tilt trim on a 1976 johnson 115 hp

[timberwolf 135]

hi all
i have a 1976 115el76 johnson outboard on a 76 searay srv180 i just picked this boat up and i have a trim question the motor has a omc trim and tilt kit on it kit #172859 my question is this when under power i cant trim the motor and if i trim it at idle the motor goes down as soon as i throttle it up is this the way it should work or should it stay trimed it also had a few ounses of hydraulic jack oil added to it is this type oil ok to use in the system
thanks bill

 

[RRitt]

Re: tilt trim on a 1976 johnson 115 hp

This is almost always the valve body. Sometimes water gets in the system and rusts out the bypass valves in your ram. Sometimes somebody adds ATF with additives and the orings get ruined with time. But these are rare. In 98 out of 100 boats it is the valve body.

The key question is if you have a Calco or Prestolite pump. The calco is perfectly smooth and round. The prestolite has four fins. The Calco pump is recessed into the resevoir. The prestolite pump has four mounting ears that line up with the four fins. The Calco isn't worth fixing. The Prestolite is.

If you have a calco, then take a moment to verify good rams. Fully lift and brace the engine. Unscrew the line that feeds into bottom of rams. PLug it up using fitting from NAPA. Remove bracing. Go eat lunch. When you come back from lunch engine will be either still raised or drifted down. If raised then rams are good. If down then rams are bad.

IF - your rams are good and you have a prestolite pump then you can get it rebuilt in the $130 range or replaced in the $400 range.

IF - your rams are good and you have a Calco pump then P/M me. I am in process of making an adapter so that Calco owners can swap out old stinky Calco for new shiny Volvo in the $250 range (including both motor and pump). I need a guinea pig to work with me on stuff like mounting bolt lengths and hydraulic tee's.

 

[ezeke]

Re: tilt trim on a 1976 johnson 115 hp

hi all
i have a 1976 115el76 johnson outboard on a 76 searay srv180 i just picked this boat up and i have a trim question the motor has a omc trim and tilt kit on it kit #172859 my question is this when under power i cant trim the motor and if i trim it at idle the motor goes down as soon as i throttle it up is this the way it should work or should it stay trimed it also had a few ounses of hydraulic jack oil added to it is this type oil ok to use in the system
thanks bill

If you don't use the OMC/BRP fluid, use GM Dextron ATF.

If there is air in the system, it will not hold. Make sure that the manual release is tightened to specifications in the service manual.

 

[RRitt]

Re: tilt trim on a 1976 johnson 115 hp

If you don't use the OMC/BRP fluid, use GM Dextron ATF.

If there is air in the system, it will not hold. Make sure that the manual release is tightened to specifications in the service manual.

LOL. Unless you completely rebuild the system. Then go ahead and use the good stuff (industrial hydraulic oils).

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

hi
ok so it is the prestolite pump i am going to try to figure out what thread the small silver line is and test the rams right know the motor has been up for two days and has not dropped and with all my weight on it it seems to hold me but i will still do the ram test
thanks bill

 

[RRitt]

Re: tilt trim on a 1976 johnson 115 hp

no need to test the ram. If system hold for two days then ram is good.

maybe you don't have power trim? just power tilt? find other post on similar subject. it has pictures.

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

ok so i just read the install instructions they say this kit provides
for remote controlled trimming of a boat at full power to compensate for most boat loading conditions motor trim angle can be adjusted up to 15 deg. beyond 15 deg. this unit operates as a full power tilt if i read this right it is only lifts the motor from the all the way down and will only lift it 15 deg up

 

[RRitt]

Re: tilt trim on a 1976 johnson 115 hp

parts of your information are self-conflicting or confusing to me. please post pictures.

 

[ezeke]

Re: tilt trim on a 1976 johnson 115 hp

Trim range is 15 degrees, the tilt is around 60 degrees. In the first 15 degrees of travel, both cylinders are employed, resulting in sufficient power to overcome full engine thrust. After that only the tilt cylinder is employed, so that while faster, the mechanical advantage is reduced. The motor will have to be running at low RPM to raise beyond 15 degrees.

Click the thumbnails for the flow diagrams.

If either cylinder is not working or is working poorly, the mechanical advantage will be considerably reduced.

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

hope this works

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

can i buy a replacement motor for this pump

 

[ezeke]

Re: tilt trim on a 1976 johnson 115 hp

Depends on which pump you have. The pump in your installation instructions is a Prestolite and that one is readily available. Search "Arco 6208".

 

[RRitt]

Re: tilt trim on a 1976 johnson 115 hp

hi
ok so it is the prestolite pump i am going to try to figure out what thread the small silver line is and test the rams right know the motor has been up for two days and has not dropped and with all my weight on it it seems to hold me but i will still do the ram test
thanks bill

hi all
i have a 1976 115el76 johnson outboard on a 76 searay srv180 i just picked this boat up and i have a trim question the motor has a omc trim and tilt kit on it kit #172859 my question is this when under power i cant trim the motor and if i trim it at idle the motor goes down as soon as i throttle it up is this the way it should work or should it stay trimed it also had a few ounses of hydraulic jack oil added to it is this type oil ok to use in the system
thanks bill

I don't think you need a trim motor. The first quote is a fairly good acid test that your system is working perfectly.

The problem is your initial post (second quote). If the engine is beyond the trim then your prop should be almost out of the water and you should not be able to get enough power to push it down unless there is a defect in valve body or cylinder piston. The only way a fully functional system should be able to lower a spinning prop into the water is if you have power tilt. But that is a completely different system than the installation sheet scan that you posted.

I think you should read the instructions very carefully and make sure everything is properly installed and connected. If you buy anything, a manual with section on trim/tilt would be good. You can get original factory service manuals off ebay for cheap. They will give you more specific info than a generic.

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

you guys are a great help i am looking repair book next i need to figure out what prop is on it it the one that came with the boat is damaged and has no markings on it for pitch i know it is 13" dia. on a 1976 115 johnson the boat is a 1976 16.5 searay srv180 closed bow the damaged on moves the boat 32 mph any one have a good starting point

 

[ezeke]

Re: tilt trim on a 1976 johnson 115 hp

The 1976 115 motors were shipped with a 13-1/4 X 17 aluminum 3 blade prop. #0382764. That propeller supersedes to BRP #0765183 with the same dimensional specifications.

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

i will start their and check the rpm but i am hopeing to get more than 30 mph from this boat

 

[ezeke]

Re: tilt trim on a 1976 johnson 115 hp

i will start their and check the rpm but i am hopeing to get more than 30 mph from this boat

You should use a pitch that will allow you to reach 5800 RPM with your average load at WOT.

A 17 pitch prop on your gearcase has a maximum theoretical speed of 44 MPH at 5500 RPM. With 10% slip, the speed would be 40 MPH.

Use 2.0 for gear ratio: http://go-fast.com/Prop_Slip_Calculator.htm

 

[timberwolf 135]

Re: tilt trim on a 1976 johnson 115 hp

So 5800 rpm is where i need to be i feel 40 is a good speed for that boat i think i will buy a 17 pitch and see how it runs but if the boat runs over 5800 rpm is it best to go up in pitch size no matter the boat speed for the most part only 2 people will be in the boat at one time and some fishing gear