Suzuki 2009 DF100 won't rev out

[borryking]

I have had an issue occur a few times on my DF100 (38hrs) as follows:

First instance - After being anchored for a while I start the engine then proceed to power up onto the plane. The first time I had four on board with two at the rear and the engine wouldn't rev past 4500rpm (with throttle in full position) and wouldn't get on the plane. It felt as though there was an anchor tied off at the stern. The engine was knocked back to neutral and it then stalled. Restarted, dropped the trim tabs, moved the guys forward and it was fine (i.e. would rev out).

Second instance - had been fishing at anchor with only two on board and proceeded to take off. The boat would get on the plane (much lighter this time) but again would not rev past 4500rpm with throttle in the full position. The maximum speed I could get was 23kts. We stopped and checked the prop for weed (none found) then restarted and took off again. Engine ran fine and would rev out to WOT (6100rpm) and get 33kts.

Third instance - As per first instance and had engine cut out completely. Ran fine when started back up.

Both times the revs stuck at roughly the same speed despite the throttle being pinned to the stop. A restart in all cases has cleared the problem. There is no other misfiring or rough running; it just doesn't get full power. There is no water in the water separator and fresh fuel was put in the tank both times (premium ULP). No fault codes are being raised.

[larrysuzuki]

No power on first restart

I would start up engine and let idle for a fee minutes be for going full throttle. Also when you go to stop and shut off engine let it run for a fee minutes to cool down. Sounds like the fuel is getting to hot and boiling.

[borryking]

Thanks for the reply Larry. Each time I take off the engine has been idling for a number of minutes. I have a drum anchor winch and start the engine prior to retrieving the anchor; idling forwards as the rope is coming up. When taking off I thottle on only as much as needed to get on the plane then back off. Similarly, the engine idles for a few minutes (probably longer) as I idle around to position on the gps waypoint and during deploy of the anchor. The engine is then shut down after the anchor has set. Both batteries are switched on, but not paralleled. The winch runs off the house battery only.

[mitch]

where are you what is the water temp is the water tell tale strong is there a good flow through the fuel cooler ?

[borryking]

Hi Mitch, I am in South Australia and the water surface temperature is about 14-15 degrees C. The telltale is flowing strongly, but am not sure how to check the fuel cooler.
Cheers Mike

[mitch]

ok so water temp is not an issue
on the fuel cooler number 10 in break down
Suzuki Marine Outboard Parts 2009 DF100 FUEL INJECTOR Diagram
there are some small water pipes remove one of them with motor running and see if you have a good water flow . NOT THE FUEL PIPE ON THE TOP AND BOTTOM OF COOLER the small ones in the side .

[borryking]

Thanks Mitch, will give it a try tonight and let you know how I go.

[borryking]

Hi Mitch, last night I took the covers and ran the test you asked. One thing that I did notice prior to testing was that the discharge hose from the fuel cooler was pinched quite badly by a plastic clamp:





I relocated the clamp and eliminated the pinch:

[borryking]

To check to see if the restriction was having an impact on flow I tested by removing the discharge hose where it re-enters the block:



Hopefully the video works, it shows a good stream of water exiting the pipe. It doesn't seem that the restriction had a large impact on flow, but I fixed it anyway.

One thing that I did notice was that the main fuel hose entering the engine was quite badly pinched where it goes around the throttle linkages:





Not sure if this is how it comes from the factory or whether it is an installation issue, but the dog leg around the linkages seems very extreme. I haven't done anything about this yet as I ran out of time (and the conduit was very hard to get off the engine end). Is there a better way of routing this fuel hose? Alternatively is there a better sheath that I can use around it to stop it pinching in this area?

Between the two hose restrictions it seems I could be on the right path.

[mitch]

so you had a good cooling flow but the pinching of the fuel line might be something,that is a rigging set up by the boat shop .

no tight bends in fuel line where it comes through the hull ?


this engine will still have a lot of warranty on it. But more that likely if it is a fuel problem you are on your own unless it has something to do with the rigging set up

had another look at your pics that fuel hose does not look right .

[borryking]

Yeah, it doesn't look quite right does it? You wouldn't happen to have any pictures showing a better route at all? Seems like I should take it back to the dealer that fitted it to get him to sort it out. I had run my nmea cable through there also, but the fuel line route never changed. There must be a better way of running it.....

[borryking]

I have located the cause of my problem, and it actually had nothing to do with the engine at all. After checking all fuel/vent items I dropped it off to my mechanic who still could find nothing wrong. I had exhausted all avenues so decided to disconnect the NMEA / SMIS network from the motor. Eight or nine trips later and it hasn't missed a beat. The network was giving the engine bad data or back feeding power somehow.

Brownspoint have given me software updates to try, which I will do soon. Failing that, I will need to try a new engine interface cable as they have been known to be faulty on occasion.