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89 Baretta

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bobj

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"alright i have been reading t

"alright i have been reading the posts here for a better part of the evening and cannot find the answers that i am looking for, so i am left with a post.

You all seem to rather well informed on all of the advise that you give,

i just bought a 89 Baretta boat with a volvo engine (4cyl) aq 131 d, and a volvo sterndrive 275. the motor has a low compression reading on the #4 cylinder (50 psi) and the driveshaft bellow boot is ripped.

i have two questions, 1) how do you remove the outdrive/driveshaft to replace the boot?
2) what is the likely cause of low compression?

questions may be vague, but i am just starting to figure out what the problems are with my new find. and any help you can offer me would be greatly appreciated."
 
"Hi,

To remove the drivesha

"Hi,

To remove the driveshaft, the easiest way is to remove the upper gear assembly. Alternatively, you can remove the whole outdrive. Check this:

http://www.marineengine.com/discus/messages/12487/61601.shtml

http://www.marineengine.com/discus/messages/12487/24707.shtml


Just consider that if the bellows is ripped, water will have likely ruined the u-joint bearings and possivly the bellhousing bearing as well. In that case, you have a lot of work ahead of you.

The low compression can be due to leaks through valves or piston/piston rings. The best way to determine the source of the leak is to conduct a leakdown test. You can either purchase a leakdown tester or make your own. If you have never done that test, check these two links:

http://www.geocities.com/dsmgrrrl/FAQs/leakdown.htm

http://vmaxoutlaw.com/tech/leakdown_tester.htm

Also, you can just inject compressed air at about 40 psi on each cylinder after positioning the piston at TDC (end of compression) and listen where the leaks are (crankcase, intake or exhaust valves, etc)."
 
"i had intended on changing th

"i had intended on changing the u-joints while i had it apart, but how will i know if the "bell housing bearing" is bad? and is that the same as the gimbal bearing?
i was told that the engine would need be removed to repalce the gimbal bearing? true or false?"
 
"Bob, I suggest that when you

"Bob, I suggest that when you remove the u-joint check if there are any indications of moisture in the grease around the bellhousing (gimball) bearing. This, however, will not tell you for sure if the bearing is good or bad.

Indeed you need to pull the engine and the bellhousing to remove the bearing. The bad news is that if you don't replace the bearing and it is toasted, when it goes it may ruin the bellhousing as well, sometimes allowing the ingress of water inside the boat.

Since apparently you don't know the boat's history, if I was in your shoes, I would definitely replace the bellhousing bearing."
 
"first off thank you for your

"first off thank you for your help

secondly, seeing as how i am now apparently removing the engine, lol is there anything else that should be changed while i have it out?

lastly, how difficult is it to remove a engine and bellhousing in a boat? i am a mechanic by trade, but have yet to delve into the mysteries of the sea."
 
"Your engine is not too diffic

"Your engine is not too difficult to remove, but I suggest you first get hold of a copy of the Seloc or Clymer manuals. Briefly, once you free the clamping ring from the transom shield and loosen the front mounts, you can pull it. Of course, you first have to disconnect wiring and plumbing.

Once the engine is out, replace the little bearing at the end of the crankshaft guiding the primary shaft, as well as the bearing in the bellhousing and the two lip seals. Then, replace the u-joint bearings and you are set until Murphy decides to give you a hard time again.
biggrin.gif
"
 
"well i decided to work on the

"well i decided to work on the outdrive tonight for a little while, i got the driveshaft bellow boot unstrapped from the outdrive enought to peak inside, i noticed that the ujoints appear to be in really good, if not new condition, i will obviously see better when i get it apart. but to me this is a good sign that there is no water damage to the bearings.
lets say that when i get it apart and the joints move freely and there isnt rust as assumed there would be, is it safe to presume that the gimble bearing is good too?

Under normal conditions how would one know if that gimble bearing is bad or going bad? before it destroys things and the boat sinks??

also i dont notice any front mounts? where would they be and what would they be bolted to? (im going to assume at this point that maybe someone removed them?)"
 
"If the bellows is ripped and

"If the bellows is ripped and the boat has been in the water, it seems obvious that the u-joints have been exposed to water.

Under normal conditions, you should hear a bad bellhousing bearing "growling" before it decides to do very nasty things.

Some 4-cylinder Volvo engines do not have front mounts, and that's a bad idea. Consider installing them (see link):

http://www.marineengine.com/discus/messages/12487/21216.shtml"
 
"im not sure that the boat was

"im not sure that the boat was in the water with the ripped bellow. The bellow actually ripped from dryrot at the bellow point, so i dont know that it actually made it into the water in this condition.


so is it safe then if when i get it running and put it in the water, if i dont hear this noise that the bearing is good for now?"
 
"Bob, if after evaluating the

"Bob, if after evaluating the whole picture you decide it is safe not to replace the bearing, then it will be your gamble, not mine.
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"
 
thank you for your wisdom in t

thank you for your wisdom in these matters they have been ever so helpful

do they offer those mounts for the front of the engine for sale or would i have to favricate them?
 
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