90 HP Mercury Starting Problems

[1986 Cheetah]

I recently purchased a 1986 Cheetah F/S with a 90 HP Mercury in line 6 and power tilt/trim. I am not sure of the year of the motor, but I will get the serial number and post it later.

The seller started it right up for me and it ran and sounded great. We took it to the lake and had no luck with starting up. We then took it to a mechanic that said it started fine for him as well. He also told me that these models were notoriously hard to start, but once warmed up were excellent motors.

The mechanic gave me instructions on how to start it and we finally got it running yesterday, but I cannot start it as consistenly as I would like.

Is there anything I can do to get it to start easier?? Other than just learning to get a feel for it obviously.

Thanks

 

[Floater49]

Re: 90 HP Mercury Starting Problems

I am certainly no expert on these motors. Let me state that for the record. However, I am learning my 115 inline quickly with the help of others on this site.
I strongly suggest that you do a link and sync (search for it by Clams on this site) on that motor. I did it on mine, and although I had some confusion with terminology, I now need only to breath on the key when warm and it fires instantly.
Before you start it cold, pump the bulb till hard then squeeze it hard for another 5 seconds. lift the warm up lever, hit the choke, and crank it over. Mine takes about 5 seconds and it fires right up.

 

[1986 Cheetah]

Re: 90 HP Mercury Starting Problems

Thanks, I think I was being a bit timid with the bulb. Are there no worries about over squeezing?

After it started and ran fine for a while, we cut it off for a little while. After that, I had to pump the bulb again before restarting. Is this something that should concern me?

Thanks again, for helping this rookie out.

 

[Floater49]

Re: 90 HP Mercury Starting Problems

From one rookie to another, I have to re squeeze after I have the engine shut off even for 5 minutes. And if there is a danger of over sqeezing, I guess I'll find out too!

 

[target62]

Re: 90 HP Mercury Starting Problems

I'll throw in another rookies experince, I have a 1988 90 hp 3 cyl and it did the same thing, and I rebuilt the fuel pump and replaced the fuel lines all the way to the fuel tan and that solved all the prolbems, it now starts with the first turn of the key cold or warm

 

[1986 Cheetah]

Re: 90 HP Mercury Starting Problems

Thx a lot guys, I gave it a try last night with more squeezing and it started right up. Hopefully I will get this result every time!!

 

[mattmjm90]

Re: 90 HP Mercury Starting Problems

I have a 1985 90hp inline 6cyl on a 1978 19' Sea Ox cc. The original owner started it fine but warned me of flooding from priming too much, not sure if my engine has a problem or that is common. I have a hard time starting it myself. Once she gets running for awhile shes fine. I wouldn't mind getting some help on the subject myself.

 

[electricjohn]

Re: 90 HP Mercury Starting Problems

If you have power trim, be sure motor is level (plumb) before cranking.

 

[78 GT-150]

Re: 90 HP Mercury Starting Problems

Thanks, I think I was being a bit timid with the bulb. Are there no worries about over squeezing?

After it started and ran fine for a while, we cut it off for a little while. After that, I had to pump the bulb again before restarting. Is this something that should concern me?

Thanks again, for helping this rookie out.

I have the same problem with the same motor... Can you "overprime" the bulb?

I am also a newb. (I just bought it yesterday)

 

[78 GT-150]

Re: 90 HP Mercury Starting Problems

I am certainly no expert on these motors. Let me state that for the record. However, I am learning my 115 inline quickly with the help of others on this site.
I strongly suggest that you do a link and sync (search for it by Clams on this site) on that motor. I did it on mine, and although I had some confusion with terminology, I now need only to breath on the key when warm and it fires instantly.
Before you start it cold, pump the bulb till hard then squeeze it hard for another 5 seconds. lift the warm up lever, hit the choke, and crank it over. Mine takes about 5 seconds and it fires right up.

Where is the "Warm up lever"?

 

[electricjohn]

Re: 90 HP Mercury Starting Problems

If you over-enrich the motor during cranking, it will be hard to start. You have to find that sweet spot.

 

[BoobieBouncer]

Re: 90 HP Mercury Starting Problems

I had to pump the bulb again before restarting. Is this something that should concern me?

I have to re squeeze after I have the engine shut off even for 5 minutes.

I rebuilt the fuel pump and replaced the fuel lines all the way to the fuel tan and that solved all the prolbems, it now starts with the first turn of the key cold or warm

target62's advice is good. You could have a hole in your fuel system somewhere and could be sucking air. The problem could be in the fuel pump, the primer bulb, or the fuel lines...

The original owner started it fine but warned me of flooding from priming too much

Are there no worries about over squeezing?

Can you "overprime" the bulb?

If you squeeze the primer bulb hard enough you can force fuel by the carburetor needle and seat and dump fuel into the engine which will flood it.

I have a hard time starting it myself. Once she gets running for awhile shes fine.

Having your fuel idle mix lean is a cause for hard starting. You could try turning your carburetor idle mix screws out a little.

Where is the "Warm up lever"?

Here is a picture of my warm up lever in the down and up position.

 

[78 GT-150]

Re: 90 HP Mercury Starting Problems

Here is a picture of my warm up lever in the down and up position.

I don't have one of those... I wonder why?

 

[higgy3209]

Re: 90 HP Mercury Starting Problems

I am new at boating and i have i 84 mec. and i was told of a way to start this thing everytime. make sure the bulb is pumped up and pump it one more hard time. *note there is an arrow on the bulb make sure it is pointing upward.also like someone said before make sure motor is level. i think that is the key. i then hit the choke twice and hold the choke in and turn over. if it doesnt start right away i push the trottle up just a lil and turn it over. man now that i have found this all out i enjoy my weekend on the lake alot more. hope you figure yours out.

 

[paratpr]

Re: 90 HP Mercury Starting Problems

I have a 90 h.p. merc. and found starting when cold takes a while.I squeezed the bulb,put the throttle lever forward,and pushed the key in (choke?)and it started.however,the last couple times out,after it started ,a pretty big cloud of white smoke would appear.whats with the smoke?

 

[Bill kubiak]

You really cannot over pump the bulb unless the needle valves in the carb are not seating or the float is incorrectly set. Once the full bowls are full the floats shut off the fuel no matter how hard you pump, once the motor is running the pressure in the fuel line then becomes a suction.
Also that primer you push in only does something if the engine is actually cranking or running it redirects some of the fuel pump pressurized fuel to a port at the rear of the carbs directly into the crankcase to prime.

 

[JP-07]

I have a 90 hp Mercury and having a difficulty getting start. I'm afraid of over pump n flood the engine. Should I continue squeezing the bulb n keep trying? Please help.

 

[GA_Boater]

Look here - http://forums.iboats.com/forum/engi...iner-outboards/10012361-hard-starting-merc-90