1975 135HP Intake Manifold

[Randyg123]

I pulled off my intake manifold and it looks good as far as i can tell. I've inspected the leafs and they all look good, Everything is real clean and I found no pieces of junk in there or broken parts.

I did notice an interesting issue in the lower port section (bottom most portion of the intake manifold. See the attached photos but it appears there is water mixed into the residual fuel/oil giving it that white creamy look like you might find in the lower unit when there's a water leak.

I am not sure if this is normal especially when I have not been running the engine much since I have been working on it and perhaps it is just condensation not being evaporated off on my last run.

Attached is a photo of the intake manifold with water droplets visible in the residual oil. The photo of the lower port section on the powerhead shows the creamy white oil/water on the bottom and in the channel. The other is a photo of the upper port section for reference (Sorry it's sideways).

Also are the ten bolts only suposed to be torqued to 60-80 in-lbs?

 

[Randyg123]

Re: 1975 135HP Intake Manifold

Seems some folks are back online this evening Bump^^^

 

[emdsapmgr]

Re: 1975 135HP Intake Manifold

You should not be seeing water on any of the engine internals. You need to find out where it is coming from before anything starts to rust/pit. It is unusual to see it in the intake manifold. I'd pull both heads and go looking form more water. You may have a bad head gasket or the bubble back exhaust covers could be leaking into the exhaust chest. Most exhaust gasket water leaks show up in the bottom cyl.

 

[Randyg123]

Re: 1975 135HP Intake Manifold

Been awfully busy so my past posts haven't been answered yet so please look up at those questions and offer any comments if you can.

Here is the final analysis after this weekend. I've got her all put back together and there was absolutely no change. If anything I made it just a little bit worse but I haven't spent the extra amount of time getting anal with the settings.

Here is what I did. I put on the new intake manifold gasket and carbs and flywheel. Improvised os TDC tool by using an adapter form my compression testor and a 3" #8 screw, nut, and butterfly nut. See attached photo. I rotated the flywheel until about 12 degrees BTDC and then screwed in the tool until snug against the piston head. Rotated the flywheel CCW until I hit the tool again at I assume about 12 ATDC. Mark the mid-point between these two marks and it lined up pretty much at TDC. Maybe about 1/2 degree or so off but close enough for improvising (i thought). I figure the tolerances of my method was probably greater than 1/2 degree so I left it alone and considered the timing pointer to be accurate. Opened the gaps on new plugs to about 0.035.

Adjusted the throttle per page 3-10 and throttle cam per 3-11. Set the timing per 4-11. Set right at about 5. Anything nearer to 6 and it would shut off. Five good, 5.25 okay, 5.5 starting to die, 5.75 instant off (no sputtering and fighting, just off - like turning the key to off). It was that sensitive. RPM while setting the timing was about 1650 on the muffs. at 5.5 the RPMs were still about 1500-1600. Would die at anything lower. Never got near 1100-1200.

Pulled the plugs, grounded out 2-4 and set a spark indicator on 1. Did the Joe Reeves method and set the WOT right at 16.

You can see the picture with the idle, timing, and cam yoke setting. As you can see, all are in just about all the way.

No changes observed from my condition of not wanting to idle. I haven't got it into the water yet, just running on muffs but no reason to suspect anything is different. My guess is that in the water it will not idle below 1100, just as before.

Now what??????????

 

[ezeke]

Re: 1975 135HP Intake Manifold

Service bulletin 1322 dealt with idle problems in the 1973 V4 engines. One thing mentioned was the improper sealing between the intake manifold and the crankcase, another was improper sealing on the intake bypass covers.

The bulletin is seven pages long so too much to post here. See if your service department has a copy.

 

[Randyg123]

Re: 1975 135HP Intake Manifold

Service bulletin 1322 dealt with idle problems in the 1973 V4 engines. One thing mentioned was the improper sealing between the intake manifold and the crankcase, another was improper sealing on the intake bypass covers.

The bulletin is seven pages long so too much to post here. See if your service department has a copy.

Thanks ezeke
Service Department? What's that? 'Round here, if you don't have something from this century, they don't want to talk to you. I'll see what I can find.

Do you think one of these issues would create the timing settings being so far off (the timing stop maxed out)? I don't want to keep chasing seals if it is meaningless. What's next, crankcase seals?

 

[harrietnorth]

Re: 1975 135HP Intake Manifold

Sounds like we are suffering from similar symptoms.

 

[Randyg123]

Re: 1975 135HP Intake Manifold

Sounds like we are suffering from similar symptoms.

Yes, very similar. I read your original post. About the only difference is that giving a little choke makes no difference for me. If you go through my hundreds of posts, you can see I've chased all the same potential issues as you plus I have ensured that the timing (from the timer base on) was correct and no-one tossed in a funky part.

Are your timing settings all messed up too? Do you have the WOT timer adjustment cranked all the way in to set your correct WOT?

 

[Randyg123]

Re: 1975 135HP Intake Manifold

You should not be seeing water on any of the engine internals. You need to find out where it is coming from before anything starts to rust/pit. It is unusual to see it in the intake manifold. I'd pull both heads and go looking form more water. You may have a bad head gasket or the bubble back exhaust covers could be leaking into the exhaust chest. Most exhaust gasket water leaks show up in the bottom cyl.

Thanks emdsapmgr for your post. Somehow I missed it. Oh goody, another gasket issue to chase after. why the heck not. I started at the carbs, went through the intake manifold, ezeke is saying the bypass covers, and now we have the exhaust or head.

The last time I ran the engine was for the decarb process using Seafoam. I ran the instructions posted here and then brought the boat back home. The next weekend, I ran the engine briefly on the muffs (with the lower unit submerged in a tub up to the cav plate. I just ran it for a few minutes to warm it up and check compression but the cowling cover would have been off. I was curious if these recent events created a temporary situation that may have created the water issue. What is the pathway the moisture takes? Is it internal or external pathway? Perhaps the Seafoam was pulling moisture out of my tank?

I will add that I have several times in the past checked for a potential exhaust leak (using the cowling cover on and off method to see if rpms changed). Never noticed a difference. Even had a mechanic check that and verified the same. However, I will say that after I performed the decarb using the spray bottle and was ready to run around to burn off the gas with more Seafoam, I thought I noticed a drop in rpm when I put the cowling cover back on. Could have been my imagination, maybe not. Perhaps now I have an exhaust leak after the decarb!!!

 

[Dhadley]

Re: 1975 135HP Intake Manifold

If you have water in the reflow system it may be a sign of water injestion. Water injestion can come from several sources but it will eventually be traced to water mist around the air intake (below the carbs and / or the top rear of the hood). The mist gets sucked in with the air. As the air & water enter the airbox some or most of the water will fall to the bottom of the silencer. At the bottom of the air box there is a hose that goes over to the intake. The water then goes thru the ststem just like gas & oil. Then it gets into the top and bottom main bearings. From there it starts getting into #1 and #4.

 

[Randyg123]

Re: 1975 135HP Intake Manifold

thanks Dhadley - Water Ingestion, huh. We call that drinking 'round these parts

I forgot to ask in my earlier posts. All those channels in the intake manifold and crankcase, are these to collect oil and then distribute around the leafs? I have read posts where people claimed they cleaned channels out and the screens as well. I never found any screens but I did shoot carb cleaner into each hole. A few did not seem to have an exit but most seemed quite clean.

Out of curiosity - what is the purpose of these holes/channels and how do they work?

 

[Randyg123]

Re: 1975 135HP Intake Manifold

thanks Dhadley - Water Ingestion, huh. We call that drinking 'round these parts

I forgot to ask in my earlier posts. All those channels in the intake manifold and crankcase, are these to collect oil and then distribute around the leafs? I have read posts where people claimed they cleaned channels out and the screens as well. I never found any screens but I did shoot carb cleaner into each hole. A few did not seem to have an exit but most seemed quite clean.

Out of curiosity - what is the purpose of these holes/channels and how do they work?

Can anyone enlighten me on this subject?

 

[Randyg123]

Re: 1975 135HP Intake Manifold

Can anyone enlighten me on this subject?

Still hoping for an answer to earlier questions.

Also what would the insurance for a 1973 Bass Boat with a 1975 135HP cost and how long would one have to wait before the boat...um...caught fire and sunk without the insurance company being suspicious? Just curious