135 merc starting issue (won't start, help needed)

[flaviobonzer]

Hi,

I have mounted a merc 135 black max 1990 on a boat few months ago, Fired it up all good started no trouble.
Haven't started it again until a few days ago and to my surprise won't start at all. HAs just been sitting on back of boat not doing anything since I last started it.

Cranks over no worries but doesn't even look like it wants to fire on any cylinder.

Pulled plugs out and seems to be quite a weak spark.

outboard serial oc 267170 40 amp stator etc

I have been reading up on electrical issues on iboats and have tested the stator ohms

I have:

blue wire- 2420 ohms

red wire - 70.6 ohms

blue/wht wire - 3930 ohms

red/wht wire - 71.2 ohms

cdi manual says blue should be 3200 - 4200 ohms, red 90-140 ohms

with my readings would you say the stator is failed? Or do I need to measure dva as well, some members have stated ohms readings not that reliable.

bias circuit reads 14250 on outside switch box and 14210 inside switch box

trigger wires read around 1230-1245 ohms so looks good as per manual.

Any help greatly appreciated.

cheers

 

[Chris1956]

Re: 135 merc starting issue (won't start, help needed)

Did you disconnect the switchbox killer wires (black/yellow) on each switchbox? That is usually first test. The CDIElectronics web site should have the stator and coil resistance values.

 

[Mfulfer]

Re: 135 merc starting issue (won't start, help needed)

Well on the stator test i have two questions ...... how cold is it where your testing...that will play a big part in your test. also why jump strait to stator. Did you spray a little carb cleaner in the carbs. that will give the engine something to run on. I am saying do this to see if you have a fuel problem. don't do this alot (has no lube value but if your looking for a test to eliminate fuel you will see something.

 

[flaviobonzer]

Re: 135 merc starting issue (won't start, help needed)

Cheers for reply.

Got it sorted today.
Yesterday made a dva adapter to measure the voltage from the stator. Got info from other threads on this forum. was very helpful.
Found the stator to be out of spec and giving a weak spark. initially thought it might be the stator as it was all 6 cylinders it wouldn't fire on not just one or one bank. checked spark at the plugs and didn't seem very strong.
Had pulled the stop wires off the switchboxes already to eliminate that side of things.

Got a new stator and installed . checked plugs and had good bright spark. Still wouldn't start... Pulled apart the carbs and cleaned them all up. BAck together and fired up nicely so must have been a fuel blockage also.

Did spray a bit of ether into carbs before to try to start it but still didn't fire so thought that it was completely an electrical issue. Didn't spray much as know it is not good for 2 strokes.

So we are up and running again thanks to this forum, Lots of great info to go through and learnt lots.

cheers

 

[flaviobonzer]

Re: 135 merc starting issue (won't start, help needed)

Also when engine fired up initially, wasn't quite prepared and had no hose attached so switched off the key and low and behold wouldn't turn off. Had to run and turn the tap on to supply water then was wondering how to get the engine to stop haha. ended up giving it a hug and blocking the the intakes.
So you can't turn off the engine if the stop circuits have been disconnected.

One thing I am wondering about. previous owner disconnected the oil injection. looks like he just unplugged the lines and plugged the loose ends. there is still oil in the top reservoir which gets pumped into the carbs when accelerating and I think some feeds into the fuel line also.
If I am using premix do I need to disconnect the oil injection form the fuel line and carbs or can I just leave it as is?
Smokes a lot on start up them mellows out.

cheers