Engine diagnosis

[javelin]

We have a little 4.5 Avon rib with an old Johnson 30hp.

The engine number states that i was built in 1992 but it looks more like a late 80's engine.

Anyway the engine has been great and up till now bulletproof.
However recently we cant get a spark.
I tried a volt meter on the leads coming from the Gen to the Coils and then turning over the engine but I get no reading.
So my guess is the generator is faulty.

Are there any other tests I should try before dismantling the flywheel.

[m chappelow]

how about stop button has corrosion inside causing it to earth out.has it got points or is it electronic solid state

[big kev]

i found the lanyard switch corroded on mine i switched the motor off via the lanyard to check it then found it would not restart tried allsorts then took switch apart. it was v corroded inside cleaned the contacts inside fired up first time [dont drop the spring from inside the switch like i did it took ages to find]

[outboardtech]

Javelin mate , disconnect the MAIN ENGINE WIRING LOOM going from the control box to the engine . Ok once you hace disconnected this LOOM connect a battery directly too the starter and CRANK it over . Take the plugs out and put them into the HT Leads and GROUND them too the engine block . If you get spark you then have a problem @ the control box end ( key switch , stop circuit ) if STILL NO SPARK then you have a problem on the motor . try do that first before pulling the flywheel off . Any ? fire them too me . cheers baz

[javelin]

The engine is a pull start.
No battery and it seems no external ignition box outside the generator/flywheel.

The loom consists of two LT leads that go to the coils.
One black wire which earths on one of the coils mounting bolts.
The two other wires are yellow/black ish as the colours have faded a lot and seem to change in their length.
I guess these are the kill switch wires.
The kill switch was broken circuit when "ON" so disconnecting these from the switch ensures the engine is on.

Hope this helps.
I've added a few photo's and can add more with more detail if required.

Cheers

[javelin]

I wipped the flywheel off to have a look.

The cdi unit looks to have taken a knock.
I guess this is the root of my problem?

What do you think?

Any ideas where I can get another?

[m chappelow]

reason i asked has it points or cd unit ,as with points its not often both sparks will fail at the same time unless its to do with stop or kill switch at fault , ,how about worn metal particals or rust shorting out on the flywheel to the gap between the cd unit .though now looking at the latest pics looks like a new one would help. is there any wear or movement on the upper crankshaft bearing or excessive end float if there is even a new one might go the same way .

[javelin]

The shaft seems pretty tight, with no obvious slop.
There is wear showing on the flywheel and on some of the stator heads but nothing really significant.

I gather there is a replacement for this unit from the States via ebay and it's mounted outside the flywheel and comes with a new sensor but at $130 it's not cheap if this is not the problem.

Edit : Just had another look at the shaft play and there is some,
possibly .3mm, enough to feel but not enough really to see.
Does this indicate an engine rebuild is required?
If so I can see this engine going in the bin.

[javelin]

Tried to buy a replacement CD / powerpack on ebay but the seller is in the States and whilst they say they do overseas delivery they will not answer or respond to our questions or acknowledge our details.

Does anyone know where I can get a replacement CDI for the Johnson in the UK?

[David G]

Google brought these people up:

http://stores.shop.ebay.co.uk/Seacat...__W0QQ_armrsZ1

Not used and have no knowledge of them................

[Chris]

http://www.mareng.co.uk

These guys do aftermarket powerpacks for Johnson / Evinrudes.

I used them when I had my Johnson 90 and found them to be very helpful.

Chris