Suzuki 4 stroke problem

duggie12 · 31 May 2017, 16:59

Hi all, I was away on a trip using my suzuki df15 2010 model there. The engine won't idle or motor at low revs - it just cuts out. Otherwise runs fine. One of my friends I was with thought it was maybe a blocked pilot jet and a quick Google search suggests that as well.

I hadn't used the engine in a good while - over a year actually. But the fuel was fresh apart from about a 1/4 tank

Does anyone have any idea what the issue might be or any other things I can check before having a look at the jets? I was going to try and give the repair a bash myself first rather than putting it into the garage.

Cheers folks

Rover310 · 31 May 2017, 17:33

From what you're describing, 'won't idle or motor at low revs', I'd say the cause is almost certain to be a plugged up pilot jet... old fuel that has congealed will do that. No short cuts to correct that, just need to disassemble the carb and clean everything up. For plugged jets, I soak the jet in ammonia for about 10 - 15 minutes and then blow compressed air through it.

FYI, this thread should rightly have been started in the Engine & Prop forum. Perhaps a Mod or Admin will see it and move it for you.

Fenlander · 31 May 2017, 17:43

Agree with Rover310... from your description dirt or fuel deposits in the carb are the most likely problem so start there.

That's assuming at 2010 yours is a carb type not efi like the later ones.

duggie12 · 31 May 2017, 17:49

Thanks guys

Yes fenlander it's def the carb type. Fenlander I read your suzuki service post and you clearly know your way about suzukis. Is stripping a carb a job to be left for a mechanic do you think? I'm happy to give stuff a bash but I've no experience with this sort of thing.

Thanks

Fenlander · 31 May 2017, 18:18

Duggie if you are methodical a carb is not that complex. Take pictures as you dismantle to assist. My workshop manual is only for the efi models otherwise I'd have scanned a few pages for you.

Otherwise a source of what it might look like is here... Fig. 12 - Carburetor - Suzuki DF 15 Parts Listings - 2009 - S/N 01502F-980001 to 01502F-98XXXX

Not sure if that is your model though you'd have to check that.

Oh this looks like your OB manual (but double check)... see section 4.4 onwards re carb remove/strip.

https://www.maritimepropulsion.com/files/pdf/1001408

duggie12 · 31 May 2017, 18:21

Ah you're a good man fenlander thank you

I'll give it a bash!

One more question....as I'm researching it's being suggested that I should buy a carburettor service kit containing gaskets etc. Do you have any thoughts on that or do you think I can get away with skipping it?
Thanks

Fenlander · 31 May 2017, 18:39

Ahh the old shall I spend £45 (a guess) and do it properly with a complete kit... or will I get away with it using old gaskets?

I'm a bit of a by the book guy so would always at the very least use a new float bowl gasket and one to the inlet manifold... assuming they are available without the whole kit which may have many things that aren't essential.

duggie12 · 31 May 2017, 18:42

Haha yeah I know what you mean about that dilemma

Actually what puts me off more than spending the money is the faffing about finding the correct parts and ordering them!

Point taken though, I'll get the kit and do it properly - and thanks again

Rover310 · 01 June 2017, 04:05

Curious thing about some of these OEM carb kits is that they are often priced quite reasonably as compared to the sum total cost of the individual parts contained in the kit. I've noticed that's the case for my '91 Evinrude 6 hp, where the price of the individual bowl gasket is nearly half the price of the entire carb repair kit.

Even if some of the items in the full carb kit are not really in need of replacement at the time, it's always good to have those 'spare' parts on hand, verses the alternative of finding yourself needing one of those parts and not having it.

Erin · 01 June 2017, 09:24

Had something similar once on a Honda 50. Turned out the linkage to the choke had become disengaged and the choke was not coming off properly. Worth checking before dismantling too much.

Mikefule · 03 June 2017, 17:21

Always run the carb dry at the end of a trip. If you have a remote tank, disconnect it. If you have an integral tank, turn off the petrol tap. Let the engine run until it dies. Some outboards have a button that allows you to rev them faster in neutral to save time. I have sometimes gone a couple of seasons without touching an outboard only for it to start almost immediately, and to run smoothly. If you let fuel sit in the engine, it will leave deposits that may cause blockages.

duggie12 · 18 June 2017, 10:31

Thanks all for the help with this. Stripped carb down and the idle jet is blocked. Can't even blow through it. Away to get some carb cleaner today.
Fenlander you are right it wasn't too tricky to strip down. It looked more daunting than it was.
I've still to put it back together though!

Mikefule · 18 June 2017, 18:27

Quote:

Originally Posted by duggie12

Fenlander you are right it wasn't too tricky to strip down. It looked more daunting than it was.
I've still to put it back together though!

With any luck, you'll have enough parts left over at the end of the rebuild to start building a spare carb...

duggie12 · 18 June 2017, 18:34

I seem to have fixes one problem and created another. It now idles fine but it's running a bit rough at low revs and it's backfiring a bit as well. The joys!

Fenlander · 18 June 2017, 18:35

Have you not reset the idle mixture properly?? That can affect the transition from idle to low speed.

duggie12 · 18 June 2017, 18:37

Fenlander I just put it back together, I haven't adjusted anything. I didn't think I had to.
Do I?

Thanks

Fenlander · 18 June 2017, 19:00

When you've done anything to a carb the idle screw needs setting. It should be in that manual I linked. If that doesn't sort it the problem you have now could also be down to an air leak... particularly if you reused old gaskets.

Edit: Another thing that comes to mind... if the accelerator pump is not delivering fuel properly that could cause a hesitation going from idle to power.

duggie12 · 18 June 2017, 19:09

Cheers, I'll check it out - and I did re use the old gaskets
Something I noticed was that the gaskets seemed to have something like a glue or silicone on them - when renewing (even with new ones) do you have to use something like that to get a air proper seal?

Thanks

Fenlander · 18 June 2017, 19:12

Some new OE gaskets have a layer of set silicone bonded to the card/metal of the main gasket. But however they come I never add gasket "goo" to a carb. Shouldn't be needed and risks getting places it shouldn't be to block jets.

duggie12 · 18 June 2017, 19:28

Thanks - I'll let you know how I get on