Brought the 75 home (started) - cleaning up nice
- Thread starter caveman
- Start date
steplift20
God
Caveman, she is go8ng to clean up very nice , the outside of the hull looks great. Get some bleach,soft scrub and toilet cleaner and go to work. If you have a power washer. Now is the time to use it.
You hav3 to show updates as you go along. Welcome to the site. Now your family
You hav3 to show updates as you go along. Welcome to the site. Now your family
Cleaned up good. Everything seems solid (transom, deck, etc). Hooked up a good batt from another project and she cranked over. Hydraulics were dry so I picked up some Quicksilver Power Steering and Trim fluid, topped her off and we were able to trim up to remove the support bracket from the top and trim down with help pushing (probably overfilled -relieved some fluid). I'm not sure if went all the way down. It was still at an angle a bit. Tried like hell to get it to budge a bit more but no go.
Got a fire extinguisher at the ready, hooked up my small external tank for my 4 stroke outboard, put her on the hose, and tried to crank. Would not fire. Removed flame arrestor from carb and primed but nothing. I did notice that starring fluid came out from under the carb mounting nuts when I sprayed it in...a lot. Might need a new gasket.
No luck starting but everything seems promising. I didn't see any gas coming from the portable tank into the carb. Maybe some blockage or too much leak/air.
Next step would be carb gasket (but I think it would fire or try if I'm priming with starting fluid) and check points/cables/plugs, yes?
Got a fire extinguisher at the ready, hooked up my small external tank for my 4 stroke outboard, put her on the hose, and tried to crank. Would not fire. Removed flame arrestor from carb and primed but nothing. I did notice that starring fluid came out from under the carb mounting nuts when I sprayed it in...a lot. Might need a new gasket.
No luck starting but everything seems promising. I didn't see any gas coming from the portable tank into the carb. Maybe some blockage or too much leak/air.
Next step would be carb gasket (but I think it would fire or try if I'm priming with starting fluid) and check points/cables/plugs, yes?
scook
God
It should kick over with carb primed, but with starting fluid leaking out, there’s a vacuum leak that won’t let it run. Sounds like you’re on the right track. I don’t recall if you got how important it is to replace the outdrive impeller and be sure there’s water running through the outdrive when you get it running. I made that mistake and suffered for it.
steplift20
God
Scook good advice. Wait for more advice from the heavy hitters.
The thing I would check is the fuel filters and fuel lines first
The thing I would check is the fuel filters and fuel lines first
scook
God
Right on Step. SpareParts recommended that to me ages ago when I was getting mine going, and said to buy the good USCG approved fuel line - itt lasts. Also, the fuel filter, which also catches water could be holding a fair amount of water.
Something else I haven’t noticed mentioned is the heat exchanger, if you have one. Pretty sure my setup is like what I see in the pictures - a Mercruiser 170. Mine has a heat exchanger that keeps the engine coolant separate from the raw water pumped in from the outdrive. If you have that and live where it gets cold in the winter, be SURE to take the plug out and drain it at the end of the season. That exchanger is expensive and a hard freeze if it’s full of water can destroy it- I think Mercury wanted around $1200 or more for it ten or fifteen years ago. Fortunately, I found out that they were, and maybe still are, manufactured by a company in the Pacific NW and got one for about half price. If you have that problem, let me know and I’ll try to find where you can buy one more directly.
Something else I haven’t noticed mentioned is the heat exchanger, if you have one. Pretty sure my setup is like what I see in the pictures - a Mercruiser 170. Mine has a heat exchanger that keeps the engine coolant separate from the raw water pumped in from the outdrive. If you have that and live where it gets cold in the winter, be SURE to take the plug out and drain it at the end of the season. That exchanger is expensive and a hard freeze if it’s full of water can destroy it- I think Mercury wanted around $1200 or more for it ten or fifteen years ago. Fortunately, I found out that they were, and maybe still are, manufactured by a company in the Pacific NW and got one for about half price. If you have that problem, let me know and I’ll try to find where you can buy one more directly.
spareparts
God
fix the vacuum leak, put a new set of points in and see if you are gettin an spark. Once you've determined the engine is good, Id invest in an electronic ignition conversion for it. Scook, his engine is the 250 cubic inch straight 6 chevy motor, your engine was the Mercruiser 224 cubic inch 4 cylinder, differnt engines
@spareparts - Thanks. I will definitely upgrade to Pertronix or similar once I determine if outdrive is good.
It's on a spare plastic tank with fresh-ish fuel. I picked up a couple of carb base gaskets and I was going to swap one out, but disassembly of the linkage, etc looks a little challenging. Maybe some of the parts just slip out, but I don't want to forget how it goes back together. After some more research I'm wondering if the starting fluid was running out through some kind of overflow. I didn't spray that much. Could the extra/overflow just been leaking out of the carb through an overflow of some sort. I did loosen the carb base nuts already a bit so going to have to move forward with replacing the gasket.
The start switch has been moved to the back near the motor. Just a push button. There is a vacuum gauge back there with a line from the carb. Check pics. I don't have a key currently (waiting on mail) so I guess it wasn't getting spark.
1) Should I drop some oil in the cyls before I crank it too much? I was watching an engine restoration vid last night (another Merc 165) and a guy used Marvel Mystery Oil for this purpose.
2) In addition to the hard fuel line there is an another hard line (wrapped in heat shield) that goes straight down to manifold on the stbd side of the carb. I loosened that fitting and the whole pipe came off from the manifold - looked like something might have broken - there is a small stand off left in place - not sure how it mates/mounts up. Looks to be coming off the choke. What is this for and will it affect vacuum?
3) Before I get any further Im going to vacuum/clean off the engine (no washing yet). I don't want anything falling off down in any holes left by things like #2 above.
4) There is also the vacuum line to the gauge sitting above the engine. I suppose this could be dry-rotted. Should I replace that? I don't even know if the gauge is good anymore.
5) Can I short the key "on" switch to get power back to the coil?
The bad (potentially) - I lowered/trimmed down the drive leg and removed the oil plug. Some clear (very clear) water ran out (not white/milky but clean). Then some oil started draining very slowly and I put the plug back in. Is presence of water in there a definite sign that seals are bad? Could water have gotten in some other way of the years and settled in the bottom of the housing? Also maybe the drive is just empty and in need of refill.
It's on a spare plastic tank with fresh-ish fuel. I picked up a couple of carb base gaskets and I was going to swap one out, but disassembly of the linkage, etc looks a little challenging. Maybe some of the parts just slip out, but I don't want to forget how it goes back together. After some more research I'm wondering if the starting fluid was running out through some kind of overflow. I didn't spray that much. Could the extra/overflow just been leaking out of the carb through an overflow of some sort. I did loosen the carb base nuts already a bit so going to have to move forward with replacing the gasket.
The start switch has been moved to the back near the motor. Just a push button. There is a vacuum gauge back there with a line from the carb. Check pics. I don't have a key currently (waiting on mail) so I guess it wasn't getting spark.
1) Should I drop some oil in the cyls before I crank it too much? I was watching an engine restoration vid last night (another Merc 165) and a guy used Marvel Mystery Oil for this purpose.
2) In addition to the hard fuel line there is an another hard line (wrapped in heat shield) that goes straight down to manifold on the stbd side of the carb. I loosened that fitting and the whole pipe came off from the manifold - looked like something might have broken - there is a small stand off left in place - not sure how it mates/mounts up. Looks to be coming off the choke. What is this for and will it affect vacuum?
3) Before I get any further Im going to vacuum/clean off the engine (no washing yet). I don't want anything falling off down in any holes left by things like #2 above.
4) There is also the vacuum line to the gauge sitting above the engine. I suppose this could be dry-rotted. Should I replace that? I don't even know if the gauge is good anymore.
5) Can I short the key "on" switch to get power back to the coil?
The bad (potentially) - I lowered/trimmed down the drive leg and removed the oil plug. Some clear (very clear) water ran out (not white/milky but clean). Then some oil started draining very slowly and I put the plug back in. Is presence of water in there a definite sign that seals are bad? Could water have gotten in some other way of the years and settled in the bottom of the housing? Also maybe the drive is just empty and in need of refill.
Attachments
spareparts
God
heat shield wrapped line is for the choke, it draws heat from the manifold. Ditch the vacuum gauge and plug that hole. Odds are, you're going to need to rebuild that carb, they are pretty easy, so if the engine checks out, order a carb kit for it, it should come with a base gasket. Before you go spending a bunch of money, go ahead, pull the plugs and do a compression test. Red to yellow/red stripe will energize the starter, red to + on the coil will power up the ignition
No spark.
I tested the ignition switch and apparently it is in the "On" position. I tested 12.8 V between purple and red wires at the switch. I figured that should give power to the coil but there was nothing across the leads of the coil.
I added a wire directly from the battery + to the positive coil post (the one opposite of the distributor lead, right?) and nothing. I added a test light inline with a spark plug and no joy. With this configuration there was no voltage across the coil leads either.
Should I get another coil? Should I just fork out the $100 for the Pertronix electronic ignition?
I had pulled the carb off and put a new base gasket on it after cleaning the surfaces well. Torqued to specs. I'm guessing that the leaking was coming from vent tubes while I was dousing it with starting fluid the other day. Capped off the vacuum line that was going to the gauge.
Thanks for the advice!
I tested the ignition switch and apparently it is in the "On" position. I tested 12.8 V between purple and red wires at the switch. I figured that should give power to the coil but there was nothing across the leads of the coil.
I added a wire directly from the battery + to the positive coil post (the one opposite of the distributor lead, right?) and nothing. I added a test light inline with a spark plug and no joy. With this configuration there was no voltage across the coil leads either.
Should I get another coil? Should I just fork out the $100 for the Pertronix electronic ignition?
I had pulled the carb off and put a new base gasket on it after cleaning the surfaces well. Torqued to specs. I'm guessing that the leaking was coming from vent tubes while I was dousing it with starting fluid the other day. Capped off the vacuum line that was going to the gauge.
Thanks for the advice!
spareparts
God
clean the contacts on the points, use a little sandpaper and scrub the points, with power to them, they should spark when you spin teh motor over. You can see it with the cap off. You are applying reduced voltage to teh coil when the engine is running, when starting it gets full voltage from the starter solenoid. Dont leave full voltage on the coil for long periods of time, it will burn your points up. Try to get it to fire up and do the compression test before spending any big money on it.
I'm not getting any voltage at the coil + that I can tell (measuring at coil + to ground). I replaced the ignition switch so I know it's good - I can get the engine to turn over with the key now. I get continuity across the IGN and BAT on the ignition switch with the key off - it seems someone has bypassed it somewhere (maybe?), likely back near the engine, but I can't figure out where (maybe they lost the key and hotwired the boat at one time). Maybe the curly red wire jumping from the trim mechanism to the starter battery (see pic)? Hmmm... That actually goes from solenoid BAT terminal to whatever the thing is by the trim and then to the push button switch. Another black wire goes from solenoid Start to the push button for the cranking.
Im trying to figure out which wiring diagram to use (found a few online). The ones I see don't jive with my setup - either my harness has more wires, or the plug in the diagram doesn't match, colors are different, etc. I likely have an issue with the resistor wire (if I can find where it is) or maybe the shift interrupt switch? It looks pretty corroded up there. There is also some kind of small round/cylindrical relay or something mounted between the trim reservoir and the engine that has several wires going to/from it (maybe relay for trim?)
There are 3 purple wires coming the harness from the front of the boat to the back - one of which is broken. The plug comes apart pretty easily so I should be able to figure out which wire is which by tracing with multimeter.
I'll remove the coil and test resistance. I'm going to see if I can get the coil to spark with direct 12V. I'll open the distributor and see what condition things are in there and check points/clean up.
Im trying to figure out which wiring diagram to use (found a few online). The ones I see don't jive with my setup - either my harness has more wires, or the plug in the diagram doesn't match, colors are different, etc. I likely have an issue with the resistor wire (if I can find where it is) or maybe the shift interrupt switch? It looks pretty corroded up there. There is also some kind of small round/cylindrical relay or something mounted between the trim reservoir and the engine that has several wires going to/from it (maybe relay for trim?)
There are 3 purple wires coming the harness from the front of the boat to the back - one of which is broken. The plug comes apart pretty easily so I should be able to figure out which wire is which by tracing with multimeter.
I'll remove the coil and test resistance. I'm going to see if I can get the coil to spark with direct 12V. I'll open the distributor and see what condition things are in there and check points/clean up.
Attachments
spareparts
God
Going to take me a minute,been a while since I've used the old color codes, they were standardized in the early 80s. Tan wire is key on power. There's two wires at the coil because one wire is resisted voltage,the other bypasses the resistor and gets power from the solenoid on the starter when the starter is engaged. Remove the wire from the coil and check voltage with the key on. If you don't have voltage with the key on, you may have a bad resistor or wiring issues.what color wire is key on at the switch? Check the big round wiring harness plug,unplug it and check the connections. The red sguilgy wire is just the power wire to the trim motor. The thing on the engine you asked about is a slave solenoid, it's used because of voltage drop issues when long runs to the key switch. Basically two solenoids in series to engage the starter. Yellow wire is key starter engagement.
spareparts
God
Btw, you won't get full 12vokts to the coil key on
I was able to get it started (direct power to coil) and do a compression test. I have never done one before so not sure about results or method.
I am getting 0 Volts with key on at positive side of coil. Also took off the wire and measured directly with no voltage found. I re-checked while cranking with test light and saw some light. So I continued, bypassed points and got spark from coil after replacing coil wire (broke when I tried to pull it off - corroded - rigged and will need replacing).
Cleaned points and distributor - all which looked pretty good overall (points really needed cleaning though). I wasn't having any luck so I tried 12V direct to coil and it started trying to run... So I continued trying to start and it ran. I got a video of it the second time (lower unit is on hose) ...
It sounds terrible and the starter may even have remained cranking for some reason.
For compression I used my 5+ year old (still new in package) Harbor Freight tester. Hand tight in the plug holes (no oil applied to cylinders) and given 3-4 cranks (a few revs per crank) the numbers came out like this:
#1 - 103
#2 - 108
#3 - 125
#4 - 102
#5 - 105
#6 - 113
I need to figure out where the disconnect is from the ignition/key on to the coil. As Spare said I want to be careful with the points. If the compression sounds good for a first go I'll continue. What do you think of the compression numbers? Online I see a wide range of answers.
Broke a plug (way too easily) trying to get it out so I'll probably get new plugs and order a new coil wire (or a whole set). Change the oil (it seems really runny to me) with some SAE 30 and new filter. I might soak the cylinders in some oil overnight or two (I bought some Marvelous Mystery Oil for this purpose already).
The lower unit had been greased before I picked up the boat. I suppose the next thing would be to drain and fill the oil in lower unit. I'd like to determine if it is pumping water. Remove a hose?
Previously I had pulled the lower unit drain plug and @ few tablespoons of clear water came out. I couldn't remember if it was before or after I had first tried to start on the hose.
Questions:
Is the impeller moving any time the engine is rotating? For instance, during start. Anytime I crank the motor (even no start) should I be on the hose?
Where can I get the drain plug gaskets for the lower unit fill, vent, and trim unit? They all look same size. They are black plastic, flat ones.
Any tips on tracking down the issue from ignition power? I tried seeing if any of the plug tips had power when the key was on but didn't see anything there.
I don't seem to have a yellow resistor wire to the coil. Could I have an internally resisted coil that would be ok for 12V at coil? I see the two joined wires at the coil that are probably 12V + Run/ignition (NOT WORKING) and 12V + from solenoid.
Thanks!!
I am getting 0 Volts with key on at positive side of coil. Also took off the wire and measured directly with no voltage found. I re-checked while cranking with test light and saw some light. So I continued, bypassed points and got spark from coil after replacing coil wire (broke when I tried to pull it off - corroded - rigged and will need replacing).
Cleaned points and distributor - all which looked pretty good overall (points really needed cleaning though). I wasn't having any luck so I tried 12V direct to coil and it started trying to run... So I continued trying to start and it ran. I got a video of it the second time (lower unit is on hose) ...
It sounds terrible and the starter may even have remained cranking for some reason.
For compression I used my 5+ year old (still new in package) Harbor Freight tester. Hand tight in the plug holes (no oil applied to cylinders) and given 3-4 cranks (a few revs per crank) the numbers came out like this:
#1 - 103
#2 - 108
#3 - 125
#4 - 102
#5 - 105
#6 - 113
I need to figure out where the disconnect is from the ignition/key on to the coil. As Spare said I want to be careful with the points. If the compression sounds good for a first go I'll continue. What do you think of the compression numbers? Online I see a wide range of answers.
Broke a plug (way too easily) trying to get it out so I'll probably get new plugs and order a new coil wire (or a whole set). Change the oil (it seems really runny to me) with some SAE 30 and new filter. I might soak the cylinders in some oil overnight or two (I bought some Marvelous Mystery Oil for this purpose already).
The lower unit had been greased before I picked up the boat. I suppose the next thing would be to drain and fill the oil in lower unit. I'd like to determine if it is pumping water. Remove a hose?
Previously I had pulled the lower unit drain plug and @ few tablespoons of clear water came out. I couldn't remember if it was before or after I had first tried to start on the hose.
Questions:
Is the impeller moving any time the engine is rotating? For instance, during start. Anytime I crank the motor (even no start) should I be on the hose?
Where can I get the drain plug gaskets for the lower unit fill, vent, and trim unit? They all look same size. They are black plastic, flat ones.
Any tips on tracking down the issue from ignition power? I tried seeing if any of the plug tips had power when the key was on but didn't see anything there.
I don't seem to have a yellow resistor wire to the coil. Could I have an internally resisted coil that would be ok for 12V at coil? I see the two joined wires at the coil that are probably 12V + Run/ignition (NOT WORKING) and 12V + from solenoid.
Thanks!!
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spareparts
God
Impeller mives anytime the engine is spinning over. The two tan wires on the positive side of the coil,one supplies reduced voltage during normal operation, the other supplies full voltage during starting from the R terminal on the starter solenoid. The reduced voltage is supplied by key on voltage either going thru an external resistor(white porcelain thing mounted near the back of the head) or thru a resistor wire in the harness.double check your key switch wiring for key on power. Pull the wrap off the harness ,check for power thru the big cannon plug,if you have the external.resistor,check for power going in. Before you get too dep,let's revist those compression numbers,they are on the low side,normally 120 is what that motor shpuld make.did you take those readings after you had it running?
I had it running for a few seconds and then a while later I took those compression readings cranking a few rev, 3-4 times. The starter does stay engaged until I turn key "off" (engine will stay running until I disconnect 12V direct to coil).
I'm going to do an oil change (oil looks really thin - maybe years ago someone had dumped some seafoam or something in), and add lube to the drive (I think that is the other sound I'm hearing - dry gimbal or somewhere else in drive).
Engine seems to run smooth. This inline 6 is really quiet! Revs ok (throttle stiff - need to free up linkage). I can rev without engaging - neutral switch on throttle controls seems to work.
I'll try to trace wires first to see what I can find. Maybe the 12V straight to Coil is causing the solenoid to stay engaged since coil is connected to solenoid?
I'm going to do an oil change (oil looks really thin - maybe years ago someone had dumped some seafoam or something in), and add lube to the drive (I think that is the other sound I'm hearing - dry gimbal or somewhere else in drive).
Engine seems to run smooth. This inline 6 is really quiet! Revs ok (throttle stiff - need to free up linkage). I can rev without engaging - neutral switch on throttle controls seems to work.
I'll try to trace wires first to see what I can find. Maybe the 12V straight to Coil is causing the solenoid to stay engaged since coil is connected to solenoid?
steplift20
God
Whoa spare, I wish I knew what you were taking about. I wish I had 1/3 your knowledge. Move to New Jersey. Please. Do you know I can’t find a good marine mechanic.