GLSTA 115 Low rpm idle

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190Marco

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I purchased a new rebuilt engine by OBR, have done the 10 hour break in. Engine runs fine BUT, it will not hold idle unless I accelerate engine. Once I put engine on 1000 rpm, it will run smooth, but as soon as I pull back on neutral accelerating, engine will drop to 500 rpm and die.
Engine runs fine thru all the RPM, just idles at around 500 RPM and shuts off. I figured out that carbs don't really respond to adjustment and when covering starboard carbs 1 and 3 engine will shut off, If I do the same to port side 2 and 4 basically no change engine will not shut down.

Checked compression perfect 130-140 on all cylinders
Checked carbs back blow, No black blow
Rebuild carbs, no change
Replaced engine module with CDI, No change

Any clues?

Thanks
Nic
 
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saltchuckmatt

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Do a cylinder test ....(Pull plug wires while running) Sounds like 2 cylinders are down....test to confirm. (Wet plugs electrical, dry plugs fuel)

Report back and people can tell you what to do next.
 
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190Marco

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saltchuckmatt said:
Do a cylinder test ....(Pull plug wires while running) Sounds like 2 cylinders are down....test to confirm. (Wet plugs electrical, dry plugs fuel)

Report back and people can tell you what to do next.
Click to expand...
I have done that as well, when I pull wire on Cylinders 1 & 3 engine almost quits, when I do the same on 2 & 4 one can tell a difference, but not very strong like the other side and its not enough to die out engine.

Did want to mention, Pickup sensor, cables, ignition module are also new, I actually did this before rebuilding the carbs.

It just seems to me that the port side of the engine just has too much fuel, which it cant burn at such low rpm
 
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saltchuckmatt

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Ignition coils and power packs are aftermarket?

I would do a spark jump test....

Could you have messed up the carbs?
 
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190Marco

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saltchuckmatt said:
Ignition coils and power packs are aftermarket?

I would do a spark jump test....

Could you have messed up the carbs?
Click to expand...
Coils are OEM, Power pack is CDI, will do a Spark jump test. How much jump should I look for?

Don't think I messed up the carbs, used oem kits, and engine runs exactly the same as before with the issue on those 2 cylinder's. IS there a possibility this engine has a internal crack or so even though it has perfect compression?
 
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racerone

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Contact the seller of the rebuilt unit.-----And what went wrong with your old engine ???----Did you determine the cause of the issue ??----Carburetor float bowls checked for warpage ?----Is the high speed jet in place on each carburetor bowl ??
 
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190Marco

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racerone said:
Contact the seller of the rebuilt unit.-----And what went wrong with your old engine ???----Did you determine the cause of the issue ??----Carburetor float bowls checked for warpage ?----Is the high speed jet in place on each carburetor bowl ??
Click to expand...
Have not contacted seller yet as I don't know what to tell them because don't know what's going on. Original engine went underwater. Carb bowl not warped, and High speed jet in place
 
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racerone

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From post #1 I would say you have a carburetor issue in #2 & 4----And stop running this engine till you determine the issue !-----How did this motor run for you last year ?
 
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racerone

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Look into issues with #2 & 4 carburetors.-----Do not run this motor until you find the issue.-----Item #15 in place ?
 
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190Marco

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saltchuckmatt said:
7/16.....nice blue spark.
Click to expand...
Think I got it figured out, will need to put in water and run boat for a while. Spark was good on all 4 cylinders. What I did, was I closed the carb needle all the way and just waited to see what happens, after approximate 1 minute engine started to stall, so I opened it 2.5 turns, and started to get a relatively good idle. Issue was, I had set the carbs at 5.75 initial turns as manual stated, and never saw a change because change took about 1 minute to appear. Got it up to 900 rpm, and will rest in water now and run for a while to clean all the fuel out of engine. Thanks for your help, Will post back next week to see how all went
 
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saltchuckmatt

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If your out that far from spec then something is still wrong.

Are your settings different from one side of the engine compared to the other side?
 
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