Right carb for 1975 135 HP Johnson

[Randyg123]

It has been brought to my attention that I may have the wrong carbs on my engine. How can I confirm exactly what carbs on are this engine? Since the stern mount had a different ID (73 85HP) it is possible that I could have carbs from an 85HP on this engine. Is there a difference between these two carbs?

 

[tashasdaddy]

Re: Right carb for 1975 135 HP Johnson

you can compare here.

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

you can compare here.

By here, do you mean on this forum, or did you mean to post a link?

If on the forum,
What information will be required from me to post to help all you experts?

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

So what do I need to do to figure out what carbs I've got on this thing?

 

[Dhadley]

Re: Right carb for 1975 135 HP Johnson

There really aren't "wrong" carbs. You can use any V4 or V6 carbs from 1973 on. (You'll have to do a tiny mod to use a V6 carb) Look on the front of the carb body and you'll see a venturi size. Something like 1 5/16 or 1 1/4 or something like that. Truthfully we found that the late model 1 1/4" carbs work pretty darn well on just about any recreational v4 crossflow.

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

There really aren't "wrong" carbs. You can use any V4 or V6 carbs from 1973 on. (You'll have to do a tiny mod to use a V6 carb) Look on the front of the carb body and you'll see a venturi size. Something like 1 5/16 or 1 1/4 or something like that. Truthfully we found that the late model 1 1/4" carbs work pretty darn well on just about any recreational v4 crossflow.

Thanks for the reply.

So what you are saying is, two wrongs do make a right

Exactly where on "the front of the carb body" will I find this? Do i need to remove the silencer to find the venturi size? I couldn't find a part number tag.

Even with the fixed jets, there is nothing to worry about regarding different carbs?

 

[iwombat]

Re: Right carb for 1975 135 HP Johnson

Yes, remove the silencer and it'll be just below the . . . um . . . right (?) venturi opening as you're looking at it.

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

Yes, remove the silencer and it'll be just below the . . . um . . . right (?) venturi opening as you're looking at it.

Right is was

Both carbs #319671 1-5/16

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

So if both carbs are 1-5/16", does that mean they are the correct carbs for this engine? Or are there different jets/orifices that go into these carb bodies for the various engines.

I have brought this motor in for two tune-ups since I acquired it. I don't know what they did when re-building the carbs during this process. But since the stern mount showed a different model (73 85HP) would they have just bought a carb kit for that engine and installed into my carb without realizing that the engine was really a 135HP?

What is the general procedure on how a repair facility would handle a tune-up? Would the go by what the ID says on the mounting bracket or would they noticed a discrepancy and replace to meet the specs as the motor came in the door?

If the carb was re-built as an 73 85HP, would that create a problem since it is really a 75 135?

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

I re-phrased my questions in the above post. Hopefully the questions make more sense now.
Thanks

 

[iwombat]

Re: Right carb for 1975 135 HP Johnson

Those carbs are just fine for that motor. The only thing that needs to happen if they're not stock is to re-jet for the application. The rebuild kits do not include jets.

How do the insulators on your plugs look - light tan, white, or charcoal black?

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

Those carbs are just fine for that motor. The only thing that needs to happen if they're not stock is to re-jet for the application. The rebuild kits do not include jets.

How do the insulators on your plugs look - light tan, white, or charcoal black?

Sorry, I missed your post. The insulators have a light tan color assuming you are referring to the part exposed to the combustion.

 

[iwombat]

Re: Right carb for 1975 135 HP Johnson

Light tan means it's all healthy.

You're good to go.

BTW I'm pretty sure the carb kits are all the same for the different sized carbs. No difference between the 85hp and the 135hp kit.

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

Kewl!

That would be so comforting to know that I don't have to worry about the carbs (wrong part) being a problem. I think I will just tell the mechanic to put in the correct jets for the 135 while he is re-doing the carbs (again).

 

[iwombat]

Re: Right carb for 1975 135 HP Johnson

Jets are sized for the carb body. So, if you're unsure about those carbs, putting in the stock jets could be a bad idea. It's running fine as-is (indicated by the plug color), why fix what isn't broke?

 

[emdsapmgr]

Re: Right carb for 1975 135 HP Johnson

Not sure if you have an 85 hp block or a 135. Does the engine have a flat exhaust or does it have the bubble exhaust? The 135 would have originally come with the 1 5/16" carbs. The high speed jets from a 75 135 would have been .061. All crossflow carb kits are the same for this series of engines, regardless of hp. During a rebuild, the tech will clean, but usually never replace jets.

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

Thanks guys,

I am still trying to get this thing to idle. It won't. I've gone through everything else (see my other posts).

She's a bubble-back. Thanks to a comment from wavrider who caught that, I never would have even known I had a 135HP.

I am just trying to cross off all possibilities for problems and wondering if someone slapped on some carbs from an 85 on to this engine but did not bother to make any necessary adjustments/replacements (if any). From the comments received, it appears that the carb bodies are the same but there could be a difference in the jets (high, low, or both). Since she doesn't want to run slow, I am hoping there may be a difference in the low-speed jets and I have the wrong ones making it run rich at low speed Really wet plugs if idling for more than a few minutes).

 

[iwombat]

Re: Right carb for 1975 135 HP Johnson

The idle orifices on the '75 show up as #30s. My guess though is that you've still got dirty idle jets or perhaps an air leak or even something else entirely going on.

Now that we know the carb bodies probably aren't an issue it's time to start at square 1 and do compression and spark checks.

 

[Timmstng67]

Re: Right carb for 1975 135 HP Johnson

Hi
My 1977 140 was running rich at slow speed and idle and I found that I had the floats out of adjustment after rebuild of carbs. I reset the floats correctly and it fixed my problem.

 

[Randyg123]

Re: Right carb for 1975 135 HP Johnson

The idle orifices on the '75 show up as #30s. My guess though is that you've still got dirty idle jets or perhaps an air leak or even something else entirely going on.

Now that we know the carb bodies probably aren't an issue it's time to start at square 1 and do compression and spark checks.

Compression and spark are good (150+/- and 7/16").
Perhaps square two is appropriate

I think I am going to take her in to the mechanic that worked on it and ask for the carbs to be re-done. If you recall, the lower carb had a small leak or possibly (your diagnosis) a float problem since the gasket was always wet and fuel puddling below. Plus I am missing the carb-to-silencer gasket on the lower carb. I will have him confirm the jets on these carbs when they are re-built. do they normally pull the jets out and inspect during a carb job or do they just run a wire through them?