1999 90 HP Johnson Help!

[17SeaEra]

I'm hoping someone out there can help with my 1999 90 HP Johnson. I purchased the boat and motor new in 1999 and have never had any problems with the package. Unfortunately, at 177 hrs. I decided to complete some maintenance items. I had a local repair shop replace the water pump and thermostats. I thought I could handle the decarbonization. This is when my trouble started. I followed the directions on the can and even had the repair shop give me directions before I started. There is a red knob under the plastic breather with a male end on it for the decarbonization can fitting. I emptied the can per the shop directions into the fitting infront of the red knob. The motor smoked like there was not tomorrow but ran fine afterwards. I guess I moved the red knob from its original setting and I have no idea where it should be set. The worse part is I cannot start my motor now. I have taken the brand new plugs (gapped correctly) out wiped them clean but I all the motor does is turn over. It tries to start by coughing as it turns over but it will not start. Any help would be greatly appreciated!

Walter

 

[tashasdaddy]

Re: 1999 90 HP Johnson Help!

it turns back in line with the body of the solenoid, is normal operation, activated by the key.

 

[bobothewizard]

Re: 1999 90 HP Johnson Help!

Hmm, i never knew we could just get a can of decarb and stick it on that schrader valve on top... Would this be the same idea behind the decarbing with some sea foam directly down into the cylander from the spark plug hole?

 

[17SeaEra]

Re: 1999 90 HP Johnson Help!

Yes. The can has a tube or hose that screws on to the shrader valve with the red knob.

 

[bobothewizard]

Re: 1999 90 HP Johnson Help!

can you tell me the name of the stuff you are using please.

 

[17SeaEra]

Re: 1999 90 HP Johnson Help!

Thanks tashasdaddy! I have the red knob in that position. I guess that means I must have another problem. I wonder if I have indirectly clogged something up in the carb during the decarbonization. Really strange that it will not start now.

 

[17SeaEra]

Re: 1999 90 HP Johnson Help!

I think the product is called Valvtect Motor Decarb

 

[Cricket Too]

Re: 1999 90 HP Johnson Help!

17Sea....the decarb you ran through the motor does not go into the carb, that shraeder valve on the primer bypases the carb and shoots directly down the intake. Make sure that the red valve is not in the manual position(perpendicular to the valve body) and make sure it isn't cracked and leaking. If it won't start in the direction it's in, try moving it to the other direction.

How exactly did you decarb, usually your not supposed to use the whole can in one shot, and most engines won't burn through that much decarb. Once you let it sit in there overnight, it needs to be blown out, preferably under load, running in the water at WOT.

Decarbing can clog up recirc valves, but that shouldn't keep you from starting. Seeing as how you used a whole can I am betting that there is too much left over in there. I would pull the plugs and crank it over a bunch of times(with the water running) and try to blow some of it out of the cylinders, make sure the plugs are grounded when you do this.

Bobo, you can find cans of decarb at any marine store under all different names, but to answer your question, no it's not the same as spraying down the spark plug hole, this actually runs it throughout the engine and cleans carbon from the rings and exhaust ports. It can also be done by just spraying decarb down the carb throat while running, on engines without a primer solenoid.

 

[17SeaEra]

Re: 1999 90 HP Johnson Help!

Lieutenant:
Thanks for the input. According to the directions on the can, I was supposed to use the entire can during the decarb process. The local shop also told me to use the whole can. My brother-in-law actually used two cans with no trouble. The motor bogged down but pushed through the decarb process. It actually started fined the next day and I ran it for a quite some time. However, today was a different story. This is the first time it would not start at all. I took the spark plugs out and turned the motor over numerous times, about 30 seconds or so. I cleaned the plugs up and re-installed them but still the same old story. The motor turns over coughs like it wants to start but will not. If I cannot figure this out by Sunday evening, I guess I will have to pulled it to the repair shop on Monday morning. Again, thanks for the help!

 

[17SeaEra]

Re: 1999 90 HP Johnson Help!

I cleaned the fuel filter today but I still cannot get the motor started but I do have spark and the end of the spark plugs are wet. Therefore, I would assume they are getting fuel. Can someone please tell me how do you know if the cylinders are getting sufficient fue to fire? I'm thinking another item might be clogged or the fuel pump might be failing. Thanks again!