No spark plug spark... 170 MC , 1985 Sea Ray

[nola mike]

Wondering if something is intermittently shorting to ground the coil neg. Open the points and check for continuity to ground from the coil neg.

 

[Scott Danforth]

could be sloppy dizzy bushings

pull the cap, pull the rotor. grab the shaft and wiggle. if the shaft moves more than .007" radially or .020 vertically, pull the distributor and go to napa and spend $10 on two distributor bushings.

then put the thing back together, re-gap the points, verify the dwell and then set timing.

 

[Scott06]

But now he says he has no spark with or without the jumper cable. That jumper would bypass any problem from the R terminal, wouldn't it? I'm thinking he may have multiple issues. Unless possibly the jumper was not making good contact this time. Are we sure there is 12V on the coil terminal itself with the jumper in place, not just on one of the wire terminals.

Exactly if supplying 12 v direct from battery wouldn’t matter if there are upstream voltage issues

 

[Scott06]

Wondering if something is intermittently shorting to ground the coil neg. Open the points and check for continuity to ground from the coil neg.

Chaffing on wire from points to negative side of coil can do this

 

[glennj3]

Hey, the coil wire had slipped lose. It fired right up with the 12 volt jumper again.
My distributor wires slip off frequently causing skipping. I put nylon ties on them but it does not seem like I should need to do that. Wrong wires?
R terminal and coil sounds right but I can’t figure how to trace or fix it (just confusing) that wire goes from the negative coil? to the solenoid at the starter or the other solenoid. I don’t know which wire I’m looking at and I don’t think there are any relays between them?

 

[Scott Danforth]

the wire on the coil negative goes to the points. the other two terminals there are the shift interrupt and the tach. we covered this before.

 

[Scott06]

Hey, the coil wire had slipped lose. It fired right up with the 12 volt jumper again.
My distributor wires slip off frequently causing skipping. I put nylon ties on them but it does not seem like I should need to do that. Wrong wires?
R terminal and coil sounds right but I can’t figure how to trace or fix it (just confusing) that wire goes from the negative coil? to the solenoid at the starter or the other solenoid. I don’t know which wire I’m looking at and I don’t think there are any relays between them?

Yes start with correct wires...I bet you can take needle nose pliers and stretch the connections so they firmly fit. Didn’t u just replace all this? Start by zeroing the mileage with wear otherwise you are chasing garbage

 

[glennj3]

Yes start with correct wires...I bet you can take needle nose pliers and stretch the connections so they firmly fit. Didn’t u just replace all this? Start by zeroing the mileage with wear otherwise you are chasing garbage

The wires and full tune up was done almost a year ago by my mechanic. The distributor cap plug wires started slipping off very soon. I used the nylon ties and that seemed to help but the tie came off of the coil wire, it unplugged itself that fast!
I just don’t know how to fix that R wire deal! No relays in that harness I’m pretty sure.

 

[Scott06]

The wires and full tune up was done almost a year ago by my mechanic. The distributor cap plug wires started slipping off very soon. I used the nylon ties and that seemed to help but the tie came off of the coil wire, it unplugged itself that fast!
I just don’t know how to fix that R wire deal! No relays in that harness I’m pretty sure.

there are no relays In The harness. Start with first things first. If the plug wires fall off fix that first. I would suspect this is part of your intermittent spark issue . Rule this out.
Check if there is 12 when cranking On the r terminal. If there is it replace the starter, if there is 12 v run a separate wire from starter up to coil. It’s the only way to narrow down the possible issues

 

[nola mike]

The distributor cap plug wires started slipping off very soon. I used the nylon ties and that seemed to help but the tie came off of the coil wire, it unplugged itself that fast!

Did this not seem like relevant information before now?

 

[isaacs]

Multiple issues! Can you find the "R" terminal on your starter--I think it will be marked as such right on the plastic on the starter. If so, just run a jumper from the "R" terminal to the plus terminal of the coil and see what happens. (Without the previous jumper from the battery.)

 

[glennj3]

Did this not seem like relevant information before now?

Correct, was an easy fix!

 

[glennj3]

Multiple issues! Can you find the "R" terminal on your starter--I think it will be marked as such right on the plastic on the starter. If so, just run a jumper from the "R" terminal to the plus terminal of the coil and see what happens. (Without the previous jumper from the battery.)

I’m thinking the R terminal is the major red wire on the starter but I’ll look fir the R on it.
Thanks!

 

[Scott Danforth]

I’m thinking the R terminal is the major red wire on the starter but I’ll look fir the R on it.
Thanks!

No

that is the B terminal

the s terminal is the one that the comes from the starter pilot relay

the R teminal is opposite side of the s terminal

 

[isaacs]

No

that is the B terminal

the s terminal is the one that the comes from the starter pilot relay

the R teminal is opposite side of the s terminal

It's hard to say for sure, but if we compare this picture with Glenn's, it appears that his "R" terminal is empty. I don't even see a hex nut on there that would have held a ring terminal.

 

[Scott Danforth]

It's hard to say for sure, but if we compare this picture with Glenn's, it appears that his "R" terminal is empty. I don't even see a hex nut on there that would have held a ring terminal.

agreed, looks like there is no wire coming off the R terminal

 

[nola mike]

no, the boat uses a 1.5 ohm coil requiring a balast resistor for running and gets full 12 volts when cranking via the I/R terminal on the starter. that is the way the boat is wired.

Whoops. Everyone forgot that this is a 170. The 12v coil voltage is supplied by the slave solenoid, not directly by the starter.

 

[isaacs]

Whoops. Everyone forgot that this is a 170. The 12v coil voltage is supplied by the slave solenoid, not directly by the starter.

Now the colors make sense! If the Pur/Yel wire looks good between the coil positive and the slave solenoid, then run a jumper between those two points just to make sure there's not a bad spot somewhere you can't see. If the engine still won't start there must be something wrong with the solenoid, right?

 

[glennj3]

I’m more clear on where to look now. I just couldn’t locate the wires being discribed, causing me more confusion. It’s also somewhat difficult to lay across the engine and visualize where the wires from the slave solenoid to the starter solenoid go exactly.
Believe me, I have been into it all myself having replaced the starter, slave solenoid as well as the heat exchanger. Tough work!
Another note of interest is that I don’t use any of the old stator charging system. Several years ago I put a standard alternator made for boats in it. So those wires from the regulator are cut off.
I’ll go out and look at it again today, I have to winterize her due to temps going to drop this week.
I certainly do appreciate all of your help!

 

[glennj3]

I checked the + terminal on the coil with key on. Read 12.5 volts. I was checking the slave solenoid & I noticed the kill switch that I removed a yellow & green wire from earlier this week, I neglected to connect both ends. So I re connected as in the picture.
Before doing anything else I turned the engine over with the key. I thought I saw the spark plug tester spark, it may have been a weak one.
I connected a jumper from the coil to the slave solenoid purple & yellow wire. Turned the engine over & it cranked up, the key would not turn it off so I quickly removed the wire. Actuality the 1 st time I connected the wire the engine turned over with just the wire connected!
Anyway, now it fires up like it should do normally.
Don’t know what I did.