Primer ball not staying hard

[slaydown]

Hey Boys,
Well i just returned from bamfield and was have problems with my motor. I have a 91 suzuki dt 100 and when giving throttle it would sometimes bog out and die. I noticed that my primer ball was not staying hard and if I gave it a couple of pumps she would be fine. Now I have narrowed it down to hopefully a bad ball or my diaphragms are gone in the fuel pump. Now before I start repairs was wondering if anyone has had any experience with this. Any input would be greatly appreciated.
Cheers

 

[Island Fish Lifter]

sounds like diaphragms, may also be sucking air.

Fill the dam tub!

 

[Hoochiebob]

Diaphragms.major increase in gas consumption will also indicate a bad diaphragm as the gas will bleed out through the water exhaust.Easy fix and the parts should be fairly inexpensive.
A bad ball valve will almost never pump up hard


Hooch

 

[profisher]

I would replace the primer bulb first and make sure it is hanging with the tank end lower than the engine end. A bad diaphragm will usually foul plugs badly as one or more cylinders are flooded with raw fuel in a 2 stroke.

 

[Island Fish Lifter]

its an easy check. Remove the fuel pump from the engine with fuel lines attached. Pump bulb. Fuel should not leak from pump. If it does, bad diaphragm. Dont go changing parts until you troubleshoot it first.

Wheres Charlie to argue this one with me?[]

Fill the dam tub!

 

[Barbender]

I just take Viagra. Works every time.

 

[yammy5]

Flat ball Syndrome ~ had it on 2 boats. In both cases there was a fuel restriction in the fuel tank and it was starving the engine of fuel. As the engine trys to draw fuel the primer ball becomes flat. In the first case, there was a build-up of 'gunk' that accumulated in the bottom of the tank and started to block the filter at the end of the fuel line. We ended up replacing the fuel tank. It was old. On the second boat we also replaced the tank but the actual problem was the anti-syphon valve. Over time the valve accumulated 'gunk' and started restricting the fuel flow. At full throttle the engine would just quit (fuel starved). Didn't even know there was a valve until we took everthing apart.

So IF it's not a problem with your actual primer ball then check your lines for fuel restrictions and look for an anti-syphon valve. Hope this helps ~ I wish somebody had given me this advice because it can be a painful process finding the problem.

Good Luck!

 

[TheRock]

On our second boat here the fuel restriction was so bad it caused one of the diaphragms in the motor to rip. At the time we did not know what happened. When we brought the boat in they opened the motor and found the ripped diaphragm and replaced it. Even the pro mechanic at the shop did not solve or figure out the actual problem that was causing this. We had to figure it out on our own. We pulled out the feeder tube from inside the gas tank. In the feeder tube there was an internal mesh screen filter! we had no idea that was there.. it was also clogged up. The anti siphon valve is part of that feeder tube at the top. In side the anti siphon valve The spring inside that holds the ball bearing against the end to stop the fuel from anti siphoning was stuck. The motor had to suck gas against the force of that stuck spring causing the fuel restriction and intense force starving the engine and causing the diaphragms to RIP!. We took it apart and put the anti siphon valve in a vise and smashed out the ball bearing and spring so there is a free open flow now. The anti siphon valve is only needed if the motor is below the level of the gas tank. We removed the old in line mesh filter as well so the feeder tube in the gas tank has an open flow. We run a Racor fuel/water separator filter from the gas tank any ways so there was no need for the old style in line mesh screen filter in the gas tank feeder tub any more... I must say the engine runs 100% now, hole shots are instant the boat comes up to plane right away, what a huge difference in performance when you don't have a fuel restriction.

quote:Originally posted by yammy5


Flat ball Syndrome ~ had it on 2 boats. In both cases there was a fuel restriction in the fuel tank and it was starving the engine of fuel. As the engine trys to draw fuel the primer ball becomes flat. In the first case, there was a build-up of 'gunk' that accumulated in the bottom of the tank and started to block the filter at the end of the fuel line. We ended up replacing the fuel tank. It was old. On the second boat we also replaced the tank but the actual problem was the anti-syphon valve. Over time the valve accumulated 'gunk' and started restricting the fuel flow. At full throttle the engine would just quit (fuel starved). Didn't even know there was a valve until we took everthing apart.

So IF it's not a problem with your actual primer ball then check your lines for fuel restrictions and look for an anti-syphon valve. Hope this helps ~ I wish somebody had given me this advice because it can be a painful process finding the problem.

Good Luck!

 

[TheRock]

quote:Originally posted by slaydown

Hey Boys,
Well i just returned from bamfield and was have problems with my motor. I have a 91 suzuki dt 100 and when giving throttle it would sometimes bog out and die. I noticed that my primer ball was not staying hard and if I gave it a couple of pumps she would be fine. Now I have narrowed it down to hopefully a bad ball or my diaphragms are gone in the fuel pump. Now before I start repairs was wondering if anyone has had any experience with this. Any input would be greatly appreciated.
Cheers

Hi Slaydown, I got your message, so glad we could help out, I don't wish that anti siphon valve [}] issue on no one... glad you got it fixed. [^] []

 

[Gerblue]

Hey Boys,
Well i just returned from bamfield and was have problems with my motor. I have a 91 suzuki dt 100 and when giving throttle it would sometimes bog out and die. I noticed that my primer ball was not staying hard and if I gave it a couple of pumps she would be fine. Now I have narrowed it down to hopefully a bad ball or my diaphragms are gone in the fuel pump. Now before I start repairs was wondering if anyone has had any experience with this. Any input would be greatly appreciated.
Cheers

I have a DT100 also ... on a boat I just bought ... had is serviced ... ran great on the lake ... shut it down for lunch and drifted for about an hour ... wouldn't start ... all the way home on the kicker ... parked boat at home and it started right away ... anyone have any ideas ?

 

[Rain City]

This is a record resurrection.

 

[Captain PartyMarty]

Some bad advice there as well. Removing the anti siphon is so bad. If any fuel line ever leaks it will drain your whole tank into your bildge..

 

[wolf]

If any fuel line ever leaks it will drain your whole tank into your bildge..

REALLY never heard of that ,, now ive seen some guys fill the in deck rod holder before not the fuel tank.... I too have got rid of a few anti syphon valves in my time some are complete garbage...
curious though how can a tank thats below deck with a pick up tube drain into bilge as most anti syphons are at the filter...

 

[Captain PartyMarty]

If that fuel hose breaks loose and drops into your bilge would be one example.

Anti Siphon valve must be installed at the tank outlet if they are installed at the filter that's wrong.

1. fitting an anti-siphon demand valve at the fuel line to tank connection that can be opened only by the fuel pump suction to withdraw fuel from the tank and that will remain closed when the fuel pump is not operating, thereby preventing siphon action created by a break or leakage at any point in the fuel distribution system.

Granted that the Boat building rules allow for no Anti Siphon valve if you can guarantee that no fuel hose length can not reach a level lower than the tank pick-up. But if the boat Manufacturer installed an anti-siphon than he likely had concerns about it happening. The valve is there for a reason and just blindly telling somebody to remove it is in my opinion dangerous and careless. If you know what your doing like I am sure you do then yes by all means remove it. If there is fire on your boat I am sure the insurance company will have that on there check list of reasons to deny your claim....

 

[Sharphooks]

Wouldn’t be a bad idea to check your fuel/water separator if you have one. If you’re shooting blanks trouble-shooting the items indicated above, make sure your filter has a good prime of gas and there are no leaks around not only the “O” rings but the brass fitting going into the housing. I’ve gone through flat ball syndrome multiple times and both times it was the fuel water separator (pin hole leak in the brass fitting when someone over-tightened, and a lost prime in the filter itself when trying to drain gunk out of the Raycor plastic bowl which caused the filter to lose its prime)

 

[wolf]

If that fuel hose breaks loose and drops into your bilge would be one example.

As for a hose falling off .that rare as seeing a sasquatch i have never seen that and ive seen some weird things fish tank tubing for one

Well I know for a fact as I have to have shut off valve at tanks as per the inspection that I need every 5 years and under that as well it needs to be A1 hose and connections have to be double clamped and not with the normal hose clamps needed to be special hose clamps, not once was a anti siphon valve EVER mentioned.

 

[Wild Bill]

Since all of the valves I have typically seen in any equipment I have worked on they typically are in the fitting that screws into the tank with the pickup tube attached and just prevent drain back of the fuel line into the tank so you don't have to suck air and have to deal with a huge air bubble every time you start the engine.

 

[Captain PartyMarty]

As for a hose falling off .that rare as seeing a sasquatch i have never seen that and ive seen some weird things fish tank tubing for one

Well I know for a fact as I have to have shut off valve at tanks as per the inspection that I need every 5 years and under that as well it needs to be A1 hose and connections have to be double clamped and not with the normal hose clamps needed to be special hose clamps, not once was a anti siphon valve EVER mentioned.

If you Read the code having a shut off valves at the tank outlet is also a valid option if Anti-siphon valves are not wanted. All I am pointing out is the guy's punching out the check valves and then not making sure they have an alternate safety measure in place is dangerous.

https://tc.canada.ca/en/marine-tran...-standards-small-vessels-2010-tp-1332-e#wb115

Section 7.4.8 outlines requirements for anti-siphon protection your solution of hand valves in perfectly valid, not doing anything or disabling a protection is not a good choice.

 

[wolf]

Agreed i wouldnt punch it out just replace it if it were me.

 

[Wild Bill]

I was actually surprised the amount of spring pressure and restriction but kept it The BBC boat has a Carter 5 psi electric in front of an OEM mechanical diaphragm.