F-Ribs And Sibs - Inflatable Boat Community

Just a bit of a heads up for anyone that buys/owns a Suzuki DF9.9 - DF15.
There appears to be somewhat of an issue when slowly going up through the revs. As the carb swaps from idle to main jet, you get a very slight engine hiccup/pop back through the carb.
I had my outboard in at Pennine Marine (Skipton) for some other issues, the mechanic (John) went completely through the motor trying to eliminate this problem, Suzuki technical got involved too, but no fault was found. It appears to be somewhat of an inherent issue.
It certainly does not impair the running/performance of the motor, and i would say, unless you're mechanically minded, you probably won't even notice its there.
I’m a massive fan of Suzuki motors, In general, the build quality, weight reduction and reliability is second to none, it certainly hasn’t put me off buying or recommending their super light, quiet and highly fuel efficient engines.
I know a few folk with these outboards, all appear to have the same issue, although as stated, very minimal. The Suzuki DF9.9 / 15hp are very popular outboards, Most folk seem to keep them, once purchased. I looked for about 6 months before I found a tidy, well looked after one. They seem to be as rare as hens teeth.

TBH Martin this isn't the first time I've heard of this issue on many outboards including my own
To meet the current EU emissions standards many manufactures of outboards (also cars) have to run them as lean as they can to meet the criteria
Many alter the mixture settings following a 1st service to make the engine more user friendly (richen the mixture) because in the 'real world' the performance is unacceptable for the user
In fact my wifes 12 month diesel car has just been and had its first service and they informed her they've re-mapped it and needless to say it's a much better drive and now accelerates properly, which it didn't before but at a small loss of 1mpg on the computer reading
Glad yours is 'peachy' now, enjoy

Paul

Being relatively new to all this, I'm only familiar with the Suzuki to a degree.
Suzuki know about it on the smaller engines, but deny knowledge on the 9.9-15hp ones. They have limits for adjustment on the mixture, mines right to max without causing an over-run after throttle off.
It's certainly cured the problem and you wouldn't know about it if someone hadn't pointed it out.
It's still an outboard I'm delighted with, starts for nothing, uses very little fuel and is light enough and powerful enough for my needs with the 3.8 sib and the weight of four up.

Hi Martin

Useful to know thanks

Do you know if this problem affects the earlier carb models or the new efi models or both?

Mine is a 2011 and I'm having some trouble with it, sounds like it's back firing. It's just started happening following me cleaning out the carb after a blocked idle jet.

Thanks

Hi duggie, it's the carbvwrsion only buddy

Duggie12 wrote:Hi Martin

Useful to know thanks

Do you know if this problem affects the earlier carb models or the new efi models or both?

Mine is a 2011 and I'm having some trouble with it, sounds like it's back firing. It's just started happening following me cleaning out the carb after a blocked idle jet.

Thanks

The mixture could be a little lean, try adjusting it to run a little richer

Paul B wrote:

Duggie12 wrote:Hi Martin

Useful to know thanks

Do you know if this problem affects the earlier carb models or the new efi models or both?

Mine is a 2011 and I'm having some trouble with it, sounds like it's back firing. It's just started happening following me cleaning out the carb after a blocked idle jet.

Thanks

The mixture could be a little lean, try adjusting it to run a little richer

Agree with Paul's comments.
Set the idle speed, find your optimum mixture setting and you may well find a 1/4 to 1/2 turn of the mixture screw (to richen, usually screws out) will overcome the change over from the idler jet to accelerater/main jet during operation ...... hope my description makes sense.

Very good information!.
Us 2 Stokers, we just leave an oil slick in our wake, none of this EU emissions standards

James wrote:Very good information!.
Us 2 Stokers, we just leave an oil slick in our wake, none of this EU emissions standards

Yeah, but this comes with its own set of problems.
I recently came to be in possession of a mariner 9.9 that had been used on the Thames on a safety boat for a rowing club.
The engine it's self is in good nic, but I've never seen a stroker so oiled up!

Everyone knows two strokes hate being kept at tickover for long periods of time though...

If you are going to do a lot of boating on rivers where speed limits are in place, it's got to be 4 stroke all the way

And on this note, I have heard rumblings that they are trying to "restrict" the use of 2 strokes on rivers and inland waterways...

Adding to the great advice given, be sure to run the engine up warm before setting the idle & mixture. When you think you have it right, pull the killcord and ensure the motor stops immediately.
Setting it up to run right might result in the engine running on slightly after the kill..
it's finding that balance that's the hard part.