115 V4 Yammy - runs well then dies at idle

[scottoz]

1992 V4 yammy - running beautifully yesterday to fishing spot. Started well and came back at between 4,000 - 5,500 rpm great for 35 mins. Pulled it back to idle at marina from 5000 rpm and it started to die. Sounded like it was choking - opened throttle gently but even at full throttle it did not increase revs at all. Put in in Neutral and used fast idle lever and it reved up. Then it died when I went to put it in gear. Tried to re-start and would only re-start with choke (this is sunny Queensland in 35 degree celcius heat and hot motor!). Only just got it into Marina with it choking and it died as I touched the jetty. Took it home and flushed motor and it started great and ran (without load) well. At not time was there a lean sneeze or backfiring heard. What gives? Any thoughts. I wondered whether it needs a carb clean.<br /><br />Thanks for your help

 

[rodbolt]

Re: 115 V4 Yammy - runs well then dies at idle

hello<br /> yes it sounds as if the carbs have no fuel in them or maybe have water in them. try draining the bowls and inspecting the filter. you may open them carbys up yet. good luck and keep posting

 

[scottoz]

Re: 115 V4 Yammy - runs well then dies at idle

thanks rodbolt - I will check the fuel lines for any areas that could allow air in and will check the seperator for water and post the results.

 

[scottoz]

Re: 115 V4 Yammy - runs well then dies at idle

I had a look at the Engine filter - the small white and black job. It is just a filter, not a trap and it was free of debris. I then drained the water trap in the boat, into a cup. I used to have a boat with a plastic tank and water in the fuel never seemed to be a drama. In this boat however I have twin steel tanks (alloy actually). The cupfull that I drained out smelled only fainly of fuel. It looked and smelled like water with a hint of gas. This seems to have been my problem. <br /><br />Sounds funny - but how do you tell. What was in the bowl looked a little clearer than fuel should - is that the give away? Would you normally drop some out of the bowl after each outing if the boat has had fuel sitting a bit to be sure?<br /><br />Cheers

 

[rodbolt]

Re: 115 V4 Yammy - runs well then dies at idle

hello<br /> sounds like you may have a fuel fill leaking. but the filter on the engine should be mounted on a bracket on the port bank. should be just about where the blck meets the crankcase. should be a screw on little trap.<br /> but yes now that you are getting water in the filters I wouldtecomend you check it every 5 hours until the problem subsides but it would be better to pump the tanks dry.water in gasoline forms an acid that will eat at the tank bottom. so you can drain it now or it may self drain later.flush the carbs cause once water is in them you cannot get it out other than flusing by removing the bowl drain screws and pumping gas through them. dissconnect the battery first and put out all smokes and do it outside with a water hose to wash away the fuel.<br /> good luck and keep posting

 

[Capt. Stabbin]

Re: 115 V4 Yammy - runs well then dies at idle

Is your primer ball staying hard? My 88 115 was doing most of the things that yours is doing. After replacing all lines, primer ball, $$$ carb rebuild, it turned out to be 2 holes in my gas tank. Good luck.

 

[spete]

Re: 115 V4 Yammy - runs well then dies at idle

RB - you're saying that no mater how much fuel you run through the carb that you'll never get the water out of the carb bowls?

 

[scottoz]

Re: 115 V4 Yammy - runs well then dies at idle

Hi Rodbolt and Co - thanks for the answers. I suspect that my real problem may have been air getting in the fuel line because the bulb was not that hard. With the motor off last night and all the kids in bed (quiet!) I squeezed the bulb and I could hear some air escaping. I took to the hose clamps around the bulb and engine and they tightened up some and hey presto, no more air leak noises. The water issue however concerned me. RB - I like your humour about self draining tanks - I will drain them.<br /><br />As for the fuel bowls I dont have a manual. If its an easy job (I have some experience with Carbies on cars), could you please let me know what the screws look like and where located and I will do the job.<br /><br />Thanks for your help guys - much appreciated.<br /><br />PS. I love this motor. I had an old 1975 Haines Hunter that I re-powered with a 2000 Merc 60 3cyl 2 stroke, but I have to say as nice as that motor is the Yammy is quieter and smoother - probably largely to do with it being a V4 I suppose.

 

[scottoz]

Re: 115 V4 Yammy - runs well then dies at idle

Sorry to hassle you RB - you are in demand on this site. <br /><br />Cheers mate.

 

[rodbolt]

Re: 115 V4 Yammy - runs well then dies at idle

hello<br /> no hassles mate<br /> I just like sharing my knowledge. the reason for thye self draing comment is just yesterday I finnisd installing a 180 gollan tank in a 25 hydrasports with a pair of 225 jonnyrudes. water sitting at the bottom caused the aluminium to corrode and it drained 60 gallons of gas all by itself.<br /> good luck and keep posting

 

[rodbolt]

Re: 115 V4 Yammy - runs well then dies at idle

hello<br /> wow. to answer spete question<br /> no <br /> run as much gas as you wish and all you mnay accomplish is to burn a piston due to a lean fuel condition. that is why I dont use treatments like gas dry. by the time it dries the gas its eaten up the pump and burned a piston. drain and flush and all is welkl. good luck and keep posting