96 ocean pro not idling

SBLGFD1

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Joined
Jul 6, 2009
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13
Looking for ideas and thoughts.
Running a pair of 1996 Ocean Pro 200?s on a Grady White Sailfish. It has been a long spring ? broken shaft and a blown power head ? see my previous post at ?
http://forums.iboats.com/showthread.php?t=330599&highlight=ocean+pro
I found a good running take off to replace my blown power head unit and am having some issues getting it to run properly . Here is what I have done so far :
To get the take off to match up I had to reinstall my counter rotating lower unit, transfer my VRO as they had disabled it on the take off, and replace the wiring harness with one off my other motor as this motors harness had a single large Red plug as opposed to individual plugs (OEM or aftermarket I don?t know).
The replacement motor would run but not well ? would not idle and would often die right off. I did a link and sync, and found much of the linkage to be quite loose and sloppy . So in doing the link and sync I replaced much of the linkage and it is much tighter. Now the motor wants to idle high and keep creeping up to around 1600+ RPM under no load, under load I have it set to 850. Under load the RPM continue to decrease from 850 over 60 seconds or so until it gets to about 350 ? 450 RPM?s and then dies. Motor runs great at higher RPM?s under load or no load, but when you bring the RPM?s down after running then shift to neutral the RPM?s run up to 2500-3000 or so with no load ? like its loaded up on fuel -
Other items ? as this is the first time this motor has run with a VRO, I batch mixed my aux tank so we are running a stronger Oil / Gas mix. I have changed the fuel filter ? 10 micron spin on. There is a in line glass filter in the engine cowling when watching this filter I can see fluctuations in the fuel flow ? air comes and goes ? seems to have no correlation to the way the engine is running. I will be trying to work the air out of that tonight. All the plugs are new and gaped appropriately.
Could the return system be not working? My understanding of this system is it returns excess fuel from the cylinders back to the intake manifold. I removed one of the return lines from the cylinder side while the unit was running and you can feel air pulses from the cylinder side and a mist of what appears to be fuel comes from the manifold side.
At a loss?.
I appreciate the wealth of knowledge here and that people are willing to share.
Thanks in advance- sorry about the length of the post.
SBLGFD
 

SBLGFD1

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Joined
Jul 6, 2009
Messages
13
Re: 96 ocean pro not idling

update - dont seem to have a air leak in the fuel system pre VRO. able to remove fuel line from VRO and run primer pump - builds and holds pressure.

SBLGFD1
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: 96 ocean pro not idling

Having a real hard time grasping the symptoms, I read it 5 times then it dawned on me...

under no load the idle rpm creeps up to 3K

under load it drops down to 400 and quits.

offhand, just a wild guess....

if the counter rotating gear box has a slight bind or drag it will cause the idle to sag and quit. If you set the idle to compensate for that drag then under no load it will run up too high. Or if its over-propped?
 

SBLGFD1

Cadet
Joined
Jul 6, 2009
Messages
13
Re: 96 ocean pro not idling

Sorry about the confusion on the post -too much info.
But yes you have figured out what I am tring to say - no load idle RPM's go up, under load it stalls. Prop is what was on the previous unit that ate a piston and is also the same prop as is running on the standard rotation unit of the pair I hink these are the original OEM props.

Any way to tell if there is a bind or drag in the gear box?

Thanks / sorry
SBLGFD1
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: 96 ocean pro not idling

Drop the leg and check it manually , test the engine without the lower unit.
I tend to think it would overheat if that was the problem....

Before you do that, you say;

"shift to neutral the RPM?s run up to 2500-3000 or so with no load ? like its loaded up on fuel - "

Or over advanced ignition at idle.
make sure the timing roller is just touching the pickup cam at idle.
See these pics and look at yours. The manual is a bit vague on this,

http://bbcboards.zeroforum.com/zerothread/357667-throttle-roller-timing-arm-adjustment-60-motors

Could be the problem because acceleration from idle is controlled by the ignition advance first, then fuel. Fuel is constant metered by the idle circuit until the throttle pickup starts to transition thru midrange then the butterfly's open and fuel is passed thru the midrange jets....I think.
 

SBLGFD1

Cadet
Joined
Jul 6, 2009
Messages
13
Re: 96 ocean pro not idling

Thanks I will check it - when I did the link and sync I set it for 0.005 gap with a feeler gauge ( or what ever the manual said - I am at work now so this is all from memory) - seems like not much of a gap.
 
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