no spark 70 hp late 80s

[bob johnson]

I picked up an 89 Johnson 70 hp...it had been rebuilt or refurbished(?) 10 years ago when it was installed on the sellers boat....before he could take it out on the river a tree fell on the boat....he dragged it back of the barn and left it. I just boat the motor.,,,,has great comp, cranks over strong...fuel pump has a VRO2 tag on it so that seems newer than 89.... so I believe the work was done... I sprayed mixed fuel into the carb openings and into the cylinders..it wouldn't fire...so I pulled the plugs and grouded and they are not sparking...( I cant find my spark tester!!)...but the grounded plug should spark!....what are the steps to checking for spark? the safety switch in engaged on the control .... the key cranks......electrical ...not my suit!

 

[boobie]

Go to cdielectronics.com for ignition trouble shooting.

 

[bob johnson]

nice site. So I looked the motor over pretty good, and I don't remember seeing any wires that you can UNDO.....ie that have bellet connectors that are made for pulling apart. The CDI site says to "disconnect" the black/yellow wire at the power pack to check the stop circuit . but I didn't see a place to do that...if I pull the power pack off the motor will I be able to disconnect that black/yellow wire?

I really suspect the stop circuit, because I put this control on the 40 HP I am selling to try and fire that thing over and I get the same exact results as I get when I put the controls on the 70 I am putting on my sons starcraft..... now they both have not run in a long time......but the controls are definitely a common denominator!!!!!!


bob

 

[jakedaawg]

There is an amphenol connector coming from the power pack. Disconnect it. Jump all wires that are not blk/yel. If you have spark then ohm the key/kill switches and look for a short to ground on the blk/yel wire

Congrats on the new "rank" rear admiral

 

[bob johnson]

I pulled the power pack to find the wires under it, they weren't that long before they went into the rubber connector.....I had to cut the black sheathing off that protected the wires, and I found the black/yellow and I cut it.....motor fired right over when I went to start it.... only took me about 4 tries to crank her over and she ran and stayed running nicely......not bad for motor that was sitting for 10 years.... all the cylinders are firing and giving power... I pulled the plugs one by one and I could hear the motor drop rpm....

sooo I am guessing that the control has a bad stop circuit wire in there somewhere.. if I start her again...is there an easy safe way to shut the motor down quickly????

 

[jakedaawg]

flood it. You do not need to start it agaain though. Sticky at top has diagram for key switch tests. Also disconnect blk yel at key sw and power pack. Check for continuity to ground but not through the power pack.

 

[bob johnson]

how do you flood a motor that already running?..... I pulled two plugs....but I think I tore the boots in the process.....and I had one coil sparking to itself!.....

bob

 

[jakedaawg]

Flood it by holding the key in till it dies. But you already diagnosed. You should not need to run it again til you have preformed the above mentioned tests and reported findings.

 

[bob johnson]

thanks, I used the control from my 1987 Johnson 48 special and its works fine... I have a ton of projects, ( redoing a 1/4 acres of grass) plus I still have a a lot of work to do on the 18 ft starcraft, so I am setting the defective control aside for now....... hopefully when I do get back to the control.. the problem is NOT in the long cable...in the box should be easy to trouble shoot, now that I know to look there.

bob