Rodbolt 17 please help!!

[dorado42]

***...GREAT explanation Rodbolt17....I will have to catch up with you and find out what the brand of ethanol you are low on; your wisdom and experience clearly are respected and APPRECIATED. I shared your email with a buddy of mine that has been helping me (2 stroke experienced but no experience with 4 stroke) and he stated your explanation of the problems caused by leaking valve was like you were on the boat with us. I will follow up on results. THANKS AGAIN!!!!!!!

[liliepad1]

I do agree most likely the valve leaking but i thought it was check long ago .

[dorado42]

No it was not checked long ago... it was believed that there was a fuel restriction, due to motor ran fine on portable tank. The issue is the problem is sporatic, sometimes it does it sometimes it does not. It appears the portable tank test was a false positive. The problem occurred and then switched to the portable tank and problem went away. Therefore it was believed to be a fuel restriction problem. After checking the entire fuel system to include new low pressure pump the problem is still occurring. Hence the reason we are discussign the valve. The problem occurs after sitting for an extended period of time (all I can guess is with the portable tank, we did not wait long enough for the problem to occur, therefore it was thought to have fixed the problem. I am sooooo thankful to all who have responded and helped, I can not imagine how much this would have cost for a mechanic to trouble shoot on an hourly basis. I have seen several post where people went to three different mechanics. I am truly thankful to Rodbolt17 for his help and guidance.

[99yam40]

So, apparently you have not monitored the pressures while the problem shows it's head if you just think it is

I still believe you have not tested pressures while problem was there and you do not respond to my posts

[dorado42]

So YES 99YAM40 I did answer your question about PSI being 40 all the time... your assumption that I did not test while the problem occurred is incorrect if you would read ALL the post (that question did not need to be answered because it was answered in my earlier post.) After testing the motor with a pressure gauge it appeared the portable tank fixed the problem therefore I have not ran boat with pressure gauge again. I chased the fuel restriction problem to the point the entire fuel system is new (fuel lines, hose clamps, racors filter and bracket, low pressure pump and new filter in engine element. I chased the vacum on the motor through each part of the fuel system trying to isolate a vacum issue...none was found. The problem is sporatic and sometimes it occurs after sitting for 15 minutes, sometimes it occurs after sitting 30 minutes. I apologize if the problem is complicated, but I have truly done my best to express the problem and am VERY THANKFUL for everyone's input and truly sorry you feel like I was ignoring you, that was not my intention. The problem is sporatic so I do not run a pressure gauge on the motor all the time to check each time the problem occurs...you have NOT offered any thing for me to check, you simply just ask questions based on part of a comment that was removed from the entire post.

[dorado42]

99yam40....I did test the engine when the problem occurred with a pressure gauge. The problem fixed itself with a portable tank (pressure gauge attached) so therefore it was determined that is was a supply issue not a motor issue. The problem continued afterwards, I guess it was coincedence the problem did not occur with the portable tank as the problem is sporatic. No hard feelings I hope!!

[99yam40]

Sorry but I did not see where you made a statement that the pressures did not drop when problem happened.

As long as the rail has the proper amount of fuel pressure the injectors should dump the proper amount into the cylinders.

I do not see how the motor could be running out of the proper amount of fuel to the cylinders if the rail fuel pressure is staying in spec. unless the injectors are not firing properly or the screens are plugging and not letting the proper amount through them

Maybe it is just my opinion but
If lift pump can not keep up due to restriction, sucking air, or does not run when it should then the level in VST could drop and rail pressure would drop when it got too low

If check valve leaks and air is sucked in like Rodbolt says, the level in VST should drop and rail pressure would drop when it got too low to supply liquid fuel to the pump.

So seems like pressure should show when it runs out of fuel

Or is it possible to have rail pressure in spec but full of foam instead of liquid fuel?
That is one thing I did not think was possible

[madharchod]

you say your rail pressure is 40 and did not dropped at WOT then you should be looking at pick up problems or air being sucked in some place ,trace it through and you will find ,maybe your clams or zip tie loose which causes this,simple problem while people like MITCH make it sound terrifying

[rolrandy]

New to the fourm but have been reading quite alot on it.

Have an issue just like this thread have a few questions
1977 21 mako had a 1994 200 carb yami ran fine for 5 years unlil it tossed a rod or valve wasn't worth fixing had been rebuilt once already

purchaced a rebuilt 1999 200 OX66 hung it on the boat and have been fighting issues like the ones in this thread for the last 3 months.

many trips back to the place where I bought the motor still not fixed.
everything changed lift pumps, hp pump, regulator all fuel lines
fuel tank was replaced 5 years ago

seems to be an intermittent issue but when it starts stalling it in continous every minute or 2

one constant it runs fine for an hour or so when is is first out for the day

seems like an issue when it gets warmed up

any thoughts

[rodbolt17]

suggestion 1, post a NEW thread and your engine MODEL number.
suggestion 2, see suggestion 1.

the fuel systems are so vastly different,yet similar, that you cannot do the F225 and an OX66 systems on the same thread.

[dorado42]

Ok....so replaced the check valve before low pressure fuel pump......went out today and motor with new valve had to pump primer ball 20+ times....the other motor only 3-4 times for primer ball to get hard.....why would one primer ball take 20+ times to get hard....new primer ball also....

[rodbolt17]

would depend on the amount of air in the fuel system downstream of the primer or if the primer was sucking air.

its a PRIMER.
once the system is filled its no longer needed.

[mitch]

What was the orientation of the primer bulb arrow up ? or arrow side ways ?

[dorado42]

BOTH balls were orientated with the arrow sideways....but one ball took 20+ times to get firm....the other motor only 3-4 times....just wondering why such a difference

[seahorse5]

Hold the primer ball vertical - arrow up - and see if it takes fewer squeezes. If not, then you either have air in the system or a faulty primer ball.