1983 35 hp johnson slips and revs real high

[Grassman619]

It's had over heating problems and wouldent spit water out the taltail itwas fixed and the main wire harnest relpaced first test run went great ran strong the next test run after 2 minutes in full throttle it just reved up and slowed down I backed the throttle down and at slow speed it ran ok ounce I gave it more throttle it would slipp like a car with a bad tranny it wouldent kick out of gear just rev up high and go nowhere I changed the gear oil befor the first trip and checked it after each trip it's full and not contamanated thanks for ur help

 

[blimp]

Re: 1983 35 hp johnson slips and revs real high

sounds like a slipping propeller hub. Try another propeller or get your hub replaced. You can test this by scribing a mark across propeller shaft to edge of hub and go for a trip on the lake. If the scribe marks don't line up, you need a new hub or prop.

 

[Grassman619]

Re: 1983 35 hp johnson slips and revs real high

Ok I'll try that I but when it first happened I did take off the prop and the teeth looked good but I never marked it. Is it easy to fix or dost it sound like I got a big problem???
Question The hub is in side the prop as one unit or is it the shaft it slides on to like the spindle

 

[Doug N.]

Re: 1983 35 hp johnson slips and revs real high

The hub is a rubber piece between the splined piece that goes on the shaft and the propeller itself. You need to go to a shop to replace the hub. The purpose of the hub is so that if you hit something the hub slips/breaks rather than tearing the blades off your prop.

 

[blimp]

Re: 1983 35 hp johnson slips and revs real high

http://forums.iboats.com/attachment.php?attachmentid=55149&d=1275499200

thanks to F_R for the image.

 

[Grassman619]

Re: 1983 35 hp johnson slips and revs real high

Ok thanks the picture helped so I took off the prop to mark it and when It came off the inner like end metal cap was off and the rubber at the top is chewed up so hopefuly this is it thanks

Question a spun prop means that the rubber hub spins faster then the blades right?? Or dose the the spline teeth have to be rounded out to be spun
I know it sounds dumb sorry I just want to understand thanks again

 

[blimp]

Re: 1983 35 hp johnson slips and revs real high

if the rubber is chewed up, the prop hub is likely the culprit. The inner metal splines match up with the propeller shaft, and they rarely get rounded. The reason it is slipping is the rubber has lost its friction with the outer part of the propeller, the part with the blades. When it slips, the inner metal part is spinning with the shaft/motor, but the outer blades don't spin. This results in the motor revving up, but the energy is not transferred to the prop blades, so your boat doesn't move very fast.

 

[Doug N.]

Re: 1983 35 hp johnson slips and revs real high

the rubber hub provides a mating surface so that everything turns at the same rate. Don't worry about the splines. Just get the prop shop to press the thing apart and press in another rubber hub, and its back to the lake for you! I ended up buying a spare prop because he shop couldn't support my fishing schedule. Life is spendy when you set priorities.

 

[Grassman619]

Re: 1983 35 hp johnson slips and revs real high

Ok thanks again guys I'll buy a hole new prop and tell u how it gose plus there's a few chips on the blads probley from when we went to the colorodo river haha but it all makes sence now I was scared it might of been something more serious like the gears in the lower unit or something this web sight is tons of hlep thanks again

 

[Grassman619]

Re: 1983 35 hp johnson slips and revs real high

Yup u guys were all right I replaced the propeller and the boat ran great but I found that I have an impeller problem

If it's not one thing it's another right

Thanks for all the help

 

[Al-53]

Re: 1983 35 hp johnson slips and revs real high

On your first post you said it overheated and you had it fixed...did they replace the water pump..if so..check to see if your hose or tell tale does not have a piece of the old impeller clogging it....take the hose of the fitting on the block also..if no water coming out run a wire in there to see if a piece of pump is not there blocking it....

Also if you have a prop shop near you...lots let you trade your old prop for a rebuilt one..your old prop and some cash and you get a nice rebuilt one...looks like new if its a good shop...


Al

 

[Grassman619]

Re: 1983 35 hp johnson slips and revs real high

Yeah my friends brothers boat / auto shop fixed up my motor but it took a hole year there did it as a side job for me the hole impeller and houseing was replaced cause the housing had spun and the rubber melted a little but now that u say something I'm guessing they didn't clean it out very good

Hey did go thru the hole motor replaceing all the gaskets he had said origainaly exhust was comming out the tailtail so the motor runs good now it's just the cooling system I'll try to pock the block for anything

And this week I'll change the impeller /and houseing

Question is there also a water pump or is that just what it's called

thanks for the help

 

[Al-53]

Re: 1983 35 hp johnson slips and revs real high

where the impellar is ..that's the water pump......I have the same motor ....its a easy job...the hardest part for me was lineing up the copper tube back in the water pump to not crush the new rubber gasket...

but like you said if the prior impellar melted you may have a clog some where...

Al

 

[Grassman619]

Re: 1983 35 hp johnson slips and revs real high

Well I unpulgged the talltail hose and poked around in the block and nothing I even blue into it and sucked out. it didn't seem colgged I blue the air and it was like no back pressure is it suppose to be like that??? It's as if it's an open hole on both sides with nothing stopping it in between idk is that bad