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Message |
    
salty
New member
Username: salty
Post Number: 1
Registered: 06-2015
| | Posted on Tuesday, June 16, 2015 - 03:55 pm: | 
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I have rebuilt an MD2b. Upon initial startup I had problems getting oil suction to the pump. I replaced an oil tube assembly that used an O-ring seal with one that used a washer type seal.I also tried to squirt some oil into the oil pump passage and was able to get suction and hence oil pressure.I ran the engine many times over a 4-5 day period and always had oil pressure. Since then the engine has sat reinstalled in the boat for a couple of months and had its oil changed.I have tried turning it over on its starter motor and can't get oil pressure.I've tried making a nice thick annealed copper seal ring and tightening it in as hard as I can but nothing. Any suggestions? |
matt_morehouse
Senior Member
Username: matt_morehouse
Post Number: 155
Registered: 12-2009
| | Posted on Tuesday, June 16, 2015 - 06:11 pm: |
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Starter motor might not do it. Start it and see what happens.
Is it a mechanical gauge? |
salty
New member
Username: salty
Post Number: 2
Registered: 06-2015
| | Posted on Tuesday, June 16, 2015 - 09:33 pm: |
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Its mechanical. but I've also had the connection loose and no oil spills out.
Should it be run if there is no oil pressure? |
matt_morehouse
Senior Member
Username: matt_morehouse
Post Number: 156
Registered: 12-2009
| | Posted on Wednesday, June 17, 2015 - 12:02 am: |
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Yes, you can run it for maybe 30-60 seconds. If no oil pressure kill it.
A few more questions:
1. You said it had OP after the rebuild. How long did you run it and what was the OP?
2. Who rebuilt it? You or someone else?
3. Why was the rebuild necessary?
4. Was it a top end only rebuild or a top and bottom job?
Answer these questions and I can give you a good idea of what the problem is. |
salty
New member
Username: salty
Post Number: 3
Registered: 06-2015
| | Posted on Wednesday, June 17, 2015 - 12:58 am: |
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Yes, after I got it running it was around 40-50 psi, Over a period of a few days I probably put 10 hours on it. I rebuilt it because it was completely worn out.
I'm starting to suspect the oil pump is a bit edgey. Is it possible to remove it without pulling the flywheel? |
matt_morehouse
Senior Member
Username: matt_morehouse
Post Number: 157
Registered: 12-2009
| | Posted on Wednesday, June 17, 2015 - 09:56 am: |
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No, you have to pull the flywheel which is not a big deal.
It is unlikely the oil pump is the problem. When you rebuilt the engine did you dissemble and clean the pump?
Did you rebuild the bottom end?
40-50lbs is on the high end. What did it settle at when up to heat? Should be around 20lbs.
I know this sounds stupid but is there oil in the engine? Also just for kicks change the oil filter. |
salty
Member
Username: salty
Post Number: 4
Registered: 06-2015
| | Posted on Wednesday, June 17, 2015 - 08:52 pm: |
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Success. I now have oil pressure. I pulled the oil pump, was able to get it off without pulling the flywheel. I remembered when I was installing it I didn't like the amount of gear backlash but reasoned it would be ok. Well I checked the backlash and it was 0.018in. which is plus 4 over spec. I had 2 spare pumps which are slightly different from each other but one had gears that match and were within spec so I used those gears and it seemed to solve the problem.
Are far as oil pressure, I have a temporary guage on there now whose needle rests at 20psi and goes to about 60 at fast idle so an accurate reading isn't available right now. The bottom end is rebuilt and the bearing clearances are a little on the tight side |
matt_morehouse
Senior Member
Username: matt_morehouse
Post Number: 158
Registered: 12-2009
| | Posted on Wednesday, June 17, 2015 - 09:32 pm: |
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Good on you. |
