How to run 2 4-stokes off same tank through one separator

[bigdogg1]

Hi there,

We are running a Yamaha 15o and a Honda 9.9 off the same tank and one separator. Main power works great and kicker does as well...until it doesn't ...doesn't start, then starts great and runs for hours, then seems to starve and chokes out...

I am almost 100% sure the issue is the setup connecting all the pieces. I will isolate the kicker tomorrow off a day tank to see how it runs. The are many opinions on how to connect the main tank, the two motors and a separator. Any thoughts would be appreciated. I would prefer to stay with one separator but many advise one for each motor. Thanks in advance.

 

[Fishalot]

As long as your separator has 2 outlets it shouldn't be an issue. my kicker outlet has a check valve in the nipple that supposedly prevents the main from sucking the fuel back from the kicker however I'm not convinced that it is necessary.

 

[TheBigGuy]

Did you install the separator recently. If this problem developed after installing a new separator, check that you have the inlet and outlets connected correctly. There will be arrows for the direction of fuel flow. You can easily connect them incorrectly if you don't look very carefully.

 

[Goathorns]

I have been running an inboard-outboard and a Yamaha 9.9 for many years now, thru one Mercruiser separater with 2 outlet ports. I have a reverse check valve installed into the outlet port to the kicker to prevent the main from sucking all the fuel out of the kicker line.
When the fuel filter starts getting plugged, the kicker will be the first to show symtoms of starvation. So the main fuel filter gets changed at least once a year/100 hours.
I used a 1/4" line about 8' long to the kicker, but would recommend a 5/16ths or 3/8ths line for volume and pressure. hope this helps.

 

[bigdogg1]

Thanks for your help guys - didn't get out to isolate the motor so will try in the backyard. Managed to get to separator and pulled the whole assembly (bracket etc off the bolts to get a better look. All arrows appear to be in proper direction. Only oddity that I can see is that there is a short hose from tank to filter with a primer bulb in between (proper direction). The outlet to the kicker has a bulb in the right direction and the outlet to the main power is direct fed (no primer). I have noticed that the primer from the tank to the filter runs empty which makes sense that it then would starve the kicker. The part that doesn't make sense to me, however, is that the main power fires every time, even after the kicker has appeared to choke out. First thing first, I will isolate the kicker on a day tank and see how it performs. Thanks again!

 

[TheBigGuy]

When did this issue start. Did you make any changes to the fuel supply system or did it just slowly start getting worse. If you have two primer bulbs on the same line that may be part of the problem. You said you had a primer bulb on the line to the inlet side on the filter. Do you have two inlet feeds, or only one into the filter from the tank. If the inlet and outlet lines to the kicker both have check valves perhaps that is causing the issue.

You need to run the kicker off a spare tank with a different fuel line to exclude the motor itself as a cause. I think you already figured that part out. That is simple to do and would save a lot of wasted time and money.

If the motor runs fine off a separate travel tank, then I'd replace the hose to the kicker. If the bulb and line is older it may have a Crack or air leak you haven't noticed. Sorry, not much else I can think of.

 

[bigdogg1]

Thanks again everyone. Tried the separate fuel tank hose and primer and result was the same. Cold start worked fine, then after warming up of a minute or so, it stalled and wouldn't restart. Let it sit for half hour, it started, ran smooth then stalled again. Switched tank back to my hookup after an hour of sitting. It started first time, ran smooth, stalled and wouldn't start. Impeller has been just replaced as has the choke which mechanic thought was first problem since the motor ran for a few hours before it stalled. Apparently it is some sort of a wax that melts and rehardens when cold.

Anyways, problem appears to be in the motor since isolating the external fuel delivery didn't work. Nothing has been changed/added recently, just the new choke and impeller that has at least produced a better stream out the pee hole.

 

[Fishtank]

Sounds like you have crap in the carb exact same symptoms as mine pull out the carb and give er a good clean

 

[Sir Reel]

sounds like your float is draining and then slowly filling up over an hour or so. Either way a good carb clean up should fix it.

 

[TheBigGuy]

Run a can of seafoam gas additive through the kicker before you spend time and money on the carb. Mine was giving me issues at the start of the season. Pretty much fixed it up for me. Even if it's not 100% eliminated all the issues with the carb it's run pretty good for the entire summer after a couple of treatments. I'd rather deal with putting a motor out of service at the end rather than during the fishing season. Worth a try running seafoam through it.

 

[bigdogg1]

More great ideas - thanks. Really don't want to strip it down at this point either. Frustrating because it starts first push every time and runs on a great idle until warm, then done. Would have thought a choke issue but as is aid earlier, that was completely replaced a month agao when this first started.

 

[TheBigGuy]

Run the seafoam in a strong concentration through the kicker in a smaller travel gas tank. Clean and regap your plugs after you've used up the gas with the additive.

 

[bigdogg1]

Tried everything as mentioned, replaced and isolated all components and problem persisted until I searched online for similar issues. Had to go back farther...small bits of sand-like material were living at the bottom of the fuel tank and would work its way into the kicker carb. Drained and clean tank (buddy with fork lift to really tip it up was helpful). All good ever since...no longer get fuel at same dealer.

 

[TheBigGuy]

Tried everything as mentioned, replaced and isolated all components and problem persisted until I searched online for similar issues. Had to go back farther...small bits of sand-like material were living at the bottom of the fuel tank and would work its way into the kicker carb. Drained and clean tank (buddy with fork lift to really tip it up was helpful). All good ever since...no longer get fuel at same dealer.

Glad to hear you found the problem.