1988 60 lean carbs and 70hp carb question

[lowebo]

OK first off I have not had the motor long (got a deal) but it has a bad lean condition on the #2 and #3 carb compression is #1 143 #2 135 #3 137. Its so lean it will sneeze and cutoff, carbs had been rebuilt before my buying and look to be so inside and out(maybe not dipped) BUT if I squirt gass into the 2 lean carbs it will pick up speed and revs fine for a couple seconds until in runs back out the (top carb has no change or will slow down).. same thing if i use the choke. I shot all the passages like heck with carb cleaner and everything looks to be open. I had to advance the timing to 4deg (only running in a tank) just to get it not to sneeze.

So I have a perfect runing 2001 Johnson 70 I switched the carbs from and a couple things came about. First thing is now it runs extreamly rich and idles rough and idles very low @4 deg. The second thing is the sneeze is compleatly gone but nothing I do will speed up the idle. I had always herd of people using 70 carbs on 60s with no issue but are the later carbs diffrent? Also is there somthing else that could be causing this that is NON-carb related. At first glance to me the simple man it looks to be all carb related but thats why im here. I have found some Other 60 and 70hp(one nice set of 70s) carbs around but want to cover all the bases before making any moves that could be wrong ones. The reeds look excellent and starter fluid has found no intake/crankcase leaks.

Anything you guys can offer is appreciated!

 

[boobie]

Re: 1988 60 lean carbs and 70hp carb question

I would say take the 60 hp carbs and go through them with a fine tooth comb, checking all circuits for being open. Then instell new carb kits. I believe the jetting is different on the 70 hp.

 

[lowebo]

Re: 1988 60 lean carbs and 70hp carb question

There seems to be a diffrent intake/Carb part # on the 91 and later motors. Anyone know if the 90's modle carbs are compatable on a 1988 motors besides the jets? I also read some place about cubic inch diffrences playing a role in diffrent carb jeting.
Just wanting to know b/k the carbs I have look as though they spent a little to much time in the acid, there is bad pit marks under the welch plugs on one.

Thanks again!

 

[water world]

Re: 1988 60 lean carbs and 70hp carb question

if i remember correctly. i worked for omc dealer and there was a jet kit to update your engine,.. make sure the top plastic covers on top of card are not warped ...

 

[lowebo]

Re: 1988 60 lean carbs and 70hp carb question

My carbs I have now have the solid body with no covers and fixed air jets. Thats what im trying to learn is will the later ones like your speaking of work on the early (1988) motors.
Thank boobie and waterworld for you advice...more is always welcome....from anyone!

 

[5150abf]

Re: 1988 60 lean carbs and 70hp carb question

10 gallons of Carb cleaner won't clean a dirty jet, you need to actually remove the jets from the carb and run a wire through them, they may look clean but aren't and nothing you do will make the engine run until you do this, you are describing tha classic symtoms of glogged main jets, the reason it runs better when you spray gas or hit the choke is because that makes up for tha gas the carb isn't giving it because the main jets are dirty.

I went through this a few years ago, "cleaned" the carbs didn't work, changed CDI, nothing, changed coils, nothing, rewired engine, nothing, cleaned carbs again correctly and it ran like a champ.

At least after you run a wire through them and all the carb pasages you will be able to rule the carbs out out, if you don't have a compressor use the air in a can, it works just as well.

 

[boobie]

Re: 1988 60 lean carbs and 70hp carb question

5150, you said what I meant by "a fine tooth comb".

 

[lowebo]

Re: 1988 60 lean carbs and 70hp carb question

emulsion tubes on #2 and 3 were cracked BAD across the tube(open cracks) where the little tiney hole is just below where it enters the carb throat. this thing is wide open everywhere and I have built plenty of carbs and never had anything this clean and run this lean. They have new kits in them but based on what I seen on the tubes I went on and picked up another set of ebay and 3 new kits. Hope that will fix the prob!

Thank's for the help