Need help testing solenoid on 70's merc 1150 - just replaced internal harness

[WA-Newb]

First off I have no idea if this motor was actually a great runner as stated by the PO...so far I have seen some pretty incredibly sad wiring so who knows what he did in the past etc. He said it would 'fire right up"...lol

Well after replacing the internal wire harness, cleaning all connections and installing a brand new battery all I get when I turn the key is clickkkkkkkkkkkk...and not a single click but a rapid repeating noise. The noise sounds like a car with a bad battery connection or semi dead battery.

I "think" I have installed all the wires correctly based on the diagram (plus they are color coded) but I could have messed something up somewhere.

Can someone please tell me how to proceed in testing OR bypassing the solenoid...and tell me if the small two wires on the solenoid (yellow and black) matter which post they are hooked too. I did try both ways and got the same result.

When putting a volt meter on the two large solenoid posts without the key turned on I get about 12 volts.
And...if I bypass the solenoid and go directly from battery to starter the starters spins fine....just not by using the key.

Thank you.

 

[Bosunsmate]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Doesnt normally matter which put way they are put on But who knows if its got the original solenoid on it.
Put jumper cables from the battery with one from batt + to solenoid large positive and negative from battery to a real good ground on motor. Try again
If that dosent work run another wire from the little solenoid neg to the ground jumper attached to the battery and engine. Try again, if that works clean all grounds.
If not run a wire from the large solenoid +ve which has a jumper already attached and touch it to the little solenoid postive (Do this with the grounds all still attached).
Also try +ve jumper from +ve output of solenoid to check wiring from starter to solenoid

Sometimes you can get 12Volts but itl drop right off when the currents drawn

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

I woke up..saw your reply and ran out there before evening making coffee...lol

Your first suggestion worked...it turned over just fine.

Doesnt normally matter which put way they are put on But who knows if its got the original solenoid on it.
Put jumper cables from the battery with one from batt + to solenoid large positive and negative from battery to a real good ground on motor. Try again

So does this mean it's a bad connection? If that's the case then I have no idea where the connection would be. I have taken apart every connection, even took out the battery selector switch all together and cleaned all connections very good.
I do see some peeling / cracking on the main positive lines insulation...way under the splash well of course.
Does bad insulation / bare wire cause loss of voltage?

Thank you very much...now I am going to make coffee and hopefully see if this thing has spark.

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Ok..so may need to start a new thread but in case someone knows what I can try next to get this thing to fire...or what to test to see why it won't fire please let me know.

There is blue spark from all plugs..I sprayed just a bit of mixed gas into the cylinders..turned it over with plugs out (have already been soaking cylinders)...sprayed a mist of mix into the carbs and put plugs back in, primed the line and tried to start.

It didn't seem to even try to fire up. It turned over but never gave me hope of run.
Ideas?

Thank you.

 

[Bosunsmate]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

So starters now working ok?
Must be either a bad ground /wire connection or bad positive cable. Sounds like the positive cable is suspect from your description of it. Just replace which one it is by removing either jumper cable and retesting
Have you checked engine compression?
If you can make a spark tester see if it will jump about 7/16 gap?

Also spray premix into cylinders reinstall sparks and see if it fires momentarily

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

I started to check compression and then broke my gauge (the hose) when trying to make the bend to the bottom cylinder.
The ones I did test were all at 125psi and I got four of them tested.

I will see about making the spark jump the 7/16...all I have for a tester right now is the type that shows it light up or not and all of them do light up...plus when I had the plugs out I bungee'ed them all so they were grounded to the bottom cowl and saw blue spark from each line...just not sure how far it will jump.

I did also try the premix spray and got nothing.

And I am pretty sure it's the positive cable that's bad too...just figures it's the one that will be hard to work on due to location and routing...err...lol

Thanks.

 

[Bosunsmate]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Do you have a timing light?
If so see where timing is at.
Clean spark plugs. dry them and then put them back in. Ground all the coil ht wires, dont connect them to the spark plugs. Turn the key to have the starter do about 2 seconds, do that twice then remove plugs and see if they are all wet with fuel

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

I will dry the plugs as you said but also just got home from buying an adjustable spark tester so I can see how far it jumps.
Will I need to check each plug to see if its jumping the 7/16 of an inch?
And do I leave the plugs in while doing this and just put the gap tester between the boot and plug checking one at a time?
Thanks....out to the rain I go...lol

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Just dried all plugs..put them back in, primed fuel bulb and turned it over for maybe ten revs...no wetness on plugs...sigh.

Also got the compression on the next cylinder and it is just over 100 (first four again were 125)...still not sure how to get to the bottom cylinder.

I will go check spark jump now...and will check to see if anyone updated my thread about if there are jets or whatnot that can be cleaned on these carbs while they are still attached. I am trying to determine if this motor will be worth doing carb rebuilds etc. before spending that money and time since I may just end up parting it out. If it looks like a good runner then I won't mind spending the money on the carbs (can't speak for my wife though...lol)

Just want to make sure there isn't some 2 million dollar part that is toast on it first...can't afford to throw good money after bad..or whatever that saying is...lol

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Just tested spark jump / gap on each cylinder...it jumps the gap at 1/2 inch on each cylinder (I was off a bit when measuring at first).
Should that be sufficient or should I reset the gap and test again? Without remote starter am needing to have someone else turn the key or would have already done it.

 

[Bosunsmate]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Try undoing the drain plug in the carbs to check that fuel is getting through to them all (no sticking floats etc).
you should spray some more premix into the cylinders since they are getting dry and then get someone to crank the starter while you hold a banknote in front of the carbs. Check the note is sucked in towards the engine (hold on to it tight)

You can also try that wetness test again with the choke on.

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

I just updated my other thread and now for this one...

So I finally got it running but only after removing the bottom jets and the idle jets...cleaning them out with carb cleaner and air best I could, reassembled and sprayed pre-mix (with a hint of starting fluid) into the cylinders...it fired right up and sounded good.

It will however not start unless I do this spray into cylinder method and that's what I am working on troubleshooting now.

I am not sure if I should start a new thread or continue on this one but here it goes...NEWEST PROBLEMs.

Problem 1. Starter dragging
So far I know I have a bad positive cable going to the starter solenoid since I need to have a jumper between the battery and the solenoid to get it to turn over. That being said...wehn the plugs are out it turns over very fast with this method but when I put the plugs back in and try to turn it over it really drags...almost feels like it's restricted somewhere. Now if I spray some mix into the cylinders it does start right up. If I don't spray the mix it just cranks slower and slower....brand new charged battery / keeping it charged and testing voltage often.

Problem 2. Engine will die if I unplug the positive jumper on solenoid while running
When the motor is idling and I unplug the jumper that I am using from battery to positive post on solenoid the engine dies.
Thought about ignition wire somewhere but doesn;t make sense that it would be constant hot to solenoid to me? Ideas where to look?

Problem 3. Choke switch does nothing
I can manually use the choke by pulling on the lever but would liek to know how to test the choke solenoid to see if it's bad or if yet another wire is shorted somewhere. Do I just add 12v to the connector on the choke solenoid and it should do it's thing? Or is there a different way of testing this?

Bonus Problem - Having to spray fuel mix into cylinders to start
I would still like to figure out why I have to spray the cylinders to start it...I am hoping it will get better after its ran a bit but now I have ran it four times and still nothing...BUT that could be from the dragging starter as well. I can rev the motor just fine when its running and if I prime the bulb as hard as possible fuel does come out the carbs so am not sure it is still a carb issue.

Bosunsmate...
Should I still try the note method you mentioned? Just don't have another set of hands here yet today.

Thank you very much for the help thus far

 

[Bosunsmate]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Sounds like you need to replace the battery cables and clean all the grounds both positive and negative
Yes connect 12v to the choke and it should operate it
Then see if that fixes it at start up and you dont need to spray it anymore
Yes do that test as you want to make sure no cylinders are running dry

 

[bbennet2]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

I just updated my other thread and now for this one...

So I finally got it running but only after removing the bottom jets and the idle jets...cleaning them out with carb cleaner and air best I could, reassembled and sprayed pre-mix (with a hint of starting fluid) into the cylinders...it fired right up and sounded good.

It will however not start unless I do this spray into cylinder method and that's what I am working on troubleshooting now.

I am not sure if I should start a new thread or continue on this one but here it goes...NEWEST PROBLEMs.

Problem 1. Starter dragging
So far I know I have a bad positive cable going to the starter solenoid since I need to have a jumper between the battery and the solenoid to get it to turn over. That being said...wehn the plugs are out it turns over very fast with this method but when I put the plugs back in and try to turn it over it really drags...almost feels like it's restricted somewhere. Now if I spray some mix into the cylinders it does start right up. If I don't spray the mix it just cranks slower and slower....brand new charged battery / keeping it charged and testing voltage often.

Problem 2. Engine will die if I unplug the positive jumper on solenoid while running
When the motor is idling and I unplug the jumper that I am using from battery to positive post on solenoid the engine dies.
Thought about ignition wire somewhere but doesn;t make sense that it would be constant hot to solenoid to me? Ideas where to look?

Problem 3. Choke switch does nothing
I can manually use the choke by pulling on the lever but would liek to know how to test the choke solenoid to see if it's bad or if yet another wire is shorted somewhere. Do I just add 12v to the connector on the choke solenoid and it should do it's thing? Or is there a different way of testing this?

Bonus Problem - Having to spray fuel mix into cylinders to start
I would still like to figure out why I have to spray the cylinders to start it...I am hoping it will get better after its ran a bit but now I have ran it four times and still nothing...BUT that could be from the dragging starter as well. I can rev the motor just fine when its running and if I prime the bulb as hard as possible fuel does come out the carbs so am not sure it is still a carb issue.

Bosunsmate...
Should I still try the note method you mentioned? Just don't have another set of hands here yet today.

Thank you very much for the help thus far

I have a 73 merc 1500 and when I turn it over it really lags as well with plugs in with them out they spin fine. You said you sprayed premix and it turned over fine?

 

[bbennet2]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Also what is your premix ratio along with starter fluid

 

[WA-Newb]

Re: Need help testing solenoid on 70's merc 1150 - just replaced internal harness

Bosunsmate...thanks, I am on it today hopefully.

Also what is your premix ratio along with starter fluid

I do not know if I am doing this right so you may not want to follow it...lol

I dumped some fresh pre-mixed gas from my tank into a spray bottle...I spray that once into each cylinder (mostly for extra lube) and then spray a quick light spray of starting fluid into the cylinder...put the plug back in quick as I can. Oh and I take all the plugs out first so it's quicker for me to get to the ignition and hose after I spray the cylinders (scared it will dry out or empty before I get done each time).

Each time I have done this the thing fires right up...but without it it just has that sluggish spin and won't fire.

I will let you know if I get anything figured out...I posted in your thread as well.