suzuki 85 hp problem

N

neville rourke

New member
Good day guys,
Firstly thank you to all the guys who contribute to making this forum so brilliant.

I have a duck with an 85 hp suzuki motor. The motor is an old one as seen in the photo. I recently had the motor serviced at a reputable East Rand boating company. On our first weekend away the motor ran fine. Started the motor twice in the next month, and on our next outing the drama started.

After launching the motor started easily and ran like a dream, ran brilliantly until I decided to stop. I cut the motor and a few minutes later I restarted. Engaged gear and as I pushed the handle forward for movement the motor cut out. This happened repeatedly while the motor was hot (running temp).

So a quick trip back to the boating company who could not find the fault before our holiday began. So the duck stays at home (what disappointment). On return my friend and I get to work.

This is what we have looked at:
1. The fuel line from the tank to the carbs. ALL LOOKS GOOD.
2. The carbs striped, cleaned, float levels the lot. ALL LOOKS GOOD.
3. Take off the fly wheel, remove the magneto and send it in to be tested. We told it is working fine on their machines. WE STILL SUSPECT THIS PART?
4. We do a compression test. ALL GOOD THERE
5. Along the way we also changed the spark plugs, the fuel, the fuel filter and anything else we could think of.

So now I am stuck in that I have no idea of what to look at next. Has anybody had this problem before? Any suggestions on what I can do would be greatly appreciated
:?
 

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I

IWyk

Sealiner
Just to clarify. It starts fine and sounds ok but as soon as you put it in gear it cuts out?

Does it do the same thing when you run it on the bunny ears?
 
I

IWyk

Sealiner
If it starts and idles fine but cuts out when you put it in gear. I think you have to to also run through the electricals.

I would check all the main connections coming from the stator assembly and the timer base assembly(both are under the flywheel and if you follow the two bundles of wires you will get to the connections.

Also check bolts holding coils etc. in place, the ones that have stainless steel plates and lugs with wires attached are most important as they serve as earths which could cause problems.

When you put the motor in gear the two main mechanical things that happen on the engine is that the gear shifter puts the motor in gear and the throttle control pushes the carburetor levers open to accelerate. Often after engines have been worked on wires are put back in wrong positions and get chaffed by the control arms.

Take the engine cover off, without starting the engine have somebody engage the gear and push the throttle lever all the way forward. Do this a few times and make sure that no wires are being interfered with by the gear shifter/selector and/or the throttle control.

Not sure on year model, if you do not come right send the engine number, it could make the trouble shooting easier.

Hope that helps..
 
N

neville rourke

New member
Sorry, when cold she goes fine as long as you don't stop. Once she is warm and you stop. She will start and idle but cuts as soon as you accelerate
 
I

IWyk

Sealiner
Have you put it in gear while on the bunny ears? and pushed the throttle forward and it accelerates fine? or does it cut out when you do that?
 
I

IWyk

Sealiner
Not sure on you exact model but with these symptoms you need to check the following.

Engine cover off, do not start. Have somebody pump the fuel ball hard and keep pumping. Check the fuel line to the fuel pump, check VERY carefully all around the fuel pump and the from there to the carbs. You have most probably got a small hairline crack on the fuel pump housing somewhere. Need to check properly as it may be small.

If you find any damp spot wipe it with toilet paper and keep pumping, if it gets moist again that is the spot. When the motor runs you will never find the wet spot as it suck air and not push fuel out.

Will not bother the engine at idle only when you want to accelerate.
 
I

IWyk

Sealiner
When the motor idles on the ears and gets put in gear there is no torque on the prop but when in the water there is a lot of torque on the prop.

With the hairline crack at idle the pump sucks in air but not enough to affect the engine at idle, however when you try to accelerate in the water it will cut out. When you then start it in neutral it will start.

When you try to accelerate fast in the water instead of injecting petrol into the carb you are injecting air and it stalls.

You can try and accelerate very slowly and it may not cut out, this will confirm that it is sucking air. However if the crack is bigger it will cut out even if you just put it in gear.

Please bear in mind that we are talking about minute cracking and probably not visible to the naked eye, therefore you need to check as I explained with pumping the ball and using toilet paper.

Good luck and let us know how it goes.
 
I

IWyk

Sealiner
There should be two pipes from the fuel pump to each carb. One is the main fuel supply that goes to the needle and seat and the other smaller one goes to the top of each carb(again depending on engine model). This smaller pipe might be blocked. It delivers a extra squirt of petrol on initial acceleration. Does not often block but they may be all interlinked and the supply pipe may be blocked Make sure the and the small jets they lead to are clean and open.
 
I

IWyk

Sealiner
Seen this before sucking air most probably hairline crack on fuel pump. Normally on older engines and especially when the y are hot and not when cold. Try and follow the steps as above but look closely as it is small as mentioned. Can be fixed with epoxy or superglue and powder,
 
I

IWyk

Sealiner
Chat again tomorrow I am out of country and need to get up at 2h30 SA time good luck. Cheers for now.
 
N

neville rourke

New member
We did look at the fuel pump but we will do the test with the engine off and the toilet paper. I also wondered if the fuel line might be damaged on the inside somewhere so that a small piece of plastic or rubber might be closing the line and blocking the fuel.
 
I

IWyk

Sealiner
neville rourke wrote:
We did look at the fuel pump but we will do the test with the engine off and the toilet paper. I also wondered if the fuel line might be damaged on the inside somewhere so that a small piece of plastic or rubber might be closing the line and blocking the fuel.
Click to expand...

Highly unlikely. To check, remove fuel line from engine, use a punch or similar to bush the ball bearing in and pump to check if line is clear.
 
MichaelK

MichaelK

Sealiner
I had that problem with my old 40hp yamaha 2 strokes. It was eventually identified as a fuel starvation problem in the carbs. The injectors were cleaned and a new phlange placed in the fuel pump. Worked perfectly after that
 
I

IWyk

Sealiner
MichaelK wrote:
I had that problem with my old 40hp yamaha 2 strokes. It was eventually identified as a fuel starvation problem in the carbs. The injectors were cleaned and a new phlange placed in the fuel pump. Worked perfectly after that
Click to expand...

You mention "40 Hp Yamaha 2 strokes" so I presume it was both? If so, would not have been, both motors(4 or 6 carbs) at the same time, was not a carb problem but as stated fuel pump problem. Jets cannot cause a fuel starvation problem(unless completely blocked but then the engine wont start, faulty fuel pump for sure. They probably made a few bob on the jets though.

Carbs don't have injectors I think you mean jets? They probably changed a diaphragm on the fuel pump.

I am convinced Neville has a problem on the fuel pump, lets hope he gets it sorted.

Cheers have a good weekend.
 
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