Suzuki DF140 Bogging Down at 2500 RPMs

I dont have a shop manual but did the high pressure filter have a gasket or O ring and was it replaced?

Fuel rail going to injectors can checked with fuel pressure guage
 
Another possibility

is the high pressure pump inside the VST has a filter or strainer and it may be blocking fuel similar to Yamaha motors

these are suggestions
 
You guys are amazing!

I've looked at the ASV but don't think I can get it out. I have the steering counsel on the deck and have far less room on the port side...plus, I'm a full sized man.

My current theory is clogged VST or a pin hole in a fuel line sucking in air.

I have decided to bring it into a pro for further inspection and repair.

I use the boat at a minimum twice a month, so I haven't used fuel additives. After talking to some more seasoned folks, I think that has been an error. Our gas in CA probably needs a little additive.

I have a date with a mechanic a week from today. I'll be counting down the days.

I will repost next steps. Thanks for all the input!
 
Yes, it is all but impossible to buy non ethanol fuel in CA--Maybe Aviation gas...about it.

I don't remember which side my bad ASV was, but my Moto was if you can see it, (even with a mirror) you can get it out...some how. My wife. has much thinner arms and hands than I do--and sometimes she can get into a narrow place and get a fitting loose. I just got rid of the anti siphon Valve.
 
Same here

If I can reach it then most likely can work on it or Admiral Patty is super handy, too. I am a lot more mobile after both hips replaced.

We had a similar issue on our Parker with Yamaha F225.

Checked everything including replacing high pressure pump filter in VST, new pickup tubes, removed ASV, removed and inspected fuel filter head, all filters, convert to Racor 2 micron filter and having the fuel injectors serviced at Flagship. Learned a lot. We didn’t identify any problem except the fuel hose in rigging tube going into motor has a sharp bend was kinking the inner hose and restricting fuel
. I bought a Yamaha fuel hose or pipe kit and the 90 degree bend area is a formed piece, and no issue to date. It costed 55 dollars including a new Yamaha dual valve primer bulb.


Post the answer.
 
Wefings
Dealer


Joined: 29 Nov 2005
Posts: 2079
City/Region: Panhandle
State or Province: FL
Photos: Cruise Ship #4
PostPosted: Sat Aug 10, 2019 10:22 pm Post subject: Reply with quote
Replace [or remove] the check valve on the fuel pickup fitting at the tank . They are a common problem .
Marc
 
One of the best diagnostic tools for possible fuel related problems is a portable fuel tank with independent fuel line.

Unclip the fuel line at the motor and hook up the portable tank, full of new fuel (don't forget to open the vent on the portable tank). If the problem persists, it's something on the motor side of the fuel connector (could be fuel system, electrical, mechanical, etc.). If the problem goes away, it's something on the fuel tank side of the connector (bad gas, pickup system, leaking/collapsed/pinched fuel line, etc.).
 
Hey guys

Thought I’d provide an update on my issue. I great appreciated the input.

It turns out that when my welder patched the hole caused by the corrosion issue, too much heat was applied to the block and warping occurred. Both exhaust and water were leaking due to this damage. I don’t understand why it took a year to show up in engine performance, but I do know my welder had little experience with this type of patch.

So, True North is getting a birthday present! The re-power is scheduled to be completed on the 5 year anniversary of when I acquired her. I went with the same engines (Suzuki DF140) after a lot of research and a few calls.

Can’t wait to get back on the water.
 
WOW, that was unexpected. Tough to find, good catch.

I would highly recommend using Stabil if: 1. You buy gas in California, 2. You cannot get absolutely for sure, non-ethanol gas, 3. You are not sure when you are going to run the boat next. and 4. You are going to let it sit for more than a month until you will be running the boat next.

Ethanol gas is your #1 boat motor system enemy. That is everything from the filler "O" ring, the filler hoses, the tank, and the hoses from the tank to engine, and then there is the seals, gaskets, O rings and tubing inside the engine OB cowl.

I'm not a mechanic so this is what I get from my mechanics. I have not had a problem with my outboards, not since I started using my boat.

Harvey
SleepyC :moon

1_10_2012_from_Canon_961.highlight.jpg
 
So I have 3.5 hours on the new engines...they are sexy! I've noticed a little less thrust so far. I use to plane at 3200 rom but now its taking 4000rpm. I do have my tanks topped off which is rare, so it could be weight and/or tight engine.

I have been adjusting my rpm up and down every couple minutes during early break in.

I kept my old props. Question - would other props work better with 2019 DF140s than 2007 DF140s?

I was very happy with my pre-repower performance. Its ok now, but was expecting better.

Could also be throttle cable adjustment.

Thoughts?
 
Props should be the same. Suzuki "Water Grip" props are apparently a bit more than just the hub. Something you might want to look at if the situation does not improve down the line. There is a lot of difference between the 150 and 140 (more than the nominal 10 hp would suggest). We used to cruise in the mid 20's at 3200 with the 150's. The 800 RPM is more than I would expect with just break-in--could be extra weight, or other issues, like bottom condition etc. You won't really know until you can do continuous WOT to test out what the full RPM and speed is.
 
Got past the 6 hr variable RMP time and opened them up. Very happy! I think the torque is a little different but my cruising speed is the same. It just feels different to me but its a sweet ride!
 
Back
Top