Johnson high RPM

[redfish1940]

I took a boat out for the first time and ran it. Its a 21' hrydro sport. with a 2000 J200VSIF Johnson 200hp. Anybody know what the red line is on the RPMs If the gage is right it shows 7,500 at abot 35 miles a hour.
I think its a factory prop.
It motor smokes alot also but I am working on that. the compression is between 85 and 90 on all cylinders
thanks

 

[BaileysBoat]

Re: Johnson high RPM

According to this 6000 rpm.

http://www.piranha.com/motor_specs.php?id=4618

 

[billy4hp]

Re: Johnson high RPM

Tach is most likely installed wrong...

See if you can get a brand name off the tach and search the web for installation instructions...

Different tach / engine combinations take a different "pole" setting, which is basically a fancy way of saying that the tach is getting the correct signal to read RPM's correctly...

HTH...

 

[ezeke]

Re: Johnson high RPM

The built-in rev limit on the stock powerpack for your engine is 6,700 RPM

The gauge should have a dial on the back and it should be turned to 6P.

BTW, the model number J200VSIF is from model year 2001.

You will need to know the pitch of the propeller to make sense of any calculations. Take the propeller off and see if there are any numbers stamped anywhere.

 

[redfish1940]

Re: Johnson high RPM

thanks Ill check

 

[redfish1940]

Re: Johnson high RPM

I got time to check the prop size today its 15 1/2 x 15. it looks like someone changed the prop when the boat was sold.

 

[billy4hp]

Re: Johnson high RPM

I got time to check the prop size today its 15 1/2 x 15. it looks like someone changed the prop when the boat was sold.

Wow that's scarey... I would imagine you should have a 21 - 26 pitch.....



No wonder it's smoking a lot.... Your tach is probably correct and it's banging the rev limiter all the time (still dumps fuel just cut's out the spark)....

 

[ezeke]

Re: Johnson high RPM

Try your 15 pitch and 1.86 gear ratio on the calculator. At 35 MPH your theoretical RPM should be 4,583.

http://go-fast.com/Prop_Slip_Calculator.htm

You want to be at maximum 5800 to 6000 at WOT with an average load.

Be careful about pitch - too much and you will lug the engine and drastically reduce the engine life.

 

[billy4hp]

Re: Johnson high RPM

Try your 15 pitch and 1.86 gear ratio on the calculator. At 35 MPH your theoretical RPM should be 4,583.

http://go-fast.com/Prop_Slip_Calculator.htm

You want to be at maximum 5800 to 6000 at WOT with an average load.

Be careful about off the cuff advice about pitch - too much and you will lug the engine and drastically reduce the engine life.

Ezeke,

Wasn't trying to be off the cuff about pitch... I just can't imagine a 200hp outboard running a 15 pitch prop unless it was pushing 10,000 lbs...

Trust me, I am no prop expert nor do I claim to be...

If the correct prop was in doubt, I would go start another thread in the prop forum.. They helped me out a lot...

JMHO...

Billy

 

[redfish1940]

Re: Johnson high RPM

thanks I just took it out to water test it because everbody tells me it it allways smokes more on the muffs.but it still smoked bad in the water. I didn't run a high rpm I knew somthing was wrong .I only opened it up for a few seconds.
will it smoke if the fuel side of the vro pump is bad?. there is kits for that but not the oil side. I would think the oil side is ok because its getting to much oil. but I don't know to much but I am enjoying trying to learn.
I be 71 next month and trying trying to stay out of my wifes hair .with challanges
Thanks again Everbody . Ill try the prop forum

 

[ezeke]

Re: Johnson high RPM

Edit

 

[redfish1940]

Re: Johnson high RPM

thanks I seen the vido befor . I checked for leaks and changed clamps the primer balb stays hard and makes no difference when I squeese it while the motor is running
I am now going to take the vro apart I guess and clean it. maybe something is stuck.