Suzuki DF50 stalls after 100yds running

[patpat]

My Suzuki DF50 runs great most of the time. However, very often after being run for a mile or so, shutting down for an hour or so then restarting it will start great, get up on plane quickly, then shut off after about 100 yds. No apparent reason. The primer bulb will be soft. I pump the bulb till firm and it will run fine till the next time it sits for awhile. Just had the 200 hr service performed. Engine was said to be working perfectly. This a problem that has appeared and disappeared several times before. Plugs were changed a few months ago. No change in the occurrence of the problem. Some days no problem. Some days it happens every time I sit a while and restart. Using high test gas and Yamaha gas additive. Ethanol free gas when I can get it. I put a clear plastic tube in my gas line and observed it for air bubbles. Did not see and air bubbles. (At home on muffs at 4k rpm) Thanks for your attention. patpat

[keakar]

next time it happens check the gas cap right away to see if it has formed a vaccum, it may be a faulty tank vent

[patpat]

Thanks for reply

Gas cap is always vented. I never close the vent. No vacuum. Other posts talk about vapor lock on larger engines. Could this be the problem?

[keakar]

well just because its set to be open doesnt mean it cant be internally clogged

next time it happens just unscrew the cap and see if its sucking air so you can rule it out.

vapor lock can be from a faulty tank vent or it can happen to a carburated engine if the carb vent gets blocked

[patpat]

Thanks again

I will check it next time out. Same problem with main and spare tanks so I doubt it but will try anything. Thanks again Pat

[keakar]

i would think so but the soft bulb indicates loss of fuel flow or air entering the fuel line. enough air bubbles in the line can cause it to starve for fuel and act the way you described.

if you can find a way to seal off both ends of the fuel line and pressurize it with air you can use soap bubbles to check for leaks or at least see if it looses pressure telling you to replace the fuel lines.

you can test the engine by using a portable tank with its own hose to test if it still happens, if not its a fuel line problem, if so its something under the cover. the spare tank may not change anything if its using the same fuel lines as the regular tank.

[captfrankie]

Same Problem

I've experienced the same problem a number of times over the years. Most recently this past weekend. I had an extremely hard time getting it restarted.That's why I'm here. My engine is a DF225. It is spring when it happens. Never Summer Fall or Winter. I was told it was water in the fuel. I will change my fuel/water seperator filter fill the tank and put some water dissipator.

[kevmat200]

suzuki df225 stalling

Ive been having the same problem with my suzuki df250 they replaced everthing in the fuel system didn't solve the problem, so they replaced the motor with df250 ss, been running great till this last weekend and it stalled 2 times, only 40 hrs . now they are telling me its a vapor lock issue with suzuki and their fix is to add an additional fuel pump. anyone heard of this fix?

[junglecat1953]

Df250

I am having the exact same problem but it only acts up when it's hot, never quits until after. It has run for a while. It sometimes will stall out several times at low rpm when coming into port. I have talked to dealers who say they aren't aware of the problem. I think it's a vapor lock issue, any help on this?

[Longrange1971]

I agree with the above. Back on my old 2 stroke I had same problem. After many days and hours of searching, I found a kinked Fuel line under the deck. New fuel line, All good

[Moonlighter]

I am having the exact same problem but it only acts up when it's hot, never quits until after. It has run for a while. It sometimes will stall out several times at low rpm when coming into port. I have talked to dealers who say they aren't aware of the problem. I think it's a vapor lock issue, any help on this?

May be as simple as the anti-syphon valve on your fuel tank. US boats all seem to have them fitted, but none here in Australia do. We had a similar stalling at low revs issue on my mates Seaswirl that was imported from US. Issue was reported on Striper website, so we did what they Recommended - we removed the antisyphon valve from the tank, and replaced it with a simple elbow fitting. Problem solved. 15 minute job.

The giveaway was that the primer bulb was soft when the engine stalled. We would be powering along, get to a fishing spot, come off the plane to idle up to the spot, engine would stall. Pump up bulb, restart, power away and it would be fine at cruise revs.

Even if this isnt your issue now, removing that antisyphon valve is removing a future problem. Not needed on outboard powered boats at all. Only required in US for inboards.

At the same time, i would not discount what the previous poster has suggested either. And, add to that - check your fuel lines from tank to filter to engine. Give them a squeeze and roll around - any that feel hard or crunchy should be replaced - ethanol in fuel can cause interior lining on hoses to deteriorate and cause blockages.

[tommybe1]

valve

What moon said, just fixed the same problem with my DF50 after all new filters, hours of troubleshooting, turned out to be the valve coming off the tank, had this yellow goo plugging it up, but sometimes would break loose i guess and run great, anyways hope you get yours fixed, runs great when its getting gas :-)