Suzuki 150s won't go above idle

C

Captains Cat

New member
Have had this problem before. Last time, I replaced both fuel filters, drained the LP filter on the engines and eventually the problem was "solved".

The engines idle fine, run smoothly etc but when I open the throttle, they die (Both of them). I have used the boat a few times in the past two months and both engines ran fine at all speeds. Haven't used it in two weeks or so though and today, it recurred. Drained one Racor today, no water to speak of and drained the LP filter bowl under the hood. No water there, only a little gas. I did manage to get that engine running faster by starting it with about half throttle (in neutral) but it ran very rough and smoked some.

The fuel is non ethanol, put in last fall and treated with blue Stabil and Startron, probably 65 gallons or so in each tank.

I tried squeezing the primer bulbs (although weve been told by experts that it's not necessary with a FI engine), they get hard after a few squeezes.

Since it happens to both engines, and they have separate fuel systems, it almost has to be the fuel but I don't see any contamination, or water in the filters. To have the same mechanical thing happen to both engines at the same time is probably pretty remote. Don't know why they would idle fine but not throttle up if that's the case.

About the only thing I can think of doing now is getting someone out with a portable polishing system and completely cleaning both tanks but before I do that, I thought I'd ask the assembled expertise on this site.

I'm kind of at a standstill, any help would be appreciated!

Charlie
 
There are a lot of knowledgeable people on this site. However, I'd try asking a GOOD dealer near you. By a good dealer, I mean one who has a knowledgeable repair shop. Be careful not to screw up those motors.

they would have the diagnostic equipment to look inside the electronics.

Boris
 
Have you checked battery voltage and connections?
Maybe it is bad connections at the batteries on OB side? A little bit of corrosion on the terminal, battery nuts are not tight or a bad battery
m2cw
 
Interesting that both engines are affected. Could the issue be electronic?

Coming back from La Conner last week, we started our Suzuki 90 in the morning after sitting over night. The rev limit light illuminated and sounded a continuous beep. Turned it off and restarted, all seemed normal on the gauges, the rev limit light was dark and no beeping. Headed home, but once we got out of the channel, the engine refused to go over 3300 RPM. The manual mentions the system may prevent the engine from going over 3300 when the rev limit light illuminates.

We consulted Doug at Performance Marine. He suggested first checking the fuel filter for water and draining into a cup using the black valve at the base if necessary. We didn't see any water. Doug explained that the light blinks a code (similar to Morse code) and to note the number of short and long blinks, and whether any other lights are illuminated as well. The service manual provides a key as to the meaning of the code. We restarted the engine, but couldn't get the lights nor beep to reoccur. Next, he suggested resetting the engine by pushing the key in for 5 seconds to clear any settings that may have become stuck. He suspected that there may have been a glitch and for whatever reason the engine tripped and didn't reset.

For us, we didn't have to reset...the engine revved properly when we went back to test. Who knows, maybe we'd pushed the key in without realizing it when we were trying to check for the code.

Not sure if this helps your situation, but might be worth trying a reset.
 
Boris, thanks. No dealers at all near here (100mi.), there is one but he doesn't make house calls and doesn't have any diagnostic equipment.

Brent, I m sure it isn't the batteries or those connections. Nothing abnormal in the starting or house usage. And the batteries for p/s are independent. Chances of both at the same time, pretty remote.

Caipirinha, nothing out of the ordinary on the diagnostic lights. I have the full service manual with the codes and if they blink I'll check. I have drained both filters under the hood through the little black plug and changed/drained both racors. Neither one fills completely with fuel and that makes me suspect a flow restriction somewhere.

I called a local fuel polishing guy and he will come do both tanks with a portable unit for about $250. That's a last resort.

My next step is to take both turbine type fuel flow sensing units out to see if they may be clogged. The electronic flow indicators have been behaving erratically, they may have picked up some debris from tank bottom, although both at the same time, from separate tanks?

Still on the hunt.

Charlie
 
Are the fuel flow meters before or after the Racor filters?
Mine was before the filter and clogged the screen inside the meter. I bought a new one and installed it after the RACOR filter.
Problem solved
 
Charlie,
We have a fuel managment system which has an inline filter in front of the paddle wheel fuel monitering gizmo. The inline filter in front of the fuel managment gizmo keeps the fuel managment gizmo from getting loaded up with unwanted debris. This is all before our main fuel water separator. I carry a couple extra fuel hose barbs so I can bypass the whole inline filter and fuel managment gizmo so I can elimanate that as being a problem. This was recomended in the instructions that came with our Garmin fuel managment system. I would P.M. Mark at Wefing's those folks know Suzuki's stuff as well as anyone. Does Dr. Bob make house calls?
D.D.
 
Charlie-following up on Will-C's suggestion, hook up a 6 gallon aux. can directly to a motor and see if you can throttle up. If it works, $250 seems a reasonable price for onsite fuel polishing and tank cleaning. Good luck.

MartyP
 
Thought about doing that Marty. I have some tanks but need to look at the fittings. D.D., still memorizing the Post, will look at my system before the day is done!

Charlie
 
Have the internal fuel filters been changed or checked ? I seriously doubt polishing is the answer to the problem . There are a number of filters iside the cowl that need regular service by a technician. The high pressure fuel pumps do not like to sit and can sieze up and have screens in them as well . It might be time to look under the hoods .
Marc
 
Thanks Marc, hoped you would chime in. Have found/done the following so far.

Fuel system is set up to feed from tank, through the racor. In one case, the turbine for the fuel flow sender is next, then the primer bulb, to the engine. The other one has the primer bulb after the racor and then the sending unit.

I removed both sending units just now and the high speed problem(after some fits and starts appears to be gone.

I have previously changed both racor filters, they had some gunk in them.

I have drained both LP filters under the hood but have not changed the HP filters. The engines have only 220 hours on them, Marc should I change them anyway?

I suspect gunk in the tanks, Marc should I drop $250 on that just to be sure?

I intend to clean and blow out both sending units with LP air before I reinstall them.

Just glad to have found the immediate problem, thanks all for the help!

Charlie
 
Charlie , I would change the HP fuel filters as a function of time ,not engine hours . I couldnt hurt to check the tanks, but I wonder how much flow that the polisher can get to stir up debris at bottom of tank , fuel polishing is mostly a diesel thing to get bacteria and sludge . Not nearly as much of that in a gas tank ,unless it has a bunch of water and the racor will pick that up on the first bumpy day .If the fuel smells old , its a better investment to get rid of it and find fresh non etanol to treat and run. I would run a good dose of Yamaha Ring Free through your motors . Its a very effective and powerful detergent and is worth the expense . I put through my diesel truck and all of our rental boats get a dose every 5 or 10 tanks .
Marc
 
Thanks Marc.

To get rid of the fuel and replace, it'd cost a lot more than $250 but I'll forgo the polishing, I hear what you say about diesel. I'll run the ring free through there and do the HP filters. The engines are 2006 (you sold them to Dr. Bob) and if time does count, as you say, it's time.

Can I replace the HP filters without removing the Fuel Vapor Separator Set/High Pressure Fuel Pump? There are good instructions in the big service manual to do that and I see the HP filter but there are no instructions for doing that.

Charlie
 
I'm not sure where Cod Creek, Va is, but here's a Suzuki repair shop: Chesapeake Boat Basin
1686 Waverly Avenue
Kilmarnock, VA 22482

phone: 804-436-1234
toll-free: 877-270-3515

You could call them and talk to them Monday if it isn't fixed by then.

I know that changing the HP filter on a Honda 150 can lead to a cracked cover if you don't watch out.

Boris
 
Captains Cat":127apqjd said:
Have had this problem before. Last time, I replaced both fuel filters, drained the LP filter on the engines and eventually the problem was "solved".

The engines idle fine, run smoothly etc but when I open the throttle, they die (Both of them). I have used the boat a few times in the past two months and both engines ran fine at all speeds. Haven't used it in two weeks or so though and today, it recurred. Drained one Racor today, no water to speak of and drained the LP filter bowl under the hood. No water there, only a little gas. I did manage to get that engine running faster by starting it with about half throttle (in neutral) but it ran very rough and smoked some.

The fuel is non ethanol, put in last fall and treated with blue Stabil and Startron, probably 65 gallons or so in each tank.

I tried squeezing the primer bulbs (although weve been told by experts that it's not necessary with a FI engine), they get hard after a few squeezes.

Since it happens to both engines, and they have separate fuel systems, it almost has to be the fuel but I don't see any contamination, or water in the filters. To have the same mechanical thing happen to both engines at the same time is probably pretty remote. Don't know why they would idle fine but not throttle up if that's the case.

About the only thing I can think of doing now is getting someone out with a portable polishing system and completely cleaning both tanks but before I do that, I thought I'd ask the assembled expertise on this site.

I'm kind of at a standstill, any help would be appreciated!

Charlie
Click to expand...

I once had a bad fuel hose cause similar problems. Engine would idle fine, at part throttle the fuel pump would suck the line closed & stall the engine.
Have a good one :wink:
 
Sorry to hear of the problem. What is even more puzzling is that you have been running the boat regularly recently...

Whan I first got the boat there was a bad anti siphon valve. I replaced it. That was causing the same problem, but it would show up as a flat primer bulb. The Racors are before the senders, but the fuel can sit in the senders and cause problems. You have already checked out the lines for water. There didn't seem to be much water in the tank, since not in the racor or in water sep inside the cowl.

I think that you had plugged senders--maybe the turbines were not spinning? I also put Starton in the tank, as well as either Ring free or Seafoam.
 
Brent, you can't afford it and I won't sell it!

Removed both fuel flow turbines, now the stbd one runs fine and the port one still exhibits the same problem. Will remove the primer bulbs and see if they are plugged in any way. I suspect a bunch of crud somehow got past the Racors before I changed them. The LP filter on the port engine doesn't fill with fuel which indicates fuel starvation to me. I also treated the fuel with Startron and Blue Stabil the last time (fall of 11) I filled it.

Have new HP and LP filters coming from Wefings along with Yamaha Ring Free which Marc recommends (at a lower than Internet price I might add!). He doesn't recommend Seafoam, says its bad for the O2 sensors.

Will update as I find answers, thanks all!

Charlie
 
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