Second Opinion needed.

[Bradster941]

Second Opinion needed. <br /><br />Same old story, different day here in South West Florida.<br /><br />Old man on a fixed income has a Dock Side Marine Mechanic fix his engine that is dropping cylinders intermittently. Charges him $385.oo to replace a ignition coil and Stator with used parts. Surprise, it still doesn’t work and he wants to charge more money to replace the timer base to see if that fixes it. ( A regular Parts Changer ).<br /><br />Anyways, I took a look at it today, (a 1982 90hp Johnson), and found #1 and #3 intermittently dropping spark but not at the same time. Also, #4 dropped out for a few minutes and then came back strong and hasn’t dropped out since. <br /><br />Did a Ohm test on both power packs and the timer base.<br /><br />Timer base ohmed out ok<br />Port Power Pac ohmed ok.<br />Starboard Power Pac, (A to D ohm test in both direction) wasn’t infinite in 1 direction on the isolation Diode though high resistance.<br /><br />I’m ready to condemn the starboard power pac as 1 & 3 will drop, never at the same time, in and out, then run fine for a while, and did read that a bad isolation diode can effect the other power pac, (thus #4 dropping out).<br /><br />Just wanted a second opinion before I ordered a new power pac. as this is gratis to help this old man out and if I’m wrong, I’ll probably pay for the part myself and still have a problem on my hands.<br /><br />What do you think? <br /><br />Ps. Good compression all the way around.

 

[mikeyzx2]

Re: Second Opinion needed.

Welcome to iboats, you definitely picked the right place!<br /><br />Well I think that mech should be hung.....it's likely there's nothing wrong with the "bad" parts unless there was obvious physical damage to them, like cracked insulation and leaking potting compound. He shoulda did some troubleshooting before throwing parts at it. It's possible the power packs are failing, but make sure you double check everything else, like grounds, wiring, and get the OEM manual specific to that motor, it's the best fifty bucks you'll ever spend. There's a slew of guys on here that know alot about these motors.

 

[DJ]

Re: Second Opinion needed.

Salt Water Engine? Look at every ground you can find. Pay special attention to the negative battery cable engine block ground. <br /><br />Remove it and clean it.

 

[Walker]

Re: Second Opinion needed.

Originally posted by DJ:<br /> Salt Water Engine? Look at every ground you can find. Pay special attention to the negative battery cable engine block ground. <br /><br />Remove it and clean it.

Do the coil grounds too.

 

[Dhadley]

Re: Second Opinion needed.

Disconnect the kill wire between the 2 packs and test spark again. If the isolation diode is bad in the port pack, it'll kill the starboard pack.

 

[rabidfish]

Re: Second Opinion needed.

Then go back and check the grounds again...<br /><br />You know... the only proper way to check ground is to disassemble it, clean it, and remake it. To proof your work, check with ohm meter.<br /><br />Remake the battery cable ground connection at the stud, and at the battery terminal also.<br /><br />(I know a guy who has a friend that worked for a couple who's gardener tried for 3 days to fix a problem like this only to get burned by the battery cable connection on the block stud) Man am I ever that that never happened to me!

 

[Bradster941]

Re: Second Opinion needed.

Thanks DJ, Walker and Rabidfish.<br /><br />I cleaned all grounds;<br />Battery terminals<br />Block ground<br />Power pack grounds<br />Ignition coil grounds <br /><br /> Thanks Dale, <br /><br />I cut the kill wire, (black, / yellow tracer) to the starboard pack.<br />Ran for a few minutes, then it dropped the port cylinders (2 &4)<br />Reconnected kill wire, and am back to original problem.<br /><br />Lets recap.<br /><br />Tested with engine running at idle, out of water, 1,700 rpms<br />Starboard side, ( 1 & 3 ) will intermittently drop either #1 or #3, never at the same time.<br />If #1 has no spark, pulling #3 plug wire will cause #1 to fire and replacing #3 wire results in both #1 and #3 firing correctly for a while, (1 to 7 minutes). <br />Then either #1 or #3 will drop out again. <br />If #3, removing #1 plug wire will get #3 to fire again, like above, only in reverse.<br />Sometimes she will fire on all 4 just fine for 10 minutes, then suddenly drop a cylinder.<br /><br />According to the manual, on the power pack four wire connecter, ohming in both directions between “A” and “D” should result in infinite resistance in one direction, low resistance in the other direction. <br />Intermittently, I have found high resistance in one direction, 28.3 M ohms, and low resistance, 1.8 to 2.3 ohms, in the other direction. Then, a few minutes later, infinite resistance in 1 direction, low resistance in the other on the starboard Power pack.<br /><br />Question, <br />This is a 1982, 90hp, and I have a 115 Sea Drive. Would my 115 power pack on the 90 be compatible for testing?<br /><br />Anything else I should check?<br /><br /><br />Thanks guys,<br /><br />Bradster. <br />

 

[Bradster941]

Re: Second Opinion needed.

 

[clanton]

Re: Second Opinion needed.

Switch the packs, if the problems move, then the pack is bad.

 

[Bradster941]

Re: Second Opinion needed.

Good idea Clanton,<br /><br />Unfortunately, I would have to cut and splice wires to the starboard ignition coils as the for mentioned mechanic cut the duplex connector off when he changed that power pack out a few years ago.<br /><br />That power pack looks like an aftermarket and the only marking on it is a <br />Serial number of 404899<br /><br />On my boat the power pack is <br />OMC<br />CD4<br />583110 21 LX OA<br /><br />Can anyone tell me if the later would be safe to install for testing?<br /><br />Thanks,<br />Bradster.

 

[OBJ]

Re: Second Opinion needed.

Bradster....the correct PN for the PP on your engine is 582125 with no superceding numbers. (Just did a little looking)<br /><br />The existing PP may have been spliced in cause the leads were to short.....? Don't know....

 

[Bradster941]

Re: Second Opinion needed.

Thanks OBJ<br /><br />Would you not recommend I put 583110 on for testing?<br /><br />Also, what would be the cross ref# for the Sierra. Couldn't find 582125 here on the iboats search function?

 

[Bradster941]

Re: Second Opinion needed.

Hold the phone.<br /><br />Went back and re tested the timer base on the starboard side and now it reads open between “A” & “C” .. Aaaarrrrrrrrgggggg. <br /><br />Lesson learned to check and recheck.<br /><br />Anyone have a part # for this timer base and does iboats carry it ? <br /><br />Much thanks to all who have responded. <br /><br />Bradster

 

[MCM]

Re: Second Opinion needed.

The p/n for your timer base is 582041 superceded to 583376, I don't see it listed at iboats, no aftermarket p/n's found either.

 

[Walker]

Re: Second Opinion needed.

Unfortunately, I would have to cut and splice wires to the starboard ignition coils as the for mentioned mechanic cut the duplex connector off when he changed that power pack out a few years ago.<br />

Then switch the pack and coils as a unit. That will isolate the unit. If the problem switches side then you either have a bad pack or bad coils. If the problem stays on the same side then you problem is up stream of the pak

 

[Bradster941]

Re: Second Opinion needed.

Thanks MCM <br /><br />583376 is what I figured but was only able to go back to 84.<br />I'll keep the 582041 in the back of my head incase I find one at the bone yard.<br /><br />Thanks again everyone for your help....