1994 Yamaha 30 ELRS idle adjustment?

[cumminsford]

This is my first time to the forum.Hello everyone.I hope to find some help here.I recently aquired a Gregor 15' with Yamaha 30 console controls.The first time out the boat had problems shifting from idle into gear-it would die.So i checked the primer bulb,changed out the existing fuel with new,and replaced the existing spark plugs (which were one heat range lower than Manufacturers spec)so i figured that might have been it.So today i take the boat to the lake,it fires up and idles fine,i cruise it half throttle (15 mph) for about 2 miles.I stop and shut down,re-start is fine,into gear and full throttle about 5 miles or so,stop and shut down.Wait 5 minutes,motor dosent want to start,let alone idle.I raise choke lever to start (warm up) an already warm motor,and manage to get it into gear with out the motor dying (this is the main problem)and finesse us back to the dock.Im thinking the carbs need to be fattened up a turn or two,since the choke was needed to start the warm engine.Any experienced opinions here?I have gotten conflicting advice on number of adj screws,etc.This motor has 3 carbs with one adj. screw near the top of each carb,mounted on the side.I have looked on line and at local dealers for a manual but they are all out of stock.I sure could use some help.Thanks,Mark.

 

[rodbolt]

Re: 1994 Yamaha 30 ELRS idle adjustment?

try draining the carb bowls and doing a spark and compression test. but my guess is clogged carbs if no mechanical malfunctions are noted. carefully inspect the fuel pump as well. the carb mixture screws on those carbs do not meter air to fuel the actual air to fuel ratio is determined by the idle fuel jet and the pilot air jet. all the mixture needle does is allow more or less of the mixture into the crankcase whith the shutters closed. if much evidence of trash is appearent on the drain plugs odds are the carbs are stopped up. inspect the ends of the drain plugs for varnish or gunk.<br /> if ya see much odds are the main and idle jets are building up as well. the idle fuel jet gets it fuel from a passage drilled under the main fuel jet. the idle fuel jet is a tiny passage as well.

 

[cumminsford]

Re: 1994 Yamaha 30 ELRS idle adjustment?

Update:I pulled the drain screws off of the top two carbs and looked at them under magnification,they were very clean.I checked compression and they were both at 90#,i performed a visual spark check with plugs in boot,positive spark.So while i was scratching my head i decided to check the bottom carb drain plug,as its a little more difficult to get at.The darn thing was finger tight or should i say loose? I am going to put the hose to it as it sits and see if its losing fuel there as I assume it was/is.Maybe the outboard gods smiled on me this morning.....