100hp 4cyl 2+2 outboard help!!

[jafitzwater]

Hey guys, I have a 1989 Mercury 100hp 4cyl with the 2+2 system.

The motor was on a boat I bought and it had a blown piston.

All the fuel lines and everything on the motor were pulled off and I rebuilt it. When putting the motor back together I triedl my best to guess where the lines went from the manual since the manual is extremely vague on this motor.

My problem is now that I got the motor to idle perfect, however when trying to accelerate to WOT it falls on its face... it?s like the 2 other cylinders never kick in...

I?m almost positive it?s due to improper fuel line setup, since this motor has fuel hoses all over be place like a spider web!

My question is, does anyone else have this motor that can send me some pics of how it?s supposed to be setup? I have searched the googles and again it?s very vague and gives me a ?generic? diagram that is missing things my motor has so it makes no sense.

The motor is sooooo close to being fishing ready! I?ve taken it out to the lake multiple times just to find when I WOT the boat doesn?t hardly move and I?m chugging along at 10mph lol


Please help any ideas are welcome, pics are HIGHLY preferred!

Joe

 

[flyingscott]

You must have a factory manual for that motor. Pics won't help you much because the lines run all over on that motor. First thing make sure the carbs are on the correct cylinders because the top 2 are different than the bottom ones. The accelerator pump lines got to the bottom cylinders and the primer lines are on the top 2.

 

[jafitzwater]

Thanks, i kept the carbs in the stock location and just pulled the bowls off them individually. So i know they're in the correct location. However the lines going to them.. who knows? The reason i was looking for images was to confirm the lines coming from the accelerator pump and also the enricher.. as to where it all goes, because i'm pretty sure i didn't put it in the right location...

 

[jafitzwater]

Here?s the current setup.. anything look out of place? Thx!

 

[jafitzwater]

motor is still down, unfortunately... anyone have any more ideas?? Im pulling what hair i have left out...

 

[Faztbullet]

Got a manual???? Sounds like the accelerator pump or injectors are set/plumbed correctly

 

[jafitzwater]

@Fazbullet yes i have the manual, however its quite vague due to the models of each variation of this motor being quite similar, but different... if that makes sense... there's no CLEAR answer.

 

[gbrowne9]

i just checked my 1989 115 and the lines look the same.after i rebuilt my engine i put one of the fuel pump gaskets in wrong and the motor would not accelerate.check if #3 plug is soaked .if so fuel is being pumped directly into #3 clyinder from the pump.also check if eccelerator pump is working.

 

[wn6ngp]

i just checked my 1989 115 and the lines look the same.after i rebuilt my engine i put one of the fuel pump gaskets in wrong and the motor would not accelerate.check if #3 plug is soaked .if so fuel is being pumped directly into #3 clyinder from the pump.also check if eccelerator pump is working.

this is a good point. I did the same thing on 90hp 3cyl. I rebuilt the fuel pump and was careless about the order of the gaskets. It started on the earmuffs but not in the lake. Similar problem with the ref manual as it showed multiple designs of similar fuel pumps with different orders of gaskets. Finally figured it out. The trick to figuring it out was to correlate the exact hole locations of the gaskets with drawings in the manual to decide which fuel pump was mine.

 

[Faztbullet]

If that's blue RTV on crankcase halfs motor needs to come apart.....

 

[racerone]

I saw the blue stuff too.-----I only use " gel seal " or loctite 518 on assembly.---------Folks do not like negative comments , but I agree blue RTV would be the wrong stuff !!