1984 J90MLCRD- Four very small lines coming from crankcase to each carb. What gives?

[rebuilt]

I've got an older Johnson inline three that I'm intimately familiar with. An '89 60hp that was sank in saltwater and has been painstakinly completely rebuilt. Runs excellent. Then I get this opportunity to pick up a skiff equipped with an '84 90hp that hasn't run in 11 years. In the process of pulling carbs for a serious cleanup, I see this approximately 1/8" line coming from the starboard side of the intake manifold case. It then tees into a fourway that carries each individual line to a separate nipple underneath the carbs. Not being familiar with this engine at all, I looked at the sorry excuse for a manual that I have and found no reference to this tiny four way line. It looks just like primer solenoid fuel line. The line on this old motor is hard as a rock, I'm replacing all of them anyway. What is the purpose of this line? Oil return? Vacuum equalization? Something else? Can I plug the five fittings and move on? Or should I just replace the line? I'm dispensing with the VRO and going with a straight forward premix pump setup.Thanks in advance. Kevin

 

[rothfm]

Found this entry on another post:

It is a drain for unburnt fuel gathered at idle from the bottom of the reeds,
Through one way valves (screwed into the manifold) these may be nylon or brass. They run to the bypass covers and feeds the unburnt fuel in.

 

[spybot]

I dont think the lines you have are for the unburnt fuel. The ones you have are for the choke primer to add fuel direct to the intake (By-passing the throttle plates) Some of other engines have these pipes leading from the intake to the bypass covers. They also have the feed from the primer going direct to the bypass covers and feeding fuel in there.

 

[rebuilt]

Thanks for the reply. My choke solenoid only feeds two nipples, one for each carb. This line tees into a four-way. The excess fuel burnoff is the one that make sense. I'll just replace the lines. Thanks again. Kevin

 

[boobie]

Edit..........

 

[interalian]

Look on your inlet manifold for 4 little brass fittings (on the silver manifold on attached picture). If you have them you'll have a hose running from each one then over to the bypass ports on the side of the block. There may be minor differences in routing on the '84, mine's '82.

 

[rebuilt]

Bump from old post. I was OP so I'm not hijacking. I thought someone had answered this... This project has been on hold for about 3 years, so a 2 1/2 year old reply didn't ring a bell. Looking at interalian's pics, the manifold on the right doesn't have the brass fittings. Which leads me to believe that this is something J/E introduced to pull excess fuel back into the intake. Since the manifold on the right does not have this feature, it must not be absolutely necessary. I will do my best to unblock the fitting that is pressed into the crankcase, but if I can't get it to clear, I'll vacuum cap all of them.

 

[racerone]

Just be very , very careful when you decide to make changes.----The fitting on the side of the block leads to the center main bearing.----You do not want your motor to come to a " dynamic halt " do you ?

 

[rebuilt]

So.... the excess fuel mix that is pulled by vacuum back into the intake manifold actually helps lubricate the center main. The passage in the fitting seems blocked, plugged. I fitted a primer hose onto the red plastic nozzle that comes with carb cleaner and attempted to get some kind of flow through the fitting. No go. Looks like I might need to attempt to get the fitting out of the manifold with ruining it. Looks like the throttle-timing lever needs to come off to gain a little wiggle room with a pair of needle nose vise grips. We'll see how that goes........

 

[rebuilt]

After further fussing with this, the fitting in the pic is not coming out. Not happenin. And it looks like if I ham fist it and tear it up I'm screwed. But it is still blocked, Nothing flows either way, neither air nor carb cleaner. I took a torch tip cleaner and gently ran it into the fitting. The tip cleaner goes into the block approx 1/2", including the space the fitting takes. No flow. I blocked the intake with rags, put a primer hose on the fitting, stuck one end into a small glass full of premix and spun the motor for a good bit. Plugs out, water to the muffs, of course.Nothing pulled up out of the glass of premix. Right now I've got a weedeater fuel line hooked to the fitting and filled with seafoam, with the other end propped skyward in the hope that it might clear up the blockage. Really stumped on this one. Help is appreciated, as always.

 

[rebuilt]

So... after a full day of gravity fed sea foam the little fitting still won't clear. Does anyone know what is on the backside, the inside of this fitting? Does it fit into a cast journal-galley that then feeds the main bearing? Like a camshaft journal feeds oil to the cam bearings in a four stroker. Does it go into a one way check valve that may be blocked? What am I going to see if I pull the intake manifold and reeds? Will I be able to tell what is blocking this fitting? Can I drill it out so as to restore flow, or would that hit something on the inside of the case? Why did J/E not include this feature on interalian's '82? Doesn't the constant mist of premix from the reeds more than keep the mains good and wet? Way too many questions. No answers.

 

[rebuilt]

Just ordered intake the manifold gasket. I'm going to pull the intake so I can look straight into the starboard side block, maybe with a mirror. I'm not sure the excess fuel drain to block ever did function correctly on this engine. The fitting on the block HAS to breathe, or else there is no purpose in it. There is a 1/16", maybe 3/32" or so hole in the middle of it for cryin out loud. This morning I hand twisted a 1/16" drill bit into the fitting on the block as a last ditch attempt before taking the intake off. No progress, The fitting is still very much plugged. I went to the fiche on BRP's site. There is not even a drawing of the fuel overflow fitting that I'm obsessing over. The pressed in one on the starboard side. They showed the fuel overflow nipple on the intake, the four lines, the tiny plastic "T", no brass fitting on the front half of the block. And so it goes with a 36 year old engine that has more than a few PO's.