1inch and 1 1/16th inch difference...

[relocyo]

i have this 1978 johnson 85hp outboard and it turns out there are 2 different size carbs on it ok so i just got the specs. one is a 1inch d-5 #323302 and the other is a 1 1/16 d-6 #323352... i mean one sixteenth of an inch is gonna make me have to buy all new carbs for this thing? please tell me thats not true... i can deal with not getting to WOT as this is just a little 15 footer and extremely light....
ultimately i just need to know if i can make these 2 carbs work together or not... and if not what other carbs will work ive found multiple online but i just dont know im about to pull my hair out!!

 

[jonesg]

Re: 1inch and 1 1/16th inch difference...

I don't know but lets bump you back to the top, someone will know.

 

[Tig]

Re: 1inch and 1 1/16th inch difference...

I have quite a bit of experience tuning and modifying two strokes but that's not what I do for a living. Here is my opinion on your situation;
First off, what are the stock carb specs? If you think the engine has been messed with you really need to know what is not to spec.
The bottom line is going to be your spark plug colour. If you can get 4 tan plugs (especially on a WOT test) you have got it set up well. At that point I doubt you could detect a difference in performance during everyday use. How does run now? Start well? idle nice? I'm not familiar with d5/d6 carbs. My father had an 85 back in the 80s, but I never played with it.
In general the following things come to mind.
With two carbs being larger you will have to sync the carb opening by airflow to ensure that it is even at all throttle settings. This is most critical at WOT.
I would also want to check jet size. just to see what differences I was starting with.
If tuning an engine is not your thing, then you may want to get matched carbs now and save yourself a piston later.

 

[nymack66]

Re: 1inch and 1 1/16th inch difference...

Here is my two cents for what its worth. Make sure its stock period. I posted the same question on another board in regards to my 87 140 v4 no replies was what I received. So with that said I proceed to buy a single brand new carb from the dealer just so I can compare low and behold it was the wrong size on my engine. Replace all back to stock and jetted to stock. Motor give me an excellent benchmark to work with a little fine tuning all it now runs like a new engine.
Good Luck .

 

[relocyo]

Re: 1inch and 1 1/16th inch difference...

thanks everyone for the responses... i just bought a new pair... got a great deal sooo... and didnt want to burn a piston.... fresh water carbs too!!! thanks again... i think it will be worth it... the way my buddy put it is "your gonna spend what you spent on the carbs one day having to get the boat towed home" i LOL'd

 

[Tig]

Re: 1inch and 1 1/16th inch difference...

I would have gone that route myself. Stock set ups are easier to own. You will be much happier.

 

[R.Johnson]

Re: 1inch and 1 1/16th inch difference...

Tell us where you are getting these measurment's. Look at the face of the carb, or inlet side at the upper right hand corner. Is it stamped, or in raised number's 1 5/l6?

 

[scipper77]

Re: 1inch and 1 1/16th inch difference...

i have this 1978 johnson 85hp outboard

... i can deal with not getting to WOT as this is just a little 15 footer and extremely light....

Sorry I can't help with the carb but this seems like a ton of motor for the boat. Assuming that that much motor is safe it must be a pretty peppy little rig. I can see where you aren't worried about WOT operation. I think I'd be scared to push that thing around at top speed. My 17' hits 50 mph and I've only ever gone that fast three times in four years just to see how fast it would go.

Good luck with the carb, we love pictures!!