Suzuki DT2 outboard won't start

[ronsurf]

Can any outboard wizards help with this? It has me baffled. I'm no stranger to 2 stroke engines as a Lambretta owner for 30 years, but this simple little outboard has me stumped.
It cut out a while ago, so I decided to strip to down and give it a good service.

I fitted new crank seals, new plug and fresh petrol. There's a good strong spark at the plug and I've even strobed it to check the timing. Seems all good to me. No go.

I stripped the carb down again and discovered the atomiser, which was a bit gunky. Thought I'd found the problem! Cleaned, reassembled, but no go. Not even a cough.

Stripped it down again for another check, Check the reeds were working and the seals were good. Still no go. There's only a ticker setting on the carb, so no mixture settings. there's so little to go wrong and so little to check! No response to easy start. No response to anything.

Now I'm completely baffled. I will say there doesn't seem to be much in the way of induction, but the piston is so small there may not be much anyway. I can hear the reeds fluttering occasionally.

I'm starting to wonder if there's no earth connection at the head - is that even possible?!

Any ideas gladly welcomed. I will state again that the spark is excellent, and it has compression.

 

[PlankWalker]

the spark is excellent, and it has compression.

Then its got to be the carburetor.

 

[anoccasionalyachtsman]

Is the plug wet after repeated (choked and throttle cracked open) attempted starts?

 

[VicS]

How "excellent" is the spark ?
One with CD ignition should give a spark which will jump 3/8" in free air. Older one with points should jump 1/4". Just checking at plug is not good enough .. Use an adjustable gap spark tester .. improvised if necessary.

Doubtful if the head would not be earthed back to the ignition coil but easy enough to check

What figure did you get for the compression ?

Fuel getting into carb ? level correct?

Have you tried spraying some fuel mix into the carb intake ? ( or even Easy start )

Mixture is adjusted by moving the clip up/ down on the metering needle

Service manual here:- Boatinfo - Suzuki 1988-2003 Service Manual Covers a lot of models though

 

[ronsurf]

Thanks for your suggestions, I've just had another go at it.

The plug is wet and I can hear the induction through the carb now I've taken the front panel/cover off.

I've reset the float height to 20mm as suggested in the book.

I pulled the plug out and laid it against the head (with the plug covering the hole) to check the spark and there was a spark, and the fuel did ignite. An actual bang!

Still won't fire though. I'm wondering if the timing is a bit too advanced. It is firing a bit early, but I'm not 100% sure where the timing marks are. That's my last idea.

 

[VicS]

Check the strength of the spark as I suggest . It may be good enough to jump a few thou on the plug when withdrawn but may not be good enough under compression.

You dont say if its points or cd ignition. ( Points before 1990 ITYWF) If its points the condenser would be suspect. If points have you checked, cleaned and reset them or replaced them

In either case inspect the condition of the coil

Timing is set by the flywheel position on the crankshaft .. Its keyed on so check the key. They can shear and allow the flywheel to move on the shaft if the flywheel retaining nut is not correctly torqued

If the plug is wet maybe the carb is flooding

 

[RichardS]

Get hold of a powerful hairdryer, or similar, and leaving it blowing on the cylinder head for 15 minutes and get it as hot as you can. Then squirt/pour a few mls of two stroke mixture directly into the air intake and try and start it.

If it bangs or spits but doesn't actually run, even for a second, then there is something wrong with the ignition timing. If it runs for a few seconds and sounds OK, then the carburation is wrong. You could keep chucking in fuel and keep starting it and see if the carb clears through.

Richard

 

[ronsurf]

Get hold of a powerful hairdryer, or similar, and leaving it blowing on the cylinder head for 15 minutes and get it as hot as you can. Then squirt/pour a few mls of two stroke mixture directly into the air intake and try and start it.

If it bangs or spits but doesn't actually run, even for a second, then there is something wrong with the ignition timing. If it runs for a few seconds and sounds OK, then the carburation is wrong. You could keep chucking in fuel and keep starting it and see if the carb clears through.

Richard

I did heat the head and combustion chamber, and even the plug but still absolutely nothing.
I'll take the flywheel off and adjust the timing, I think it may be a bit too advanced. It's about the only thing that was disturbed when I stripped it down, but I did put it back together on the marks I made.

Struggling to find a workshop manual to find out what the timing marks should be, though.

 

[Fantasie 19]

This any good?? Suspect it's not the whole manual but there nay be enough to get you going? Suzuki 2-15HP outboard motors Service Manual | Manualzz

 

[VicS]

I did heat the head and combustion chamber, and even the plug but still absolutely nothing.
I'll take the flywheel off and adjust the timing, I think it may be a bit too advanced. It's about the only thing that was disturbed when I stripped it down, but I did put it back together on the marks I made.
Struggling to find a workshop manual to find out what the timing marks should be, though.

I assume from what you have said that it is a points ignition system but you have not confirmed this or stated the year model. If it's a CD system I don't think there is any provision for adjusting the timing .

If so you will find the timing procedure described on pages 3-18 and 3-19 in the manual I gave you a link to, in #4 .
You will need a dial gauge and the means to mount it in the spark plug hole

 

[abrahamkou]

I own two of Suzuki DT2 motors, early 1980 models(This model is highly reliable in my experience). One has a lot of mileage on it and the other one not as much. What I found is that the one with high mileage tends to have cold-start problem if I use regular gas containing ethanol, but no problem if I use pure gas. Yet the one with low milage does not care regardless of what type of gas I use. I am not sure the exact cause, but gas with ethanol definitely is an issue. Maybe some expert here can explain better...

Incedently, one of the pure gas advantage (printed on the gas can) is "Provides easier, more dependable starts".

 

[QBhoy]

What’s the compression figure on it. These are literally about the most bombproof 2 stroke there is. I’d hang fire on timing etc until your sure about everything else. How’s the carb gasket ? I’d say you’d likely need to ultra sonic clean the carb too. Just to make sure.
domt suppose anyone has fitted an inline fuel filter to it and it’s the wrong way around ? Is the fuel shut off valve operating properly and not blocked ?
Defo do a compression test on her first off…just to rule out anything nasty

 

[ianat182]

You may have a blocked fuel filter- not in he feeding pipe , or tap , but in the fuel tank itself. My Suzuki had similar fuel flow problems- it may even be water in the tank that is the first fuel the carb receives after running the motor dry at final use last time - maybe wetting the plug- not fuel.

 

[abrahamkou]

You may have a blocked fuel filter- not in he feeding pipe , or tap , but in the fuel tank itself. My Suzuki had similar fuel flow problems- it may even be water in the tank that is the first fuel the carb receives after running the motor dry at final use last time - maybe wetting the plug- not fuel.

Thanks much for the input.
I tested this motor multiple times with different fuel ( including cleaned carb, change plug, making sure fuel line flow...) , and each time, the ethanol gas gave me cold-start difficulty (warm-start no problem). That's just my experience on this motor. I also tested the same on my other low mileage unit and did not see the same issue. Weird... But it is what I see.