Reply With Quotepity the poor cabbie....Originally Posted by bluefin59
Sound like a fuel pump diaphragm on the motor is on the way out as it’s struggling under throttle, I used to change mine bi yearly at service . Has yours been changed if so it’s probably a cabbie pull down job usually done by professionals with an electronic cleaning bath and reassembled and adjusted . Matt
A bad days fishing has got to be better than any day at work......
pity the poor cabbie....
"I have been using the boat every weekend but last month it sat for 4 weekends in a row."
"the old filter was full sand"
Yep, with what you've described and the work you've done so far signs point to a gummed up or blocked carb.
If it was a fuel supply issue the whole motor would begin to bog down, not just one cylinder (one bowl would run dry slightly before the others, but they will all begin to starve of fuel in short order).
Running fuel straight from a funnel and piece of hose to the carbs will eliminate any fuel pump or fuel supply faults. Or you can quickly pull the fuel line to the affected carb off while it's running and see if there's fuel coming out. There will be enough fuel in the bowl to keep it running for a short while.
The carby clean will help dissolve any varnish or fuel/oil residue,but to clean the jets and internal passages of any blockages properly you will need to hit them with an air gun. Once they're back on and the engine is running properly make sure to re balance the throttle linkages as chances are they will now be out of adjustment.
Bloody spellcheck, Carbie
A bad days fishing has got to be better than any day at work......
So ... From what I have read so far with the thread post, I will:
- Rebuild the pump
- Rebuild the Carbie
- Bought a spark tester
- Bought brand new tank and pimer bulb fuel line kit.
And see how I go.
yes my fear is WW3 will start because of spellcheck!!!
I rebuilt the carby today and it looked spotless before even starting cleaning.. So I had doubt and wanted to check the spark again because of how the 3rd cylinder sound and behaves.
Well..... That's the lower coil.. The ceramic is in pieces...
Attachment 119020
Lets hope it is the issue - But definitely looks like it!
Well done mate, I can't see the photo but it sounds like you might've found the problem.
F*** Sake! It does my head in ...
2 new coils as the middle one was also broken.
I removed the tan wire from the CDI to isolate the issue and after cutting off the tan wire, I have no sparks at all on the 3rd cylinder ...
So now my money is either CDI, regulator or Stator.
CDI stands for Capacitor Discharge ignition so it stands to reason you wont get spark without the CDI unit attached.
Did you check the spark TIMING of the bad cylinder on the running motor or just for a static spark? This will narrow it down greatly.
Put all of your original ignition components back on and get it running again, then swap the plugs and both ends of all the ignition leads to new cylinders.
Check to see if the problem moves as well. If not then you can rule out plugs and leads and move on to the next component in line.
Continue moving upstream until you can isolate the troublesome component and work from there, move each part to a new cylinder and see if the problem moves, if it doesn't then it's something else causing the problem.
Keep at it and you will find the problem as long as you are methodical and start testing components as you go. don't buy any more parts until you can isolate what the faulty component is.
Switch box CDI's were certainly a weakness on Mercs. If and that is a if it is a switch box issue don't even bother pricing one locally just grab a genuine Merc from the states for a fraction of the price and grab yourself a few other bits impeller etc to make it worthwhile.
DoNotFeedTheTrollsAandBelligerent
I just checked for a static spark - To put in context, I have been advised to disconnect the tan wire from the cdi and run the engine in order to isolate the issue.
When the tan wire is connected, I get a spark at idle but the when I start revving, spark fades out, then at higher RPM I get no sparks.
When the tan wire is disconnected, I dont get any spark on the 3rd cylinder.
I'll troubleshoot again from what you've said.
Thanks for your help!
When u remove the spark plug from the engine block your eliminating the problem so the spark plug will fire normally and look ok to you its when u place the spark plug back in the engine block the electrode is earthing on the engine block instead of sparking
i have had brand new NGK spark plugs break down because they were faulty, its your spark plug 100 percent but dont replace it without testing it
its a very simple easy test
Hi Gazza,
I tested the plugs and Leads and the readings are to specification. Unfortunately, I can't go any further as I don't have a DVA ..
I am lost (haha) - It's easter weekend soon and and Anzac day and no boat
Time for a new one then 😂
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