johnson 140 intake/bypass vacuum hoses??

[fishdog4449]

How are these supposed to be connected? They go from four nipples on the intake manifold (which are oriented more or less under where each carb throat sits) to a nipple on each bypass cover, it looks like theres one for each cylinder from intake right to bypass..?? Or are they supposed to run from bypass on one side to intake on the other or something? I can't find anything about them in the manual.
Also, can this type of intake and carbs (later model) with the primer system be used with an older block?
Thanks!

 

[wilde1j]

Re: johnson 140 intake/bypass vacuum hoses??

OEM shop manual typically has four powerhead reference photos that shows all wiring and hose routing. I used to have an '85 140, but the shop manual went with the boat when I sold it. You must have a third party manual.

 

[fishdog4449]

Re: johnson 140 intake/bypass vacuum hoses??

yup, I've got the seloc

When I put the spare powerhead back on this boat, I used as much parts as possible from the 140 that has previously been on it, cleaned and tested first. Now I'm wondering if putting the later model carbs, intake, and transfer covers was a bad idea, not sure how though... they're both 80's crossflows. I had it out on the lake yesterday and it started and idled GREAT, maybe 650rpm in gear. Then go to give it gas and it sounds like its bogging and just doesn't take off, maybe 2000rpm at the most. Compression is perfect, spark is there on all four guess I'll have to test it further. Carbs and fuel pump were rebuilt too. Hm. I had just hoped i had the vacuum hoses on wrong...vacuum can play havoc with two stroke engines.

 

[clanton]

Re: johnson 140 intake/bypass vacuum hoses??

House routing was changed. use same routing as later model V4 90/115 for for the V4 crossflow engines. Better idle. I have diagram if I can fine it.

 

[ezeke]

Re: johnson 140 intake/bypass vacuum hoses??

On most of the 1980's V4 crossflows the small hoses run from the bypass covers to the recirculation check valves in the intake manifold.

 

[clanton]

Re: johnson 140 intake/bypass vacuum hoses??

This is for a later model engine, but should be the the same for your engine. Will improve idle. NOTICE the 2 upper nipples are connected to the center main bearing nipple, the 2 lower nipples connected to bypass covers. The changes were made sometime 1991 and recommend by OMC for the older engines.

 

[fishdog4449]

Re: johnson 140 intake/bypass vacuum hoses??

Thanks!!! where is the main bearing nipple? The only hoses on now run from intake to bypass.

 

[clanton]

Re: johnson 140 intake/bypass vacuum hoses??

Use Ezekes diagram, The diagrams I have must be for late model 80s. The center main bearing nipple would be on the side of the block and only 3 of the bypass covers would have the nipple.