Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Johnson 90 difficult starting after warm

Posted by MichaelVT on 09/11/12 - 6:19 PM
#1

I'm hoping someone has had the same problem I'm having.
I have an 1989 90HP Johnson with VRO. The VRO pump was replaced by the dealer as well as the pulse limiter, the carbs were rebuilt this winter, I have a new gas tank with fresh fuel and new plugs.
It starts great after I put it in the water with a push of the choke. I take the kids tubing, anchor and then when I go to leave, I turn the key and it cranks but doesn't start or starts and then stalls. I have to pull out the throttle and give it gas and it starts and smokes a bunch. It calms down after a few minutes, doesn't smoke anymore and runs fine. I thought the pulse limiter was letting oil back flow into the cylinders because when I removed the plugs they were wet with oil. I checked it and it's a blue limiter not the black one that is the older one.
My thought is that it should start up after being warm with just a turn of the key but it doesn't.
Does anyone have any ideas of what to look at/replace??
Thanks for your time.

Edited by Joe Kriz on 09/11/12 - 7:00 PM

Posted by Joe Kriz on 09/11/12 - 7:01 PM
#2

Edited the abbreviated year to the full 4 digit year of 1989.

Please see this post.
http://www.whalercentral.com/forum/vi...d_id=15197

Posted by thegage on 09/11/12 - 10:00 PM
#3

I have a 1992 Johnson 90 VRO. When starting it warm I pump the primer bulb until it is firm, advance the throttle slightly in neutral, and then it fires right up, smoking more than usual. After a few moments it settles down. If I just turn the key without doing the above the engine starts but stalls. As far as my experience goes there is nothing wrong with your engine, it is typical of many 2-stroke motors and nothing to worry about, but others may think different.

John K.

Posted by CES on 09/12/12 - 6:02 AM
#4

Gage...I do the same thing with my 40hp.....always make sure the primer ball is hard.....even while starting a warm engine.

Posted by Tom W Clark on 09/12/12 - 7:33 AM
#5

You should never gave to squeeze the primer bulb to start a warm motor. If you do need to, it indicates something is wrong.

If the motor is hard to start, this indicates a lack of fuel being supplied to it. There are numerous reasons why this might happen but two simple causes I can think of are:

- Old fuel pump growing weak. It costs about $30 for a fuel pump rebuild kit. It might be good preventative maintenance at any rate.

- Clogged cooling system causing excessive powerhead temperature. If the powerhead is hotter than normal at shutdown, the gas in the carburetors can be evaporated away making it very hard to restart.

Posted by thegage on 09/12/12 - 9:10 AM
#6

Actually Tom, now that I think about it I just replaced my aftermarket primer bulb with a new OMC one (I suspected the old one was allowing fuel to leak out) and haven't hot started the motor since doing that. It will be interesting to see how it goes when I'm out on the water this weekend.

I don't think the OP needs a fuel pump as he just replaced the VRO.

John K.

Posted by MichaelVT on 09/12/12 - 9:21 AM
#7

Thanks John K and Tom.
I will check the gas line bulb next time I'm out but still think it's something else because each time I start it cold with just the choke it starts right up with no smoke. It's when it's warm, is the problem. I would expect it to be difficult to start cold, not warm!
Anyone else have any ideas?
Thanks.

Posted by kamie on 09/12/12 - 11:01 AM
#8

Where is your battery located?

I ask because my neighbor has a new 125HP Optimax that would start when cold but would not start once he had run for awhile. The solution was the battery was too small and the wire run from the engine to the battery was the wrong gauge. Once those two things were resolved, his issue went away?

Posted by MichaelVT on 09/12/12 - 5:24 PM
#9

Thanks kamie,
My battery is on the starboard aft side of the boat...

Posted by MichaelVT on 09/13/12 - 6:31 AM
#10

Does anyone feel that, the primer bulb on the oil tank being hard as a rock from age, has anything to do with it?
I think I might replace it to see if it helps. Is that the same part as for the gas line or specific to the oil line.
Thanks.

Posted by Derwd24 on 09/13/12 - 7:16 AM
#11

Doubtful that's the cause of your problem. If you prime it when warm starting w/o advancing the throttle, does that help?

Posted by Bake on 09/13/12 - 9:30 PM
#12

Did you run this motor for years prior to the work? Is this a new problem to the motor, or has it been that way since you owned it? It is pretty common for a outboard to smoke more when you crank it then kinda go away. This is the residual oil pooling in the cylinder. I had a 88 JOHNSON and hated it for the same “would not start when warm problem”. Two stroke outboards have a mind of their own so to speak. Everyone will tell you that you should never have to choke a warm engine. You will often here you should not have to give it high idle when warm. Well guess what sometimes you just got to figure out what combination works for your motor. I have found on the Johnson as well as a 175 Merc that I owned that both of the motors liked to be choked on every start, warm or cold. Hold your choke in just when it fires off release the choke. If that does not work every time try a little fast idle with the choke from the start method. I bet she fires off much more reliably.

Posted by MichaelVT on 09/14/12 - 7:15 AM
#13

Thanks Dave, no, I don't prime the bulb before starting it. Maybe I'll try that to see how it works.

Bake, I purchased it last year. The boat wasn't maintained by the previous owner and ran like hell. That's why I redid the carbs, gas tank, fuel line, plugs and the dealer replaced the VRO pump because it the warning beeper was beeping intermittently. Maybe it's just a two stroke thing? I had a 1971 75ph Johnson growing up and it started without a problem warm, with just a twist of the key...

Posted by Bake on 09/17/12 - 4:29 AM
#14

I do not know why it seems those 3 cylinders always fire right off. When it comes to the 4 cylinders omc motors they seem more difficult to find the starting combination. try the choke even when warm I believe you will see a difference.

Posted by thegage on 09/17/12 - 12:20 PM
#15

Well, yesterday I ran the boat with a new primer bulb. With the engine warm I didn't prime the bulb or advance the throttle in neutral. The engine fired right up and idled with no problems. My "old" bulb was less than a year old. Might be worth it for the OP to source a new OMC bulb.

John K.

Posted by MichaelVT on 09/21/12 - 6:32 AM
#16

I ordered 4 new coils and wires. I'll see if that solves the problem.
I'll let you know.
If anyone needs a Pulse limiter, I have a new one that I didn't use. It's the blue one and the part number is 0435009.

Edited by MichaelVT on 09/21/12 - 6:34 AM