Start up issues with a Frankenstein 86 Mercruiser 3.0

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Aug 2, 2021
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Bought a 92 Capri 10th Anniversary for $400. Upholstery great, glass is great, trailer great. The bilge / engine compartment was a mess of black and funky. Cleaned it up and did most all of what I thought was needed. Marvel in the cylinders, replaced the starter, alternator, cap, wires and plugs. New carb as the throttle shaft was seized. (If I were more skilled I would have rebuilt it)
Got it to rotate with just a screwdriver on the fly wheel. "Fxed" the leak that was "coming from under the the exhaust manifold" with a new manifold gasket. Got it together that night and ran it 10 minutes with great temp and oil pressure on the the muffs. Lemons into Lemonade!
The next day discovered all the black water in the ski locker bilge. Haha!..Just like you all knew... Big "smile" on the side of the block.
Found a long block from a reputable shop. The mechanic asked questions and asked for a pic of the exhaust manifold and matched the head to my existing manifold on an 86 block. Made the 6 hour round trip to Rose Oregon and dropped it in the next day.
The old set up that ran, and always wanted to run, had short plugs, new NGK BP6EFS's, if I have that right. Talked with the mechanic I bought the new engine from and he recommended the new one get Autolite 140 plugs, as it has the deeper reach. I moved everything from the old set up over to the new long block. Have tried and tried to get it to fire up. Positive I have TDC and the rotor set up on 1 with 1342. New battery that I keep on a tender and still just puff, puff puff... No Pop, Pop, Pop and no sign of starting. Spark confirmed on 1 and 4. Gas at least up to the new carb. Could I have a low spark issue with the old ignition coil? Maybe wrong plug or wrong gap at .045? Little smoke out the carb. I pulled the plugs and cleaned them twice as they looked wet and a bit blackened.
Any thoughts or things to try?
Thanks in Advance! iBoats and the Youtube have already been fantastic resources on my learnin journey.
 
Joined
Aug 2, 2021
Messages
11
Bought a 92 Capri 10th Anniversary for $400. Upholstery great, glass is great, trailer great. The bilge / engine compartment was a mess of black and funky. Cleaned it up and did most all of what I thought was needed. Marvel in the cylinders, replaced the starter, alternator, cap, wires and plugs. New carb as the throttle shaft was seized. (If I were more skilled I would have rebuilt it)
Got it to rotate with just a screwdriver on the fly wheel. "Fxed" the leak that was "coming from under the the exhaust manifold" with a new manifold gasket. Got it together that night and ran it 10 minutes with great temp and oil pressure on the the muffs. Lemons into Lemonade!
The next day discovered all the black water in the ski locker bilge. Haha!..Just like you all knew... Big "smile" on the side of the block.
Found a long block from a reputable shop. The mechanic asked questions and asked for a pic of the exhaust manifold and matched the head to my existing manifold on an 86 block. Made the 6 hour round trip to Rose Oregon and dropped it in the next day.
The old set up that ran, and always wanted to run, had short plugs, new NGK BP6EFS's, if I have that right. Talked with the mechanic I bought the new engine from and he recommended the new one get Autolite 140 plugs, as it has the deeper reach. I moved everything from the old set up over to the new long block. Have tried and tried to get it to fire up. Positive I have TDC and the rotor set up on 1 with 1342. New battery that I keep on a tender and still just puff, puff puff... No Pop, Pop, Pop and no sign of starting. Spark confirmed on 1 and 4. Gas at least up to the new carb. Could I have a low spark issue with the old ignition coil? Maybe wrong plug or wrong gap at .045? Little smoke out the carb. I pulled the plugs and cleaned them twice as they looked wet and a bit blackened.
Any thoughts or things to try?
Thanks in Advance! iBoats and the Youtube have already been fantastic resources on my learnin journey.
ps. dry cylinders pressure is at 150psi + or minus 1
 

GSPLures

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How are you confirming spark? With a tester you should have a bright blue spark?

Did you do a tune up? (Points, rotor, etc and set the dwell)

Are the valves properly adjusted?

Did you try putting the carb back to a base setting?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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you have an early motor in a late application the 3.0's changed in 1991

generally you try to keep the parts 1991 and later or 1990 and earlier
 

GSPLures

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you have an early motor in a late application the 3.0's changed in 1991

generally you try to keep the parts 1991 and later or 1990 and earlier
Not sure if the 91's were fuel injected (I am sure you have more knowledge on mercruisers than me) if it is could it be an electric fuel pump from the tank pushing fuel to a mechanical pump on the block and flooding the carb? The OP did state he had wet plugs
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Not sure if the 91's were fuel injected (I am sure you have more knowledge on mercruisers than me) if it is could it be an electric fuel pump from the tank pushing fuel to a mechanical pump on the block and flooding the carb? The OP did state he had wet plugs
the EFI variant came about 2010

first issue is the head and block are not same generation unless he also went with the older head.

most likely the dizzy is 180 out.
 
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Not sure if the 91's were fuel injected (I am sure you have more knowledge on mercruisers than me) if it is could it be an electric fuel pump from the tank pushing fuel to a mechanical pump on the block and flooding the carb? The OP did state he had wet plugs
You may be onto it. I had to put a new mechanical fuel pump on as the 86 block required the "upside down" fuel pump. The one I bought leaked like I sieve. I replaced it with an electric fuel pump that runs 4 to 7 psi. Though I did confirm it gets gas to the carb...it may be flooding.? I did smell the barrels and it does not look nor smell of gasoline. I will disconnect the fuel pump and try a squirt in the carb. I pulled the plugs yesterday, cleaned them and left the plug holes open to dry. The 92 had this same carb on it when it ran for a short time. Will give it another go.
 
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How are you confirming spark? With a tester you should have a bright blue spark?

Did you do a tune up? (Points, rotor, etc and set the dwell)

Are the valves properly adjusted?

Did you try putting the carb back to a base setting?
I pulled two plugs and set them against the block. Small orange spark, not nice big blue spark. I have a volt/ohm meter and will test the coil. I have a spark tester being delivered tomorrow. The kind with the adjustable gap that give an indication of magnitude of spark. I did replace the cap and rotor. I have not touched the valves. I did confirm TDC with cylinder pressure then double checked that #1 was at top using the patented chop stick down the plug hole. I confirmed the new plug wires were 1342 and all on tight. Even played with rotating the distributor a bit left and right of the #1 contact. I did a tiny adjustment to the idle screw on the new carb when getting the cracked engine running.
Thanks for the suggestions. Will keep at it.
 

GSPLures

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Orange is not good, but wait for the tester to confirm. If its still orange clean all of the connections and test you are getting proper voltage and ground. Also check for proper gap of the plugs. As stated by scott danforth make sure the distributor isnt 180 degrees off
 
Joined
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How are you confirming spark? With a tester you should have a bright blue spark?

Did you do a tune up? (Points, rotor, etc and set the dwell)

Are the valves properly adjusted?

Did you try putting the carb back to a base setting?
Orange is not good, but wait for the tester to confirm. If its still orange clean all of the connections and test you are getting proper voltage and ground. Also check for proper gap of the plugs. As stated by scott danforth make sure the distributor isnt 180 degrees off
I gapped the Autolite 140 plugs at .045, I will check them again. In terms of the distributor. With TDC confirmed by feeling #1 at the top and registration mark at 0 degrees on the gauge, The rotor should be pointed at the #1 spark plug contact correct? This is the way it is set up now. Is there anyway it could be 180 out with this info? I do know that the registration hits the 0 degree mark twice in a cycle, and confirmed I was at top. I will chase all of the connections and ground connections with wire wheel and wire brush as well. I tried to do a good job of cleaning contact points, but the thought occurred that the Ignition coil could have a bad ground to engine contact (if needed) with all the black spray paint that went on.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Yes, especially if you are using your finger to check. Sometimes its hard to tell between pfft and PFFFT

verify TDC of compression stroke. You may need to pull valve cover and verify rockers
 

GSPLures

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Are you positive you were on the compression stroke when you installed the distributor? Its easier to do with the valve cover off
 
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Yes, especially if you are using your finger to check. Sometimes its hard to tell between pfft and PFFFT

verify TDC of compression stroke. You may need to pull valve cover and verify rocker
Yes, especially if you are using your finger to check. Sometimes its hard to tell between pfft and PFFFT

verify TDC of compression stroke. You may need to pull valve cover and verify rockers
Is it possible that the rockers are set up wrong? I have super double verified that I am at TDC on compression. Piston at the top. Mark on 0 degrees. Used a chop stick and touched the top of the piston, and last night used my bore scope to confirm it. could even see my chop stick mark in the bit of oily residue on the top of the piston. I can pull the valve cover. What positions should I expect to see on the rockers at #1?
.
 

GSPLures

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Is it possible that the rockers are set up wrong? I have super double verified that I am at TDC on compression. Piston at the top. Mark on 0 degrees. Used a chop stick and touched the top of the piston, and last night used my bore scope to confirm it. could even see my chop stick mark in the bit of oily residue on the top of the piston. I can pull the valve cover. What positions should I expect to see on the rockers at #1?
.
should be closed if it is tdc on the compression stroke.

The rockers can be out of adjustment if thats what you mean by set up wrong. The proper adjustment should be 3/4 past zero lash. (Confirm with a manual) it will also show you the procedures for adjusting while running and while static.

I would confirm that you have the distributor correct first though.

The motor just needs compression, gas, and spark. (And proper timing) start with the timing and correcting the spark issue if they are still firing orange with the tester.

You said you bought a long block did you replace the head to match the exhaust? If so the valves need to be adjusted.
 
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Scott Danforth

Grumpy Vintage Moderator still playing with boats
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pull distributor, turn motor 1 full turn (1/2 turn on cam) re-install distributor and try
 
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pull distributor, turn motor 1 full turn (1/2 turn on cam) re-install distributor and try
You and GSPLures were right on. Got it running smooth as butter. My total novice lack of understanding. I was using a screw-in pressure gauge with a max stop and purge on it. tick the starter and watch it go up up up till it hit 150 and then feel for the top of the piston. Thank You Both!; and anyone else who was interested and rooting for me. Today was the first time ever timing an engine and it was very rewarding. I will hit the water tomorrow and let you all know how it goes.
 

GSPLures

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Glad to hear. Bring some basic tools with you as you may need to make some adjustments on the carb, shift cables etc.
 
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