Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  Yamaha 50-HP 4-stroke: White Smoke and Rough Idle

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Yamaha 50-HP 4-stroke: White Smoke and Rough Idle
17 bodega posted 07-06-2004 07:08 PM ET (US)   Profile for 17 bodega   Send Email to 17 bodega  
I noticed the other day that my Yamaha 4-stroke 50-HP engine was producing white smoke a little more than normal. Generally it smokes when I'm coming off cruising speed and then left at idle. Then I also noticed the same day that it was running a bit rougher than normal and died once. After a few cranks it ran again but still sputters at idle. Is this normal?

It is a carburetor engine. I checked the oil and no problems with level or viscosity. It runs like butter on plane and cruising.

Any ideas? Anything to worry about?

Should I try some gas additive carb cleaner or any other product?

The engine has 412 hours on it.


elaelap posted 07-06-2004 07:22 PM ET (US)     Profile for elaelap  Send Email to elaelap     
YIKES! That motor never gave me a moment's concern for the 360+ hours I put on it in a year, Steve...certainly never died or sputtered at idle, almost always started with the first turn of the key, ran smooth and silent at cruising and trolling speeds, and the only 'smoke' I ever noticed was steam blowing off the frigid NorCal waters. Luckily you've still got about three and a half years on the extended warranty...get that sucker back to Guenter's as quick as you can, and remind them that they serviced the motor shortly before I traded it back to them, along with sweet old Loolee.


17 bodega posted 07-06-2004 08:20 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     

It's not an acute thing. I only noticed it yesterday in Tomales Bay during the foggy evening. It only stalled once, and it was a "restart", and once the gas got flowing again, it ran fine. it's always had a slight misfire at idle, and i'm wondering if it's just a "yamaha thing"

I'm actually thinking in terms of a fuel separator because of the warranty fine print. (".. water in fuel is not covered by warranty..")

I spoke to Steve, and then Margie at Guenters ... and they say that non catastrophic engine tweaking is not covered by the warranty (grrr) so I can get it looked at in 3 weeks. Sigh.

So in other words, I need to go out and blow it up in order to get it worked on gratis!!!

2manyboats posted 07-06-2004 08:40 PM ET (US)     Profile for 2manyboats  Send Email to 2manyboats     
how old are the spark plugs?
Clark Roberts posted 07-07-2004 05:37 AM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
17, a leaking head gasket may be the culprit and is letting some cooling water in cyl at low speed/idle and at high rpm cyl press is keeping water out. Check compression (easy to do yourself) and if a cyl is low retorque head bolts to factory specs (torque and pattern) and recheck compression. A change of head gasket is the only permanent fix. If there is an accurate maintenance history, check to see if head bolts were re-torqued as required after specified hours. Good luck on your trouble shooting and happy Whalin'... Clark... Spruce Creek Navy
elaelap posted 07-07-2004 10:18 AM ET (US)     Profile for elaelap  Send Email to elaelap     
Clark and Steve,

That motor was religiously maintained and serviced. I changed the oil every 70 hours, and had the motor back in the shop three times (!) for 'tune-ups' including, on Bigshot's recommendation, making sure the head was re-torqued. Guenters should have copies of all work orders and receipts...I gave them a packet with all docs when I traded back the motor and boat.

Fairly early on in my ownership of the new motor, I posted a topic asking about the need for and frequency of 'tune-ups.' Predictably, members of this forum had differing views--some of the mechanically knowledgable said that frequent service trips to a dealership were unnecessary, while those more mechanically challenged, like myself, agreed that the expenditure of a couple of hundred dollars every hundred or hundred and fifty hours was a wise investment, especially considering the cost of a new four stroke motor. If nothing else, I concluded, service visits to the dealership would (and did) provide me with peace of mind when fishing alone fifteen miles offshore, and might well make a big difference if a warranty claim were ever to be challenged by Yamaha.

Steve--If the motor quit while I was cruising along (or worse yet fishing inshore near the rocks) with those big Pacific swells and northwesterly breezes pushing me toward shore, I'd consider it pretty 'catastrophic' and insist on at least a for it yourself up front under written protest if you have to and then submit the bill directly to the Yamaha warranty division. Don't be shy about your describing your concern (no, your FEAR) for yourself and your young kids as your engine failed and your boat drifted toward shore. It's outrageous that you're getting jacked around...this problem sounds more than a momentary glitch; I mean, I bought that new motor and maintained it well as much for peace of mind and security as for any other reason...I sure wouldn't feel secure knowing my motor might quit again at any time and in any situation!

I think you might have to push a little harder with Guenter's. You know I've posted several times, as have a few others at this site, about what good treatment Guenter's has provided, both as seller and service provider. I think you might not have expressed yourself as forcefully as you could about the seriousness of the problem with the motor.

Please keep us informed about this matter. It's of great concern to me, since I'm working on hour 80+ with my new Yamaha 115 four stroke, which I bought (traded for) only because of the good luck I'd had with your Yamaha 50 and with Guenter's dealership.


greyg8r posted 07-07-2004 01:58 PM ET (US)     Profile for greyg8r    

As a former auto mechanic, in a previous life, I always learned to check for the easy things first, and then move on to the more difficult (i.e., more expensive) fixes later.

Did, by chance, someone add oil to your gas or did you grab the wrong tank?

Just a thought...

And, by the way, did you ever send me your new pics of looloo (sp ?) 3?


17 bodega posted 07-07-2004 02:31 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Thanks all for the help.

I'll get in line at Guenters for some service.


No chance that it could be oil. It could even be steam coming from the exaust. it has done this since I got the boat. Steve at Guenters said that a little steam (white smoke) is normal and no biggie.

I also thought that since the Yammie is carbed, it doesn't run like an EFI engine at low RPMs. I will probably feel foolish that I'm even making an issue of it all. I agree with all of you when it comes to engines. Better safe than sorry.

Just made an appointment at Guenters. They are going to add a fuel/water separator to the motor. Steve thinks it is a good idea. (foggy No Cal)

Salmon Tub posted 07-08-2004 10:04 AM ET (US)     Profile for Salmon Tub  Send Email to Salmon Tub     
Steve, steam this time of year is common in my opinion. I run a 2-stroke Nissan, but I too have noticed steam in the past few weeks. It is like that every year in these weather conditons. We are out in basically similar weather conditions, fog with a light breeze, and it just has to do with the barometer and the humidity. Take the boat up to Lake Sonoma and troll around, I bet you won't see a puff of steam/smoke. Good luck
17 bodega posted 07-08-2004 11:49 AM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Salmon Tub:

Thanks for the tip. I was planning to test the 50 horse motor on some waterskis a buddy gave me.

When I talked to Steve at Guenters, he assured me that the head gasket was torqued down on a regular basis. He all but guaranteed me that it was not leaking. He also highly reccomended the yamalube gas stabilizer. come to think of it, I have never ran the gas tank below half full. could that be an issue?


17 bodega posted 07-12-2004 12:05 PM ET (US)     Profile for 17 bodega  Send Email to 17 bodega     
Thanks again for the tip, Salmon Tub.

I took your advice and, walla, not a puff of smoke. Must be a temperature or salt water phenomenon.

I'm really loving this boat and motor combo.

jimh posted 07-12-2004 08:26 PM ET (US)     Profile for jimh  Send Email to jimh     
Glad to hear it was not the engine. I was afraid it was going to be the first Yamaha engine ever reported to have a failure in service. :-)
Salmon Tub posted 07-13-2004 09:24 PM ET (US)     Profile for Salmon Tub  Send Email to Salmon Tub     
I was out on Sunday, have been trolling around alot lately, and needed to blow out the carbs, so I ran around Sausalito for 10 minutes or so at 4000-5000 rpm. It was sunny and little wind, but you could see the fog starting to come in torwards San Francisco. Had no "steam" during warm up and after the fast runs. Headed out the gate to do a little fishing and stopped a few miles up the coast. It was a relatively high but fast moving fog line, and had the "steam" coming out of the upper exhaust port while trolling. Run up to Duxbury, and out of the fog up against the beach, and started to troll. Not a puff of steam. Ran in with 2 other 17' whalers, was kind of neat. Both were pre-smirk classics. One had a single driver and the other had 4 guys in it. After watching both hulls go through the slop between Pt. Bonita and the bridge, I can say only one thing - Sand Bags. I am going to get 10 or so with about 50lbs. of sand each for my hull, and pull 4 out whenever I have a passenger. You should have seen how well the hull with the 4 guys took the chop compared to the less loaded hull. We all kept the same speed, and it would be like the difference between the ride in a Cadillac and the ride in a little 4x4 Toyota pick-up. All I need to do is figure out where to put them. Back in Sausalito, the steam was gone again. Maybe get a humidity gauge to confirm the phenominon.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.