Hard to start 2007 25 hp yamaha after sitting 2 weeks

Hi everyone i have a 2007 25 hp yamaha outboard that is realy hard to start after sitting a couple weeks..If it only sits a week it starts right up but after 2 weeks i can prime the ball and choke the liveing sh_t out of it and it wont fire unless i squirt a little fuel into the carbs or plug holes first ?Any help would be appreciated..Also one of those little black low speed idle mixture knobs is broke off on the botton carb does this matter as it idles real nice foe at least a half hour befour it starts to foul..Thanks a bunch from Dakota4x4Ps the ball on the hose gets good and hard so i dont think its the tank or hose ?

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

Check your fuel lines from tank to motor,clean the fuel filter, check diaphrams in the fuel pump, good cleaning and thorough inspection of the carbs, replace your broken mixture screw, re-syncronize the carby's and tune the mixture screws, compression test,new plugs etc etc......in other words a FULL service

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

Thanks scottcmb for the info,this motor is like new only used a few months last year so carbs shouldnt need rebuilding yet ? I have cheaked the hose and ball,the fuel filter was clean as a whistle and the motor was winterized by the dealer..Its going back to the dealer as i still have till sept 1st 2008 dealer extended warranty on it..Hopefully they will fix the broken mixture screw as its a pre set one with only minute adjustment on it anyways. so idle mixture must be preset at factory as you can only adjust the idle mixture screws about a 1/16th of a turn?Put new plugs in when i bought it as well so i guess only thing left is the fuel pump diafram or maybe something in the choke ? thanks again from Dakota4x4

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

what im curious about is HOW did the mixture screw get broken in the first place??......and another little tip.....a new or near new motor is only as good and clean as the fuel that goes into it!!!.......in other words the motor can only be as clean and water free as what is in your fuel tank and the quality of the fuel.......has your fuel been sitting around in the tank since the last time you used it before you "Winterised" the motor???........are you using E-10??

You say that you got your dealer to winterise the motor......did you ask, or did he state what the procedure is to de-winterise the motor for re-use?

im just stating and asking all this stuff in the hope it might jog your memory on something that might have been easily overlooked.......are the choke butterflies closing when you operate it??(linkage accidently dissconnected)

is it a warranty job??(unlikely but possible)

hope this helps

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

Hi Scottcmb and thanks for staying in touch..The mixture screw is a pre set from factory with the largest part inside of the carb..The piece on top of carb is a very small diameter brass about half the thickness of a pensil lead with a plastic knob on it to fine tune the adjustment about a 32nd either way..I pushed on it when the motor was on lake in boat running to see if i could get her to idle slower without stalling and it broke off and i didnt put much pressure on it..Had the boat out today and slammed the walleys and she trolled slower than my 9.9 for about 30 minutes befour i needed to open her up to clean the plugs.The only thing i havent looked at yet is the choke butterflys to see if they are closeing all the way..The motor goes in monday to be cheaked under warranty..Oh the guy at yamaha dealer said to use premium fuel from shell as it dont have any alcohol in it ..Thanks again..

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

to start with your diddling with the wrong screw for idle speed.
idle speed is set after the linkage and the air/fuel screws are set and the idle speed is set at what the manufactuer says, if the trolling speed is now to fast, tow a sea anchor.
biggest cause of carb rebuild is simply lack of use.
find a real dealer,please, do everyone a favor.
read your owners manual about fuel reccomendations.
you will most likly have to chose between Yamaha's words in the manual or the dealerships reccomendation.
trust me the manual is way more correct on fuel type. almost all modern 2 and 4 stroke yamahas are designed for regular unleaded and power will decrease if higher octane fuels are used.
your describing a choke shutter that fails to close completly, if the is a non oil injected motor run a 50/1 fuel mix. thats one of the few areas me and yamaha dissagree in writing but my services reps all agree with me.
and those plastic knobs are EPA mandated fuel mixture limiter screws.
breakage isnt a warrenty item.
a model number may help as we have no clue WHICH 25 HP motor we are disscusing.

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

Hi Rodbolt and thanks for your reply and info..Noi dont mean the idle screw i meant the fuel jet which has the epa fuel limiter black nob on top is what i broke off on bottom carb lol? Yes it says in manual to use regular unleaded octone 87 and thats what i use but the dealer says to use premium ?The mixture is 100-1 its a non fuel injected motor i used 70-1 on my old 1988 20 hp yamaha outboard for the longest time with great success so i mix the new one at 80-1 but only use yamaha 2 stroke oil in it with the anty sticking and anti scuffing additives in it.Trolls nice and doesnt defogg the mosquitos lol or my lungs ?The model # is 25MSH serial# is 1016859 2007 yamaha 25 hp short shaft rope start..Rodbolt i will look up on google about the EPA mixture screws to see what they are exactly for and will just leave them alone till a few years down the raod when i take the carbs off to rebuild from whare and tear.wont try to screw the limiter mixtuer jet out as i have no idea whare its to be set again there is enough to grab it with a needle nose pliers though.Thanks a bunch for all your help ..Dakota4x4

Re: Hard to start 2007 25 hp yamaha after sitting 2 weeks

Go by what the manual says , not the dealer , in regards to fuel octane.After all , he is in the business of selling new motors.