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I have a 1989 sea sprite and havent had any spark from the igniton coil from my 3.0L Mercruiser engine. I just removed the gray wire on the - terminal of the ignition coil and it started right up. It looks to me like this gray wire goes to the top of the engine. What does that mean and what do I need to replace to get this wire back connected and working? In reading some of the blogs it sounds like it is the tach wire but what do I replace and can I leave it disconnected until I get the replacement part and use the boat?
Optional Information: Make (of engine): mercruiser Model (of engine): mercruiser 3.0L Year: 1989 Horsepower: around 135 Already Tried: In diagnosing this problem I've Replaced the spark plugs, distributer cap, points and condenser, and ignition coil.
Hi my name isXXXXX will assist you..
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The gray wire is the signal wire for the tach. Replace the tach but disconnect the gray wire from the tach then reconnect the gray wire to the coil. This is to verify that the tach is the cause of the issue and not a shorted signal wire. Start the engine, if the engine doesn't start then the gray signal wire is shorted to ground. If the engine starts then replace the tach.
I disconnected the tach at the dashboard and reconnected it at the coil. The first time it sounded like it was going to start and then it wouldnt after that. The gray wire leaves the coil and is spliced and goes to the top of the engine and the other must go to the tach. What does it connect to on top of the engine and could that thing be the cause? Or is it the wire going up front to the tach?
The gray wire connects to the tach only. Did you disconnect the gray wire from the coil to see if it would start?
Yes, when it is disconnected from the coil it starts fine
Then the gray wire is shorted to ground somewhere between the tach and the coil. Check the connections at the main engine harness plug. Thats the large round plug at the rear of the motor. Then check the wiring at the dash. This wire should not be connected to anything between the coil and the tach. It would probably be easier to run a new wire if you can't find any bad connections or breaks in the wire.
Check the shift interrupt switch is in the neutral position. Disconnect the shift interrupt switch then connect the gray wire to both the tach and the coil. The gray wire connects to the white/green of the shift switch.
For some reason the gray wire is spliced when it leaves the coil and goes to what looks like a neutral switch on the top of the engine the other end goes in the wiring harness. Any idea why it is spliced and goes to the switch on the top of the engine?
Did you read my last post? If not here it is.
This is the switch you are calling a neutral switch. This switch grounds the ignition when shifting if the engine isn't in neutral or the middle of the lever the ignition is grounded. If the switch is in the vee notch of the lever then the switch is shorted.
OK. I just did that and with the wire disconnected from the shift switch it works fine. Therefore, its not the tach or the wire its the shift switch? Does that mean I need to replace the shift switch?
Is the drive in neutral? Move the lever back and forth to be sure the button of the switch is in the vee notch. If you have an ohm meter you can test the switch. Connect the test leads to the switch with the switch button not depressed you should have no continuity, with the button depressed you should have continuity. Now if you have continuity with the button not depressed the switch is bad. The button of the switch should be in the notch of the lever in the diagram if it is the switch is bad.
Sorry for the long delay in my response but the wife and kids were so excited that the motor was running we took it out on the lake. That's the good news. The bad news is it started but wouldnt go forward or backward. Could that be associated with this switch. Or, did I not align the gears properly when I replaced the impeller? I also just checked the contunity on that switch and everytime but once I had an open. I only had continuity once with the button pressed. All other times it was an open. Is that a problem with the switch or the drive handle?
Did your start issue start after doing the water pump? If yes remove the drive and get the shift straightened out thenj check the engine start issue. This might be just a simple case of the shift being misaligned causing the interrupt switch to activate causing no start.
That the shift misaligned on the shift rod shaft. The drive needs to be in forward and thew control needs to be in forward when you install the drive. The switch should have no continuity when the button is not depressed. Depressed continuity.Continuity grounds the ignition system no spark.
Yes, all my starting issues arrose after the water pump replacement. But, I did have the drive in forward when I replaced it. What do you mean the control in forward? So, I will put the gear in forward, drop the lower drive again, and reinert it. Any tricks for making sure it is aligned next time?
Both the drive and the shift control must be in forward gear. When putting the drive on hold pressure on the prop rotating to the left. This will keep the drive in gear. Be sure the splines align. Then put one nut on to hold the drive then check shift. If it doesn't shift right you only have to remove one nut.
When you say both drive and shift control must be in forward do I do that with just the forward drive handle?
And, how do I check the drive shift with the one nut on?
If you are removing just the lower portion of the drive the lower drive has to be in the same gear as the shifter in the boat. The one nut is to hold the drive on so you can check the shift. This is so if you miss the shift again you don't have to remove 7 nuts and bolts. The 1 nut is just easier than 7
Ok. I'm just not sure how I get the lower drive in the same gear?
I got the nut issue, but how do I check it after I have the one nut on?
Before you put the lower on rotate the shift shaft # XXXXX till you get neutral. Hard over Clockwise is forward then back about 1/4 turn is neutral then hard counter clockwise is reverse. You want the lower in what ever gear the shift handle in the boat is in.
Thank you. You have been extremely helpful. I might be back tomorrow after I give this a try.
Ok just let me know if you have anymore issues. Your welcome...........Thank you in advance..........Tan
Experience: 35 yrs. experience. I/O, Outboard & Inboard, Complete engine repairs.Certified Technician
I'm back... I removed the lower stern drive and realigned the gears and reinserted the drive. Seemed to go pretty well. I held pressure on the propeller to the left (drive in forward) and turned the gear shifter to the right. I never reconnected the safety switch. Took the boat on the water and all was good even pulled a kid on a wakeboard. Used if for a few hours. The next time I took it out after a couple hours I heard a clunk and the forward and reverse wouldnt work. Long way back paddleing. Do I just need to perform the same procedure for lowering the drive and reinserting? Did I do something wrong, or is this a different problem?
Check the shift on the lower and the upper to be sure the splines are still there. Reassemble
If the splines are still there, any idea why it fell out of gear? I want to make sure this doesnt happen again.
Not really but check all the linkage foe excessive play. Try shifting by hand before you remove the lower unit where the cable from the drive connects to the shift plate. If shift is ok their then possibly a control box or cable issue.
One other question. Do you know if the main drive spline from the lower unit to the upper unit requires an O-ring near the top of the spline? It has a groove like it requires one but one didnt come with the water pump kit.
Yes you need a o-ring it should have come with the kit. That o-ring keeps water out of the splines. Sometimes the old o-ring gets stuck in the seal.
I was going to remove the lower stern drive but before I did I put the control lever in forward and I couldnt turn the propeller to the left. I also put the control lever in reverse and I couldnt turn the propeller to the right. Based on this, I dont think it is the lower gear drive. So, I thought I must have missed something so I started it up and I could hear a little grinding. The engine reved up but the propeller didnt turn. Could it possibly be the main spline that goes from the lower unit to the upper? Or is there some type of clutch, or something else I should check?
There is a rubber coupler in the back of the engine that if it strips out you will have no power to the drive. The shaft of the drive where the spline engages the engine is the coupler. There will be allot of rubber pieces or aluminum shavings.
I have some very fine aluminum shavings in the engine compartment on the side of the starter. Could those filings be from the starter? If it is the coupling, how do you change it? Do I need to remove the entire stern drive, the engine, or is there an easier way to remove the coupling? Like could I leave the engine in, and remove just the stern drive? If I have to remove the stern drive I will replace the bellows, and Tilt/Trim senders at the same time. I was going to buy a hinge pin tool and a bellows expander tool. Are there other tools I need for this job?
Hi Frank, Aluminum is not from the starter as the starter drive is steel as is the flywheel. The engine coupler is aluminum and the drive and the engine have to be removed to replace the engine coupler. # XXXXX is the early model version of # XXXXX is the engine coupler which is bolted to the flywheel.
It seems like the coupler bolts on to the back of the engine. There is probably 6" between the engine and the transum. It might be tight, but couldnt I leave the engine in place and remove the coupling from the side?
No the engine and drive haver to be removed. The engine has to come so far forward that there usually isn't enough room. The coupler is at least 6" inches deep. That means the engine has to be moved forward at least 8" to get the coupler and flywheel housing off. If you have to move the engine that much forward it is just as easy to lift the engine out of the boat. To lift the engine out you don't have to go forward just up.
OK. I'll plan on removing both the engine and the stern drive. I also have a small water leak trough the transum. It appears that the water is coming in around the bottom bolt on the starbord side of the stern drive plate. Is there a gasket that is leaking? Any suggestions on fixing that leak?
When you get a leak around the transom seal it usually means there is a failure of the seal # XXXXX bolts leaking or the transom has gotten soft allowing water in. If the transom is soft this means there is some rot in the wood causing the would to shrink and move allowing water in. This will require removal of the complete transom assembly for inspection and repair of the leak. If you use sealer and don't remove the transom assembly the leak will continue. Sealer will only be temporary. Since you are going to have the engine and drive removed this would be the time to do the repair. I have seen many people just try the sealer route to no avail having to do it all over again removing everything. It is better to do it right the first time then do a band aid.
I have been working on the repairs that we talked about a while ago and have an issue I need help with. Not really sure on terms so bear with me. I want to replace the shift cable bellows. Therefore, that means that I need to take the shift cable out to get the new bellows in. The problem is that the nut that holds the shift cable inplace on the bell housing wont come out. I presume it is a regular thread. It it brass and I think I've stripped it. Any suggestions on how to get that brass nut out? Or is it reverse thread by chance? I bought a special ratchet with an open in the middle to be able to get to the nut.
Hi Frank, If the shoulders are stripped you will have to drill the brass fitting out. There is a tap 1/4-18(NPT) pipe tap once you get the fitting drilled out..
Can I pull the shift cable through the transum plate the other way?
The cable has to be pulled from the transom side out. Heres the instructions. http://www.mercstuff.com/shiftcable2.htm
1) I'm debating on changing the shift cable between the engine and the outdrive but dont really want to do it if it isnt necessary. What are some things I should look for in determining to replace it or not?
2) Also, since the engine is in parts, what is the best way to winterize it? I live in VT so it freezes.
The cable from the drive is your problem. As for winterizing just make sure there is no water in the engine remove the drain plugs on the side of the engine block and disconnect the hoses on the bottom going to the manifolds.
Cable from the drive? What do you mean?
You mean all this time I have been going back and forth with you, you don't know what the cable is that goes to the drive? The cable you ask about pulling from inside or through the transom? I guess you haven't been reading my posts? I even posted instructions on how to replace the cable. Here they are again. click here
Just wanted to make sure we were talking about the same thing. Oh, I've definetely been reading all your posts. I've even printed out that document and have read it thourougly. I'm new to this so the terms are a little new for me. But, I still dont know how you know the shift cable should be replaced. When I look at it the shift cable outer black tube it seems to be in OK shape and the inner metal linkage looks fine. And, I dont really want to drill out the nut on the bell housing if I dont have to. But, obviously, if I should do it, I should do it now while I have it all apart. looking for some advice?
The symptoms you have are a bad shift cable, stalling when going in or out of gear. You can't look at that cable and tell if it is good or bad. As you stated you are new to this. If you can tell by looking at that cable it is good or bad then you are better at this than I am.
OK. That's what I needed to know. I'll change that also.
Ok Frank keep me posted if you have any issues. Thanks Tan
I am installing new tilt/trim position and limit sensors. There is a small plate where the wires go through the boat. That small plate is held on with two 7/16" head (I think 1/4x20) bolts. I have removed the bottom bolt without much issue. The problem I have is that I cant get to the top bolt. I've bought numerous wrenches and ratches to try to get to that bolt but it is a very tight place. I also tried taking off the I guess it's the gimble ring (not sure that the right name) It has the cotter pin and bigger pin in the bottom and 2 bolts on the top. But, there must be somthing on the top holding it in because I cant get it out. My goal is just to remove the plate for the wires if you can tell me a trick I'd love to know how to remove that bolt to get the wires through.
The best tool to use is a long 1/4 in drive extension with a 7/16 swivel socket on the end of the extension. This is the most successful way to get to these bolts.