1983? Johnson 35HP lacking power/torque :

[Bosunsmate]

Re: 1983? Johnson 35HP lacking power/torque :

yes do a video. On mine i do just this as Haffiman said
"When roller and mark aligns, cam (carb) should start to open."

Mine doesnt touch the cam plate at the beginning too. Im not sure about prop but i can say its different to mine

 

[Mullerhawk]

Re: 1983? Johnson 35HP lacking power/torque :

I will as soon as I get the throttle control gear. I looked around, and 10x13 seems to be the best propeller for my boat. So the propeller is definently not the problem. 10x15 can be a bit steep though.

I found a service manual. And it states :

- Turn the speed control until the CAM wheel ligns up perfectly with the marking on the CAM.
- Loosen the throttle screw on the side of the carburator. Hold throttle close and fasten the screw again.
- Now throttle should open right after CAM wheel is passing the markings on the CAM.
- Adjust throttle control rod by putting it in gear and advance throttle until it is against cylinder stop (?? - full throttle I guess..)
- Push throttle control rod so carb is opening fully - move the small collar (by loosening and retightening the small screw)
- Adjust idle on the throttle control gear (small screw on the outside of the cowling)

Done!

 

[Haffiman]

Re: 1983? Johnson 35HP lacking power/torque :

Sounds the same. The only thing I would add is that using the idle adjust bracket and screw used on later versions and remotes that is attached to the exhaust cover is a better solution than using the screw on the gear. The screw on the gear gets easily bent and distorted. Further do not forget the mix screw. At lowest possible idle, adjust to max rpm (without touching the throttle), then back off about 1/2 out.

 

[Mullerhawk]

Re: 1983? Johnson 35HP lacking power/torque :

Sounds about the same as the 15hp I had before. Since I broke my throttle control gear I bought a new one (well - from a 50?s engine). The dimensions are correct, but the screw hole does not exist on this one. But as you said, it's easy to adjust on the throttle remote cable.

I will disamantle the whole carb and clean it. So i'll do the 1 1/4 turn on the mix screw when I put it back and go from there..

 

[Haffiman]

Re: 1983? Johnson 35HP lacking power/torque :

Do not attempt adjusting/fixing engine idle stop with the remote cable. Use the #11, #12, #13 from the adaptor kit!! Personally I threw away the original plastic screw and spring and used a SST screw and counter nut. The earlier version the bracket was alu, later SST.
http://www.marineengine.com/parts/j...p;+Tiller+Elec.&yid=34080&mid=34086&sid=38502
As for idle mix, start around 3-4 out, go in 1/4 at a time until max isle rpm reached (just before 'sneeze'), THEN back out 1/4!

 

[Mullerhawk]

Re: 1983? Johnson 35HP lacking power/torque :

Update: New throttle conrol gear fitted, link-and-sync performed. Did a test drive yesterday. Now it went from 16 knots to 21 knots which is a huge improvement since now you feel that the power and revs are there. Unfortunentally its a 25" rig. So the cavity plate is way under the boat. With a 15" I would guess that the boat would do 25 knots. But hey! Can't win em all .

It's a bit touchy to get the idle right. I have turned the idle screw on the throttle control gear fully in. And adjusted the idle on the carb. It idles bareley and tends to die when I put it in gear. Any ideas how to archive a bit more throttle when ideling? Should I put in a longer screw in the gear?

 

[Bosunsmate]

Re: 1983? Johnson 35HP lacking power/torque :

I normally do the idle on the water with the gear in forward so it wont die when put into gear.
You could put a jackplate on to the transom to get the anticavitation plate up to the proper level. I made one the other day, it took about an hours work. Four sheets of marine ply with epoxy resin in between and then finished in white paint. Not only do you get the extra power but you dont get the extra backpressure on the exhaust too

 

[Mullerhawk]

Re: 1983? Johnson 35HP lacking power/torque :

Do you have a photo to show? Would be interesting to do this as a winter project and see if there is any difference in performance.

 

[Bosunsmate]

Re: 1983? Johnson 35HP lacking power/torque :

Heres a photo of the one ive just done, its for a smaller motor than your one but the principles are the same, ive seen them on motors up to 90hp and theres nothing i can think of that would stop them going on higher rating motors than that too.
Be sure you get large washers to go on the Stainless steel bolts to hold it onto the transom. Also press the ply together with weights as you seal it with resin to get the air bubbles out. This one of mine still needs the bottom edge there sawn straight for looks not function and also the holes drilled so it can be bolted to the transom.
Some people fill those holes with epoxy resin as they install the bolts so water cant seep in through the washers or somewhere else
You can use a few materials for a jackplate, i find marine ply and epoxy resin good as you can custom make the width and its easy to saw etc, i had all those materials here on hand so thats what i used but with the Swedish winter im guessing you will have some time to plan it and really make it suitable to your boat for performance and make it look good.
I will be interested to see a photo of one on a Johnson 35hp if you end up doing one.

 

[Mullerhawk]

Re: 1983? Johnson 35HP lacking power/torque :

Another thought I had was using two U-beams of aluminium and bolt them to the transom with stainless bolts and then use two more smaller U-beams to run inside of these with holes drilled on differens hights to be able to move it up and down manually.

 

[Haffiman]

Re: 1983? Johnson 35HP lacking power/torque :

Replace the idle control/adjust screw in the gear with the newer version attached to the exhaust cover. Bracket #11 in diagram. The newer brackets are in SST, so just use a SST screw and counter nut.

 

[Bosunsmate]

Re: 1983? Johnson 35HP lacking power/torque :

Another thought I had was using two U-beams of aluminium and bolt them to the transom with stainless bolts and then use two more smaller U-beams to run inside of these with holes drilled on differens hights to be able to move it up and down manually.View attachment 171235

Good idea, patent it