Can Larson Senza be fixed?

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SankorLiu

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My friend has a 88 larson senza boat. The motor doesn't run, won't crank over but will turn over by hand. It has a 350 mercruser v8 through hull exhaust.

How can I test the pressure of cylinder? How can I test the starter? Is it easy to fix the motor?

Thank you
 

Bt Doctur

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If your turning the motor please STOP before you break the bolt.
Battery connection clean and tight at the battery, the starter and the neg ground at the block.
Locate the slave and jump the yellow/red and red/ purple. If the connections and starter are good, motor should spin
 

Bondo

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My friend has a 88 larson senza boat. The motor doesn't run, won't crank over but will turn over by hand. It has a 350 mercruser v8 through hull exhaust.

How can I test the pressure of cylinder? How can I test the starter? Is it easy to fix the motor?

Thank you
Ayuh,..... Is the battery fully charged,..??
Is it wired correctly,..??
Pull the starter, 'n bench test it,.....

You've gotta fix the starter, before you can run a compression test,....

The motor is easy enough to fix, depending on how much "Boat" the builder put in the way,.....
 

SankorLiu

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Ayuh,..... Is the battery fully charged,..??
Is it wired correctly,..??
Pull the starter, 'n bench test it,.....

You've gotta fix the starter, before you can run a compression test,....

The motor is easy enough to fix, depending on how much "Boat" the builder put in the way,.....
Thank Bondo
 

SankorLiu

Cadet
Joined
May 11, 2022
Messages
24
If your turning the motor please STOP before you break the bolt.
Battery connection clean and tight at the battery, the starter and the neg ground at the block.
Locate the slave and jump the yellow/red and red/ purple. If the connections and starter are good, motor should spin
Thank Bt.
 

tank1949

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My friend has a 88 larson senza boat. The motor doesn't run, won't crank over but will turn over by hand. It has a 350 mercruser v8 through hull exhaust.

How can I test the pressure of cylinder? How can I test the starter? Is it easy to fix the motor?

Thank you
you should get distributor tool to prime oil before going any further!!!!!!!
 

tank1949

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Not maybe … yes done it many times. Please learn what you are talking about. will circ oil the same way with no load on internals.
If motors sat for several years, oil on bearings may have completely drained off or reduced. I would not take the chance, but everyone is different.
 

fatlenny

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No need to be aggressive commenting "Please learn what you are talking about." The point of turning the oil pump without rotating all the internals is just that, getting oil to the right places while not rotating the internals. I agree that pulling the plugs will lighten the load and work to an extent in my opinion but not help the dry bearings that are being turned before the oil gets there. (I recommend pulling the plugs as well, but to put a little oil down each cylinder before rotating. If you dont want to prime the oil pump I also recommend pulling the valve covers and pouring some oil over the valve train) Don't forget about the cam bearings and cam lobes. These areas need oil as well, this is where only turning the oil pump comes in play. Just because you "done it many times" don't make it the right way. Many professional engine mechanics will disagree with you including this hobby mechanic who has rebuilt a few of his own engines.
 

Scott06

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No need to be aggressive commenting "Please learn what you are talking about." The point of turning the oil pump without rotating all the internals is just that, getting oil to the right places while not rotating the internals. I agree that pulling the plugs will lighten the load and work to an extent in my opinion but not help the dry bearings that are being turned before the oil gets there. (I recommend pulling the plugs as well, but to put a little oil down each cylinder before rotating. If you dont want to prime the oil pump I also recommend pulling the valve covers and pouring some oil over the valve train) Don't forget about the cam bearings and cam lobes. These areas need oil as well, this is where only turning the oil pump comes in play. Just because you "done it many times" don't make it the right way. Many professional engine mechanics will disagree with you including this hobby mechanic who has rebuilt a few of his own engines.

Since you threw your hat in the ring, Maybe you should learn what you are talking about too…

if you want to do those things feel free, but spinning on starter will accomplish the same thing. In fact this was recommended by the engine supplier when i repowered my boat a few years back. I thought they would have required priming.

Pretty much everyone on here has rebuilt a few engines, trans, restored cars, hot rods etc , marine engines and out drives..
 
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fatlenny

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Since you threw your hat in the ring, Maybe you should learn what you are talking about too…

if you want to do those things feel free, but spinning on starter will accomplish the same thing. In fact this was recommended by the engine supplier when i repowered my boat a few years back. I thought they would have required priming.

Pretty much everyone on here has rebuilt a few engines, trans, restored cars, hot rods etc , marine engines and out drives..
Rolling eyes. I didn't say it wouldn't work to get it running, I am saying it is not the best advise. You can just crank an motor that has been sitting for a long time like you advise, but you risk scoring piston cylinders, bearings, and valve train parts. Sure, this wont instantly break anything but it will shorten its lifespan. You making comments that people dont know what they are talking about is not productive here, It was sound advise to prime the oil pump. You should be open to learn some things your self instead of saying others don't know what they are talking about. If lubrication is not important then why even have oil in your motor at all? I bet you think changing your break in oil is not necessary either.
 

Scott06

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If lubrication is not important then why even have oil in your motor at all? I bet you think changing your break in oil is not necessary either.
This sounds like some of the convos my teenager has ... thats shows a lot of experince...you better stop betting you cant afford it
 
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