1st boat, 1st day trouble.... help !

[Stew]

Like I said, 1st boat, 89 yamaha 115, ill try to explain as best I can....

Hard to start needs choke and neautral lever all the time to start.

will run just fine 1000 to 2000 rpm, at 1st it would run 3500 and up no problem, 3 minutes into run it started "bogging" down and woul not go above 1800 rpm, no indicator lights and both oil tanks at right levels.

shut itself down... restarted... it willl do any rpm with the neutral lever but in gear 1800 rpm.

I started bumbing the choke on the remote and noticed it would speed up for a 2nd .... so i kept bumping it and walla up to 4000 rpm and ran just fine there (well seemed a little boggish) but could run up there all I wanted, if i slowed to 2200 rpm or slower same thing, wouldnt go back up and idle speed it would die..... tried the choke switch bumping and after a while it would take off.... ran for 20 minutes sorta ok, just seemed a little boggy........

again slow down to 2000 rpm and wouldnt go back up, kept dieing at slow speeds and deiing at idle.. but in meutral i could rev to my hearts content and in reverse could rev all i wanted, in fwd gear it would sputter and die (killer on a new guy trying to line up with a trailer and cough sputter dead.... ruh oh....)

any help would be appreciated.... worked on helicopters for many a year in my past but never an outboard, if something i can do myself would love to give it a shot......
Thanks

oh ya, i did put new plugs in and cleaned the fuel filter after this happened and it did the same thing.... 2nd try it seemed to burn off the fuel FAST.....

[jb123]

if choking helps, clean your carbs.

[Stew]

I guess saying choke makes it run faster wasnt entirley correct, its more of "feathering" it, bump it let go bump it up let go, eventually i get up on plane then she goes.... I guess im confused cause in neutral i can rev it as fast as i want....

is there a procudre for cleaning these, easy job or tech. type job ?

[Hamfisted]

Yep, the carbs are clogged. Specifically the idle jets. In the old Yamaha carbed motors the idle jets sit horizontal in the bilge of the carb bowl, and as the fuel evaporates it leave gum and varnish behind. This stuff settles right into the idle jet passage and the idle jets themselves. The idle jets are those small brass screws on the bottom sides of each carb bowl. They're on the outboard sides so you can remove them with a screwdriver and clean them out. After '97 they moved the idle jets vertically in the carb bowls to try and eliminate some of this problem but it still occurs albeit less often. Take the air cover off so you can get to the idle jets easier. Remove them and clean them and the bowl passage out real good with some Amsoil Powerfoam or Berryman's Chemtool spray (Walmart). There are two tiny orifices in each jet, make sure these are clear. A piece of stainless leader wire works well for poking through there. The larger brass screw is the main jet. If you want to you can remove these too, but inspect the rubber O-ring on the ends if you do. If they're old they will crack apart when you pull the jets out and they're $5 each at the dealer. The idle jets just have an aluminum washer on them. You might find that these have deteriorated too and need to be replaced. All this stuff is available at the dealer, not the hardware store. In the future use some gas stabilizer in the fuel tank (Sta-Bil .... Walmart) and run the motor every couple of weeks. If you don't, get use to doing this carb cleaning routine a lot.

Good luck.


-Mike

[ April 22, 2007, 12:38 AM: Message edited by: Hamfisted ]

[Stew]

Wow, thanks Mike Muchly appreciated...

LOL used to have a pilot that would say... "here hold my coffee and watch this sh@t"...... you knew you were in for trouble when he said that.

[Stew]

Awesome, tore down the carbs this morning, cleaned and reinstalled, spent4 hours with the kids flying around the lake with no trouble at speed, its very hard starting (choke at remote seems ineffective, have to choke it back at motor) so i probaly borked the auto choke somehow......

idleing around at 800 or below cuase a die.... anything above and its fine...