Suzuki 70 hp motor problems

[iufan73]

I have a 1998 70 hp Suzuki motor on a 19 ft pontoon boat. I have had the boat 2 years now. Last year it ran great. This year I am having a lot of issues with the motor. It dies within 5 seconds of starting. It takes a while but I usually can get it started (10 - 15 tries). Once started it runs really rough. At low speeds the rpms will jump between 800 and 1400 rpms. Then it is only topping out at 4000 rpms and runs really rough at that speed also. Last year it was running a lot faster. I have run a number of bottles of seaform and injector cleaners and nothing seems to work. I have contacted the guy that winterized my boat and he just keeps telling me to use another can of seafoam. Any suggestions on what the problem is since he won't come out and look? Any help would be apprecaited.

 

[JB]

Re: Suzuki 70 hp motor problems

Is this a DF70 EFI 4 stroke? Or is it a 2 stroke?

Do you have a Service Manual?

Continuing to try to run the engine in this condition is likely to destroy it. Don't. It is likely to be fuel delivery. Many possible causes. You need to give us more info.

Don't try to work on it without the Manual.

 

[iufan73]

Re: Suzuki 70 hp motor problems

Yes it is a DF70 4 stroke. I do have a owners manual. Is that the same as the service manual? I usually let people with more experience work on things like this. I just wanted to get a second opinion because the guy that normally works on my boat is telling me just to run Sea Foam through it which isn't helping. I just wanted to know if this is something I could fix or if I need to call somebody else.

 

[JB]

Re: Suzuki 70 hp motor problems

I think you need the Service Manual.

It will give you guidance in troubleshooting the fuel pumps, vapor seperators and filters. I suspect that is where your trouble lies.

If your wrench is not certified on the four stroke Suzis, don't take it there.

DF70s should start at the turn of the key just like an EFI car.

I gave my Manual to the buyer of my boat, so I don't have the ability to step you through it.

 

[iufan73]

Re: Suzuki 70 hp motor problems

Thanks JB for your advice. I just ordered the service manual. I hope this works.

 

[manitoba1]

Re: Suzuki 70 hp motor problems

My DF70 started acting up this spring. The engine would stall at times stumble but this was intermittant. Drained the fuel and tried seafoam and injector cleaner and still had the problem. Changed the plugs which still looked excellent but did it anyway and the problems was solved. My DF70 runs like a clock again.
Try the plugs if you haven't changed them.

 

[pontooning]

Re: Suzuki 70 hp motor problems

Try some fuel injector cleaner as your high jets could be clogged. My 4-Stroke was run on my 24' pontoon and frankly, I didn't run it fast and hard often enough and the deal chuckled at me when I took it in for service and told me that I had over 100 hours at 2mph.

The motor is 7 years old - it runs so clean that it looks brand new - I found that beginning of each season I run some injector cleaner and have had no problems.

my2cents

 

[JB]

Re: Suzuki 70 hp motor problems

This thread is over 2 years old, 'tooning.

 

[16 dancer]

Re: Suzuki 70 hp motor problems

I have a 1998 70 hp Suzuki motor on a 19 ft pontoon boat. I have had the boat 2 years now. Last year it ran great. This year I am having a lot of issues with the motor. It dies within 5 seconds of starting. It takes a while but I usually can get it started (10 - 15 tries). Once started it runs really rough. At low speeds the rpms will jump between 800 and 1400 rpms. Then it is only topping out at 4000 rpms and runs really rough at that speed also. Last year it was running a lot faster. I have run a number of bottles of seaform and injector cleaners and nothing seems to work. I have contacted the guy that winterized my boat and he just keeps telling me to use another can of seafoam. Any suggestions on what the problem is since he won't come out and look? Any help would be apprecaited.

I would like to know if you ever resolved this problem because we are having a very similar problem. We have a 70 hp on a 19ft corolina skiff. We can start the motor and it runs for about 15 minutes. It actually runs very smoothly, but once it cuts off, we can not start it again. This has happend in the past, and then it just corrected itself. But we have had it out of the water now for over a month and can not solve the problem. Let me know what you found out.

 

[16 dancer]

Re: Suzuki 70 hp motor problems

I would like to know if you ever solved this program. We also have a 1998 70 hp on a 19ft skiff. The motor will start and run for a short period. The motor actually runs well. It cuts off and we can not get it started again. We have been trouble shooting for over a month. I would appreciate any information that you came up with.