1982 v4 140 loss of power

[Bigal77fishing]

Hi my name is alex from down under Australia, Iam currently having some issues with my outboard it seems to have lost a fair bit of H.P. I have recently had my 82 v4 140 ERUDE serviced for the first time ever as the boat has currently 70 hours use, (boat stored 17 yrs no use ) I put 50 hours of use in the last ten years and in that time it has worked as you would expect of a 82 2 stroke, plenty of smoke, heaps of power, and the odd time when it wouldnt start cold for anything and five minutes later it would go first tickle of the key. Anyway getting to my issue, pre and post service the motor would run on when the key was switched off, this fault was intermittent and was the main reason i got it serviced. I then phoned the mechanic and he instanty diagnosed this as a power pack issue over the phone whilst i was actually using the boat, the engine still had heaps of power at that stage, five minutes later on the water i lost a fair amount of low end grunt and holeshot was severely decreased, another call to mech and he suggested stop using the boat and replace power pack asap. Replaced power pack and the stopping issue was fixed but still down on H.P The mech then replaced fuel pump diaphragm and supposedly found junk in carbys he then test ran it and said it is good to go, i took the boat for a spin, still down on power. Iam starting to think another ignition component is faulty. Any ideas or tests that i can conduct without having to buy components would be very helpful. Cheers Alex.Also i might add the compression was checked and it was spot on, heads came of at service as inspection found thermostats coroded and not opening proper all new bits and pieces and aparently everything was ok

 

[ezeke]

Re: 1982 v4 140 loss of power

Be aware that any voltage riding the black and yellow kill wires to the powerpacks can permanently damage the powerpack; this often occurs due to a failed or failing ignition switch.

It's time to do a spark test and let us know the results.

Take the air silencer cover off the carburetors and place two fingers over each carburetor throat one at a time with the engine idling. Each hole should respond the same and if one does not, re-service that carburetor.

This link will help with electronic/ignition problems: http://cdielectronics.com/downloads...1978-1998 65-140 HP (Without Quick-Start).pdf

 

[emdsapmgr]

Re: 1982 v4 140 loss of power

When you check for spark, take a friend and an inductivie timing light out with you next time you are boating. Put the timing light probe on each of the 4 wires and check for solid, rhytmic spark flashes when you are on plane. The light will show misfires and nofires on a bad wire. Make sure the bottom plug wires are not grounding out on the rear cowling latches. If the spark looks ok and the compression is fine, then I'd be looking at a fuel/carburetion issue.

 

[SparkieBoat]

Re: 1982 v4 140 loss of power

Check all fuel lines first, make sure you got no cracks and are not sucking air. Change filters, check for a clog in the fuel tank pick-up, also make sure you have fresh/water free gas..also do the carb test already mentioned....
then do a spark test with a spark gap tester, less than $10 at auto parts store. each wire should create a blue- bluish/yellow spark at 7/16 gap, this will diagnose a weak coil, remove all spark plugs while testing...also check coil grounds and make sure they are clean...
Next do a compression check. Next will require a DVA adapter about $35 available online, you will also need a multi meter if you do not have one. the steps to test the rectifier, stator, and Power pack/s can be found at the CDI link already posted above.
O yea if you did not do it when the engine was service, change spark plugs (make sure you get/got the correct plugs)..also the water pump impeller needs changing, and the gearcase oil. Most outboard issues seem to be fuel related, so check all fuel stuff first....
that is a great motor that you have and well worth fixing and regular maintenance, even if you do not put many hours on it. make sure you use a fuel additive like Sea Foam to prevent carb clogs.

 

[SparkieBoat]

Re: 1982 v4 140 loss of power

o yea...you can also try pumping your bubble while having power loss to test for a bad fuel pump. I know you mentioned it had a new diaphragm..but that does not guarantee it is fixed.
Is the power loss constant or does you motor surge??? how does it idle and crank up???

 

[Bigal77fishing]

Re: 1982 v4 140 loss of power

Hi Thanks for all your helpful replies and sorry it has taken me so long to respond but it looks like i may have had a win with my outboard woes. Anyway for those that are interested i took my boat to my usual mechanic and he said he also found water in the carbs ? took the boat down the river with the young bloke from the workshop with a heap of tools etc. Fired the old girl up and away we went, gave it a bootful and what do you know i have all my H.P back, smiles allround obviously. Back at the ramp the pig of a thing wouldnt shut down, running on, oh bugger. I instantly say to the young outboard mechanic what do you think. A blank look on his face is all he could offer, so we go back to the wshop and i say to the guy who actually worked on the engine "well done i have all the power back but its still running on what did you do". His reply was, " well to tell you the truth there was very little water in the carbs i adjusted the floats as they were way out " Oh i see dont realy want to bag the other mech who apparrently found water as well, no probs i can live with that. So i decide to take a punt and replace the ignition switch in the foward controls, fire it up and get it warm and then switch it off and it still runs on. Finally i get another oppurtunity to have a play yesterday and it appears that the other power pack is now failing to shut one side of the engine down and iam guessing this is due to the original ignition switch being faulty which is what one of the helpful members suggested could be the cause. Moral of the story, IT IS HARD TO FIND GOOD HELP whats worse is these apparently skilled tradespeople charge quite high rates and it seems they rarely get things sorted first time round, this i can relate to as iam a telecummunications tehnician and intermittent faults are an everyday occurance in my job. Anyway it is off to the outboard wreckers tmrw to get another pack. And by the way did i mention it is now idling at about 1200 rpm on ear muffs and just over 1000 rpm in the water with exhaust pressure. Spoke to local mechanic and his response was replace the pack and bring it down , but we will need it for a couple of hours minimum. Is this true ? Is idle adjustment complex on my engine ? Thanks Alex

 

[emdsapmgr]

Re: 1982 v4 140 loss of power

I have seen run on caused by both a bad ignition switch and also a bad pack. Glad you got your run on issues solved. Your engine should idle between 650-750 in gear, idling while the boat is sitting at normal rest in the water. You can't set it while idling on the trailer. The idle is not adjusted by the carbs, as the carb idle jets are fixed on that engine. You set the idle by decreasing the idle timing, with the big screw on the spark advance lever. Disconnect the throttle cable at the engine when setting the idle timing, then reconnect when set properly. If you can't get it to idle that low, perhaps due to a lean sneeze or a miss, you may need to clean the idle circuits in both carbs.

 

[SparkieBoat]

Re: 1982 v4 140 loss of power

i had a run on problem with a 79 V-4 once and it was the ground wire from the controls to the engine had come loose, key shocked the **** out of me too.