1988 120 Johnson Slow Quick Start

einer

Cadet
Joined
Aug 28, 2005
Messages
13
Mr. J Reeves and Mr. Dhadley helped me a few years back, with timing and sync-link issues, thank you to 2 very knowledgeable men who enjoy there trade. My question is upon a cold start it seems to take forever (5 minutes not uncommon) running at fast idle until the rpms settle down so I can put the motor in gear. Thermostat replacement needed or??? Granted the boat is still in storage as here in Minnesota there still driving cars and not boats yet on the lake. Thanks
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1988 120 Johnson Slow Quick Start

when was the last time the carbs were cleaned, and rebuild kits used? Have you changed your fuel lines to alcohol resistant lines?
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: 1988 120 Johnson Slow Quick Start

QuikStart advances the timing until the temp switch informs the powerpack that the engine water has reached >96? F. or, until the RPM reaches 1100, whichever occurs first.

If QuikStart is working properly, you can disable it by raising your warm-up lever enough to reach 1100 RPM, then lower it to normal.

Or, you can assure yourself that the temp switch with the black and white wire is connected and that the switch is working properly and that the engine temperature is reaching at least 96? on that bank of cylinders....

Early !988 120 and 140 models sometimes had a problem with the spark advance rod and adjustment stop not allowing the throttle plates to close completely. This resulted in a fast erratic idle. If you find that this condition exists on your engine, ask your dealer for Service Bulletin # 2201 and see if he can replace the adjustment stop if needed. Link and sync has to be redone after this service, so if you don't have the factory service manual and a copy of the service bulletin, it would be advisable to have your service department do the work.
 

einer

Cadet
Joined
Aug 28, 2005
Messages
13
Re: 1988 120 Johnson Slow Quick Start

Carb kits including floats and lines were done last year. This gives me some direction to go as to temp and rpm. Raising lever during warmup above 1100rpm does not affect the fast idle. Ill recheck the sync and link adjustments and try to determin if the temp sensor is any good on the back of the heads.
 
Top