Wot Rpm?

[davis7210]

I have a 1983 johnson 90hp seahorse { J90TLC} and looking for info so i can install the correct prop. it is mounted on a 1983 hydra-sport x-260 boat,just want it to be dependable. thanks for any replys.

 

[walleyehed]

Re: Wot Rpm?

For the best engine life and over-all performance, shoot for 5800 with a normal load.

 

[davis7210]

Re: Wot Rpm?

thanks , i am learning alot from this site!! You just cant jump in and go in a new boat after all! i should have a diffrent boat when i get things in order. This being new to me was wondering about a 1983 motor, what should i focus on to make it run forever? I mix gas at 50-1,previous owner said change foot lube every year. Rectifier caught on fire 2nd trip out!!! luckily caught it at dock before any damage occured. so that part is new.any other maint. items i need to do?

 

[ob]

Re: Wot Rpm?

Find out when the t/stats and waterpump were last replaced.Also make sure and keep the tilt bracket bushings,steering shaft, and swivel bushings on engine greased regularly.Never hurts to inspect,clean ,and regap/replace sparkplugs either.Their condition speaks volumes as to the general health of the cylinder combustion.

 

[davis7210]

Re: Wot Rpm?

yep,was told to do compression check so will clean or replace plugs then. how hard is waterpump to replace? may go ahead before spring and know that its all good to go.

 

[ob]

Re: Wot Rpm?

yep,was told to do compression check so will clean or replace plugs then. how hard is waterpump to replace? may go ahead before spring and know that its all good to go.

Not too difficult to do a waterpump and t/stat job with just some basic mechanical knowhow.Pretty straight forward.I'd get myself a service manual though to walk you through the steps the first couple of times.Biggest pain is the shift rod disconnect ,but even that once you're familiar with the access and location is no big woop.Great part about it is that you've got iboats right at your finger tips in addition to the manual.Lots of savvy guys to assist.

 

[F_R]

Re: Wot Rpm?

One of the most neglected items is the steering cable where it goes through the tilt tube. Ignore relubricating it and find out what a pain it can be.

 

[HighTrim]

Re: Wot Rpm?

This may help with your first water pump.

"http://www.meegsonline.com/tmd/waterpump.wmv"

The goal in prop selection is to determine what propeller style and size will maximize performance for your boat, while allowing your engine to operate in the recommended RPM range. The correct propeller will prevent the engine from over-revving, yet allow it to reach the minimum RPM where maximum horsepower is produced. For every 1" of pitch size, the effect will be approximately 200 RPM. Increasing the pitch increment by 1" will result in approximately a 200 RPM drop. It is imperative, however, that the wide open throttle RPM fall within the range specified by your engine manufacturer.

A manual should be a must as stated, it will provide you with a wealth of knowledge and will more than pay for itself over. Along with the ideas suggested, you will eventually need to rebuild the carbs to prevent yourself from hair pulling troubleshooting in the future.

You are in the right place. Good luck.

 

[Dhadley]

Re: Wot Rpm?

What caught fire? Usually if a rectifier / regulator catches fire it's a water cooled one. The 83's didn't have that. The model number you mentioned stops short of telling what year it is. The next letter after C will tell. The C means 8 so if it's an 83 the next letter will be a T.

 

[davis7210]

Re: Wot Rpm?

yep it's a j90TLCTE. The rectifier that caught fire was a round metal piece with 2 yellow wires and 1 red wire if i remember correctly.It was mounted on the side of the motor. Started smoking ALOT, when i took hood off it blazed up!!! Very lucky we were at dock, had been fishing for 3-4 hours before. Just scooped some water in hand and put fire out. Thought i had just blown up my new to me bass boat! Found part online somewhere, no more issues since.Hope it last us a long time, wife and i have enjoyed our first boat very much. Also does everyone agree 5800 RPM is the number to shoot for

 

[Dhadley]

Re: Wot Rpm?

On today's fuel, 5800 is a good number. You might get some positive response from a pad bottom boat at 6000.

That rectifier is (obviously) not water cooled one. Well, it was for a second but anyway - look at your batter connections. If you have wing nuts, get rid of them. Use self locking (nylock) nuts.

 

[davis7210]

Re: Wot Rpm?

there are wing nuts attaching the wires to the battery. Is it like a bad connection with the wing nuts that possibly caused the rectifier to burn up? If so they are history!!!!!!

 

[HighTrim]

Re: Wot Rpm?

Wing nuts are a big no no. They come loose easily, frying rectifiers. If you MUST use them, make sure they are tighened by a wrench, not hand.

 

[emdsapmgr]

Re: Wot Rpm?

These engines have a tendency to carbon up the rings on today's fuel. I'd run a can of engine tuner through the engine annually.

 

[davis7210]

Re: Wot Rpm?

Something like fuel injector cleaner or like 103 octane boost?

 

[HighTrim]

Re: Wot Rpm?

Seafoam or BRP's Carbon Guard.

 

[davis7210]

Re: Wot Rpm?

Where is a good place to get either of these items?

 

[HighTrim]

Re: Wot Rpm?

You can get the Carbon Guard at your dealer, or the Seafoam at any Auto Zone or the like.

 

[davis7210]

Re: Wot Rpm?

thanks, i will pick some up on the way home from work tomorrow.

 

[HighTrim]

Re: Wot Rpm?

Seafoam



Carbon Guard