Help. Motor experiencing the following problem Starts great, idles smooth, and runs very smooth and normal up to 2800-2900 RPM then starts "missing" Changed spark plugs, all fuel filters, and put on new OEM gas line from portable tanks. Didn't help. Am now going to use fresh tank of gas...what I was using was fresh but could have had some residual gas or moisture from last year. Any thoughts would be appreciated. Motor is 2002 model with only about 200 hours on it.
ModEdit: Moving to Perf/Tuning ~fc
Trouble w/Suzuki DF-50
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Ric K
- Deckhand
- Posts: 42
- Joined: Fri Dec 09, 2005 9:38 pm
- Location: San Marcos CA, '02 X, "BUENA SUERTE". 60 HP Mercury
Problems with Suzuki DF50
Mssydnie,
Your problem sounds like the rev limiter is keeping your engine below 3000 rpm, this is generaly caused by an overheating situation. Check for water flow through the telltale ( peehole).
1) bad waterpump impeller
2) bad thermostat
3) bad manifold heat sensor
With 200 hrs if you have'nt replaced any of the above, in that order, I would be amazed if you don't have a cooling problem.
I have 300 hrs on my 2001 Suzy 50, and I replaced all 3 items during the 1st 200hrs, the last 100 hrs have been wonderful. I replace my impeller every 100 hrs.
Ric
Your problem sounds like the rev limiter is keeping your engine below 3000 rpm, this is generaly caused by an overheating situation. Check for water flow through the telltale ( peehole).
1) bad waterpump impeller
2) bad thermostat
3) bad manifold heat sensor
With 200 hrs if you have'nt replaced any of the above, in that order, I would be amazed if you don't have a cooling problem.
I have 300 hrs on my 2001 Suzy 50, and I replaced all 3 items during the 1st 200hrs, the last 100 hrs have been wonderful. I replace my impeller every 100 hrs.
Ric
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Frank C
Re: Trouble w/Suzuki DF-50
It sounds exactly like fuel starvation to me. When engine speed gets over 3000 rpms, the fuel pump's suction becomes significant. It might be that the fuel tank's internal pickup tube is leaking air. (It can't be carbs ... Suzuki doesn't use 'em on any outboards >25hp.)mssydnie wrote: ... very smooth and normal up to 2800-2900 RPM then starts "missing" ...
Changed spark plugs, all fuel filters, and put on new OEM gas line from portable tanks. Didn't help ...
The "quick test" is to dunk the bare end of fuel hose right into the gasoline. It's best to have a Mate handle the fuel hose while you drive. If you can get past 3000 rpms this way, you've found an internal air leak within the fuel tank. I discovered this problem in my OMC Duratanks - both of 'em. The fix is time consuming, but not difficult.
If that doesn't solve the problem, trace the entire fuel delivery system looking for any source of air leakage. You can wrap fittings with electrical tape (in test mode), but that won't work at the fuel tank.
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Catigale
- Site Admin
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Im still not quite sure what you mean here...do you mean its an irregular miss?? My Bigfoot (Merc 50 HP EFI) will start running roughly when you run the tank out, if you pull it back to idle it will idle smoothly long enough to swap fuel tanks. You cant miss the rough running mode unless you really are out of touch with your senses...then starts "missing" like a car engine.
Conversely, if you take a spark plug wire off an engine and run it up, it can hard to tell its missing on one cylinder if you dont know what to listen for since the miss is 'constant'
Suzuki DF50 300rpm rev limiter
Running great up to 3000 RPMs then missing is exactly how the rev limiter works.
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When the RPMs in overheat condition reach 3000, the engine computer decides you no longer need a spark or fuel. The engine begins to slow down, the computer notices less than 3000 RPM, so gives back spark and fuel, then if you are asking for more power it will again exceed 3000 RPM and you get a feeling like a missing engine.
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A test: try and run as close to 3000 RPM without hitting 3000RPM and if it runs great, your problem is that the computer thinks your engine is in need of rev limiting. If the engine is not warmed up yet, you have a sensor problem or a computer problem.
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When the RPMs in overheat condition reach 3000, the engine computer decides you no longer need a spark or fuel. The engine begins to slow down, the computer notices less than 3000 RPM, so gives back spark and fuel, then if you are asking for more power it will again exceed 3000 RPM and you get a feeling like a missing engine.
..
A test: try and run as close to 3000 RPM without hitting 3000RPM and if it runs great, your problem is that the computer thinks your engine is in need of rev limiting. If the engine is not warmed up yet, you have a sensor problem or a computer problem.
df-50
Mine did that. Took it to the shop. They changed fuel filter, water separater. Cleaned fuel injectors. Gas tank had water in it. So did the injectors. Ran good ever since.
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nemo
- Engineer
- Posts: 143
- Joined: Sun Mar 20, 2005 4:39 pm
- Location: Aloha, Oregon, '05 M, Suz70, "Nemo"
Re: Trouble w/Suzuki DF-50
My Suzuki DF70 has this same problem right now.
It started out last year with an occasional miss only at full throttle and only for the first few minutes of running. Then it would clean up and run just fine for the rest of the day. Over time the miss would happen throughout the day, but only ocassionally and only at full throttle. Then this last time it would miss the whole time at full throttle, and never ramp up RPMs. Runs fine at lower RPMs.
Called our local Suzuki dealer and he thinks maybe water is in the fuel system, or maybe a bad plug. Anyway, I'm sure I don't have more than 50 hrs tops on this engine. They said to bring it in the morning so will do, and will report back what it ends up being.
By the way, he said he always recommends installing a water separator on the fuel system for this engine and they don't come with it by default. I don't even know if mine came with one or not (haven't been out there to look since talking to the guy). But if I don't have one, I will after tomorrow.
It started out last year with an occasional miss only at full throttle and only for the first few minutes of running. Then it would clean up and run just fine for the rest of the day. Over time the miss would happen throughout the day, but only ocassionally and only at full throttle. Then this last time it would miss the whole time at full throttle, and never ramp up RPMs. Runs fine at lower RPMs.
Called our local Suzuki dealer and he thinks maybe water is in the fuel system, or maybe a bad plug. Anyway, I'm sure I don't have more than 50 hrs tops on this engine. They said to bring it in the morning so will do, and will report back what it ends up being.
By the way, he said he always recommends installing a water separator on the fuel system for this engine and they don't come with it by default. I don't even know if mine came with one or not (haven't been out there to look since talking to the guy). But if I don't have one, I will after tomorrow.
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nemo
- Engineer
- Posts: 143
- Joined: Sun Mar 20, 2005 4:39 pm
- Location: Aloha, Oregon, '05 M, Suz70, "Nemo"
Re: Trouble w/Suzuki DF-50
I guess my problem was different, although symptoms seemed the same. Turns out I had a bad sparkplug - it's been deteriorating over time. A new set of plugs was all I ended up doing. No fuel/water separator as there's really not a good place to mount one.
Had to take the boat out for a test drive this afternoon, all in the spirit of checking it out to make sure it was all fixed, of course. Took 2 of my kids up to Hagg Lake for about 3 hrs of wake-boarding, knee-boarding and a bit of tubing, mostly wake-boarding - and had a blast. Left the mast and boom at home so set up, launch and recovery were a snap. Engine ran like new - never missed a beat.
Had to take the boat out for a test drive this afternoon, all in the spirit of checking it out to make sure it was all fixed, of course. Took 2 of my kids up to Hagg Lake for about 3 hrs of wake-boarding, knee-boarding and a bit of tubing, mostly wake-boarding - and had a blast. Left the mast and boom at home so set up, launch and recovery were a snap. Engine ran like new - never missed a beat.
Re: Trouble w/Suzuki DF-50
Hello to all.
Please tell me if you solved the problem of mssydnie.
I have the same problem Motor starts grate, idles smooth, and runs very smooth and normal up to 2800-2900 RPM then starts the problems.
The last time I was on the boat I had this problem, after a minute or two the motor started working without problems (up to 5500 RPM).
If you solved the problem please tell me what to do. (was water in fuel?)
Please tell me if you solved the problem of mssydnie.
I have the same problem Motor starts grate, idles smooth, and runs very smooth and normal up to 2800-2900 RPM then starts the problems.
The last time I was on the boat I had this problem, after a minute or two the motor started working without problems (up to 5500 RPM).
If you solved the problem please tell me what to do. (was water in fuel?)