pipe thread dope. Anyway, almost makes me want to go back to an inline fuel filter, this thing has really perplexed me tearing into the carb runs then dosent run. accelerator pump, no its not that, pumps fuel fine, fuel shoots out of the pump, not fuel pump. Then find this when this is supposed to be a upgraded system from inline fuel filters. KInda scares me to go back to the same system.

I don't really care who installed it, is there teflon tape used on the fittings? That stuff should not be on a boat because it causes more problems than it cures. When you changed the filter element, did you make sure the old gasket came off the housing. Wouldn't be the first filter with a double gasket that won't work. Really makes a mess when it's an oil filter.
Since you don't think the fittings are the problem, and you don't think it's the filter housing is cracked, then just replace the thing with a new one.

With todays fuel, you need a water separating fuel filter. But if it's not installed right, it's not going to work, and an inline filter is not a water separator.

 

[Steve8686]

Re: Spin on fuel/water seperator unit bad????

You didn't use teflon tape on the fittings did you?

It looks like teflon tape and maybe nothing on the other 2 fittings. Brand new gas non ethanol is all that goes in this ol girl. No double gasket, Can water even accumulate in the gas if you are turning gas over every 2 weeks and using non ethanol. Storage i understand is another story.

 

[Don S]

Re: Spin on fuel/water seperator unit bad????

Take all the fittings out, clean the threads, and using fuel resistant pipe thread sealer or aviation gasket sealer, reinstall all the fittings without overtightening them.

Next, empty the contents of the filter element into a clear container and see if there is water in it. Water will sink to bottom.

DO NOT reuse the filter element, put a new one on and pre-fill it with clean gas and use some oil on the gasket (DO NOT USE GREASE).

Then start the engine see how it runs. You may have to pour some gas in the carb a couple of times to get it running.

 

[Steve8686]

Re: Spin on fuel/water seperator unit bad????

Take all the fittings out, clean the threads, and using fuel resistant pipe thread sealer or aviation gasket sealer, reinstall all the fittings without overtightening them.

Next, empty the contents of the filter element into a clear container and see if there is water in it. Water will sink to bottom.

DO NOT reuse the filter element, put a new one on and pre-fill it with clean gas and use some oil on the gasket (DO NOT USE GREASE).

Then start the engine see how it runs. You may have to pour some gas in the carb a couple of times to get it running.

Thanks alot for all the input.