Suzuki DF 6 Backfire when starting

[W77]

Last year I bought an Avon inflatable and a Suzuki df6 outboard. Managed to clean up the oars and floor boards in the winter.

So first nice weather of the year i filled a clean wheely bin checked everything over and gave the Suzuki a try.
It backfires savagely when I pull the chord and after some profanity I tried an old favourite holts brake cleaner tiny squirt in the intake and it runs nicely.

But let it cool and it is back to square one.
I suspect a carburettor rebuild is necessary, just wondered if anyone else has experienced this?


The water trickle seemed to slow right down after running for 10 mins so I think an overhaul of the pump would be a smart move.

Also noticed an oily tide line in the bin, but the engine has been moved around and hasn't run for a while so may be needs some running looked at the valves and they look OK and compression feels OK (not actually measured just thumb over spark plug hole)

Hope to get it all sorted by late spring time.

[beamishken]

Originally Posted by W77

Last year I bought an Avon inflatable and a Suzuki df6 outboard. Managed to clean up the oars and floor boards in the winter.

So first nice weather of the year i filled a clean wheely bin checked everything over and gave the Suzuki a try.
It backfires savagely when I pull the chord and after some profanity I tried an old favourite holts brake cleaner tiny squirt in the intake and it runs nicely.

But let it cool and it is back to square one.
I suspect a carburettor rebuild is necessary, just wondered if anyone else has experienced this?


The water trickle seemed to slow right down after running for 10 mins so I think an overhaul of the pump would be a smart move.

Also noticed an oily tide line in the bin, but the engine has been moved around and hasn't run for a while so may be needs some running looked at the valves and they look OK and compression feels OK (not actually measured just thumb over spark plug hole)

Hope to get it all sorted by late spring time.

The tel tale slowing after a while could be a sign of salt/corrosion build up coming loose & partially blocking the tel tale hole, some strimmer line or similar up the tel tale hole whilst running may work it free.
Re the start issue the backfire isn't what you'd expect but if it runs on brake clean then it sounds like a fuel issue. Small 4 strokes are quite bad for carbs blocking due to the tiny orifices getting gummed up. A strip & clean with brake clean or idealy a couple of cycles in an ultrasonic bath usually does the trick but occasionally only a new carb will sort the issue.

[W77]

My thoughts are blocked idle jet and first thing I intend to do is strip and clean the carburettor i have used an ultrasonic cleaner previously for the same job, I put the components in a glass jar and added brake cleaner then put the jar into the water in the cleaner.
I've been looking for carburettor overhaul kits but struggling to find one, I thought they would be easier to find.
I will try to poke out the tell tail hole when I get it running and see how it goes, water pump overhaul kits are not dear and easily available.

[Steve509926]

Originally Posted by W77

I've been looking for carburettor overhaul kits but struggling to find one, I thought they would be easier to find.

Give SSI Marine a call. Has so much more stock than what is on their website.

https://ssimarine.co.uk/

[W77]

Thanks I'll contact them see if they can help

[W77]

It's a bit cold here but I decided to have a look at the carburettor.

Took it off and opened up the float chamber, immediately I think I found the prime suspect, bottom of the float chamber has quite a bit of black sludge in there. Considering that this is turning up downstream of the fuel filter then it's origin is limited.
Could it be that it has had some E10 petrol through the black rubber hose which has broken down the rubber?

I will order some new fuel hose and a little inline filter and some new clips then replace the whole line with more up to date stuff.
Then clean out the carb in US cleaner and blow with air.
Hope this will sort it.

[W77]

Stripped the carb completely and gave it a good session in the ultrasonic cleaner, unfortunately the float chamber gasket was split, suspect it has been done previously and gummed in need to get a replacement.
Put things back and decided to give it another wheely bin cruse.
Flicked it over with no spark plug to fill the carb up, then tried it it backfired savagely managed to start it and it runs nicely, will tick over very slowly. poked out the water tell tale and it is flowing very well.
I stopped the motor and went to re start but rather than pulling the chord slowly until it hits the compression then yanking it I just gave a hard pull, it fired up instantly.

I think pulling the recoil rope from a slack position gives it chance to pick up speed before hitting the compression and the inertia carries it straight over the compression rater than bouncing off it .
Least I hope that's it will know better next time.