Milky fuel in carb intake force 85hp

lgaytan

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Main jet for sea level-2500 FT should be 0,074.
2500-5000 FT should be 0,072.
It will not run well with a too small main jet.
I do not know if this have anything to do with your issue, but it will run lean with a 0,072 at lower sea level.
Think your main issue is water intrusion in 3 and 4 cylinder.
Agree I don't think the Jets are what is causing me the current issue, just wondering why it have more issues starting it at the lake than at home. I don't know what jets it has but I guess they are 0.074 as there are no lakes near my location and this boat has always been used at lower altitudes.
 

racerone

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Outline your starting procedure in detail.----Is the battery good and load tested.-----Is the starter motor tested and in good condition ?
 

gica

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Thanks, maybe I didnt explained myself very well, I can pull the throttle lever to accelerate without engaging the gears, this is I guess a function for cold starts, in that way I can accelerate up to 1600 RPM's that is the maximum it allows me to do with this function, everything looks good there with the hose or tank, very different in the lake. Now also I don't know how important is but my home is 4900 feet above sea level and the lake I use to go is roughly 1500, I usually have more issues starting it in the lake than at home, settings should be different I guess for this different altitudes.
So using the throttle only function and pushing it all tye way briefly in your little tank out of gear you only get 1600RPM?
I don't know if that is any better then 1200 in gear on the lake. Kind of the same. You shouldstick an endoscope camera after running it and look at tye pistons to see if you have any water. Here is a picture of mine. It's the number 4. The motor ran by itself was bogging down severely. Sounding like it was coughing up flam hahaha.
That altitude deal I am not sure about. Was your boat equipped for high altitude or not? I took a 97 Bayliner I/O carbureted to Lake Tahoe 6200 feet and I was ok with stock carb adjustment. So that should not prevent you from getting higher RPMs
 

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lgaytan

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Outline your starting procedure in detail.----Is the battery good and load tested.-----Is the starter motor tested and in good condition ?
Hi, racerone I usually put the throttle lever to Max accelerate out of gear, push the choke and keep it pushed while cranking. Battery and starter are in good condition, I see and hear them spinning at good speed, I was just mentioning that I see a difference in the cold starts in this different locations, not sure if the set up of the carbs or something has to be adjusted differently in each of them, I guess that is something I will have to deal living far away and in different altitude than where I can actually use my boat.
 

lgaytan

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So using the throttle only function and pushing it all tye way briefly in your little tank out of gear you only get 1600RPM?
I don't know if that is any better then 1200 in gear on the lake. Kind of the same. You shouldstick an endoscope camera after running it and look at tye pistons to see if you have any water. Here is a picture of mine. It's the number 4. The motor ran by itself was bogging down severely. Sounding like it was coughing up flam hahaha.
That altitude deal I am not sure about. Was your boat equipped for high altitude or not? I took a 97 Bayliner I/O carbureted to Lake Tahoe 6200 feet and I was ok with stock carb adjustment. So that should not prevent you from getting higher RPMs
Thanks I will order an endoscope to take a look, having the haead leaking the first time I started up also makes me wonder, although right now I'm leaning more to the fuel pump issues but I guess is good to look every aspect of this "rebuild".
 

lgaytan

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So I finally got the pump diaphragm, valves and some gaskets I thouvht were bad and rebuilt the pump, it fired up very quickly sounds good on muffs 1200 RPMs no issues would not Rev up more on muffs. I didnt get the boroscope so I rather took off the head again to have a look after warming up the motor, I did noticed some drops of water on cylinder 2 and 3, but they are perfect clean drops so I dont think they come from a leak, I think they just got there when taking the head off and some water comming from the block, there is no milky stuff I can see the fuel there is very blue so I think is no contaminated, what do you think?

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gica

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So I finally got the pump diaphragm, valves and some gaskets I thouvht were bad and rebuilt the pump, it fired up very quickly sounds good on muffs 1200 RPMs no issues would not Rev up more on muffs. I didnt get the boroscope so I rather took off the head again to have a look after warming up the motor, I did noticed some drops of water on cylinder 2 and 3, but they are perfect clean drops so I dont think they come from a leak, I think they just got there when taking the head off and some water comming from the block, there is no milky stuff I can see the fuel there is very blue so I think is no contaminated, what do you think?

View attachment 398821
Here is a picture of piston 4 on mine through a scope. At tyecenter you will see the clear water bubbles that look pretty clean. The milky stuffwasin the exhaust area on mine.
 

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lgaytan

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Thanks gica, it looks different to me eyes yours and mine, I'm gonna take a shot and take it to the lake again, hopefully it was only the pump. Crossing my fingers.
 

lgaytan

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Got back to the lake again, changing the fuel pump diaphragm didn't did any difference, this time I went with my father, he knows some mechanics he suggested to open the carb needle a little bit I didn't tried that before because it idled good and I thought that needle only worked in idle, anyways they were close to 1 turn and we got them to 1 1/4 turn it immediately felt better I was able to manage 2000 rpms before stalling, If I kept trying to accelerate the motor stalled, I opened them another 1/8 of turn and I was able to accelerate a bit more didn't stalled but still didn't felt very good, I stopped there I went also with my 3.5 year old son and wanted to have him on the boat and try to fish something, so we did some trolling and he finally saw his first bass! I will keep now tweaking the carbs for next time, maybe do a full clean up and then adjustments.
 

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jerryjerry05

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The air screw is for the air fuel mix at idle or close to idle.
Past 2000 the main jet takes over.
Try cleaning the carb and make sure all passages are open.
While the carbs are off: look in at the reeds and make sure they are closed or close to being closed. A small gap is acceptable.
 

Jiggz

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This is a long thread. Anyways, when you did the Link and Synch, at WOT (engine off and control handle all the way forward) were the throttles (butterflies at the throat of the carb and NOT THE CHOKE BUTTERFLIES AT THE FRONT) at full horizontal? If they are, when you accelerate, does the priming bulb collapses just before the engine dies? Have you tried priming (depressing the priming bulb) it when accelerating just to see if it goes any higher rpm? I'm suspecting it is a fuel related problem. So as mentioned check the carbs and while at it check the reeds also. But next time you go to the lake, take note of the priming bulb, it could be the culprit with a stuck check valve. It's not unusual at all. Better yet get a new fuel hose/priming bulb and use an external fuel tank and see if that'll fix your problems.
 

lgaytan

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Hi Jiggz we did check on the primer bulb that was a common issue in other boat so now almost every time something fails that is one of the first things we check, I believe it is not the issue it does not collapses and stays firm all the time, if you try to press it when its starting to die it makes no difference, that bulb is quite new less than a year, I also changed almost all hoses and check that all clamps are tight, we are running with an external tank also to try to see easier if theres any issue there, I definetely now believe the issue is in the carbs based in what happened yesterday, will make the clean up and needle adjustments.

Thanks
 

Jiggz

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Hi Jiggz we did check on the primer bulb that was a common issue in other boat so now almost every time something fails that is one of the first things we check, I believe it is not the issue it does not collapses and stays firm all the time, if you try to press it when its starting to die it makes no difference, that bulb is quite new less than a year, I also changed almost all hoses and check that all clamps are tight, we are running with an external tank also to try to see easier if there's any issue there, I definitely now believe the issue is in the carbs based in what happened yesterday, will make the clean up and needle adjustments.

Thanks
Great. So now we can rule out the fuel hoses, priming bulb and clogged suction fuel pipe. Have you installed a clear fuel filter between the fuel pump outlet to the carbs' inlet? This is a very good and cheap troubleshooting tool for fuel related problems. A $5 Fram G2 or G3 will suffice.

Carb cleaning and adjustment should be your next step. Be very careful with these carbs as they are almost 40 years old and can be very fragile and replacement parts are hard to come by. It's not unusual but with three separate carbs and one malfunctioning should still allow the engine to run albeit rough or misfiring. Now if two carbs malfunction, that will definitely stall the engine. Since the engine idles fine, I will focus on the main jets and then the float position.
 
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lgaytan

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Great. So now we can rule out the fuel hoses, priming bulb and clogged suction fuel pipe. Have you installed a clear fuel filter between the fuel pump outlet to the carbs' inlet? This is a very good and cheap troubleshooting tool for fuel related problems. A $5 Fram G2 or G3 will suffice.

Carb cleaning and adjustment should be your next step. Be very careful with these carbs as they are almost 40 years old and can be very fragile and replacement parts are hard to come by. It's not unusual but with three separate carbs and one malfunctioning should still allow the engine to run albeit rough or misfiring. Now if two carbs malfunction, that will definitely stall the engine. Since the engine idles fine, I will focus on the main jets and then the float position.
I had one of those filters before but took it out, I will put a new one now. I have another lake trip this weekend so I need to do this cleaning during this week to have the chance to go there and test. I'll post results.
 

lgaytan

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The air screw is for the air fuel mix at idle or close to idle.
Past 2000 the main jet takes over.
Try cleaning the carb and make sure all passages are open.
While the carbs are off: look in at the reeds and make sure they are closed or close to being closed. A small gap is acceptable.
Forgot to mention when I was in the rebuild process I took a look to the reeds and all seemed to be closing except for one, you could see a tiny light through, but I believe its in the acceptable range.
 

Jiggz

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I had one of those filters before but took it out, I will put a new one now. I have another lake trip this weekend so I need to do this cleaning during this week to have the chance to go there and test. I'll post results.
On your next trip to the lake, try running the motor without the cowling cover and see if this makes a difference. And at the same time able to see the fuel filter if it stays at least half full. Other thing to watch for, the tower linkage movement with the carb ties and those wires that runs to the stator and trigger. It's possible at a certain position, a wire or two is rubbing against ground, thus stopping the engine.
 

lgaytan

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Last time I did run without the cowling cover and I noticed it ran better with out it, I don't know if that is better air flow but of course it is intended to run with the cover so I put it back again.
Will take a look to the wires you mention in the stator and trigger.
 

Jiggz

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Last time I did run without the cowling cover and I noticed it ran better with out it, I don't know if that is better air flow but of course it is intended to run with the cover so I put it back again.
Will take a look to the wires you mention in the stator and trigger.
"It ran better . . ." does that mean it ran fully at WOT? or at least attained 4000 RPM? If so then the problem could be exhaust leak. But it is rather hard to diagnose exhaust leaks on the driveway unless you are using a large barrel of water. Using a garden hose alone will not identify the exhaust leak. So you might want to include that in your check list on your next trip to the lake. Exhaust leaks usually by the upper and bottom connection, exhaust manifold or even the exhaust relief hose (two holes at the back of the mid-leg.
 

lgaytan

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Not to WOT just felt better I didn't checked the RPM's at that time but will take a look on the weekend, thanks for all this tips.
 

lgaytan

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I was reading some old posts regarding the exhaust leak, some items they mentioned to check is the idle exhaust boot #5 that one is good, I changed it recently prior to this work I will check that I installed it correctly as this is a hard thing to put, the one thing that I know for sure is bad is the seal I marked in the image below, that one was completely carbonized and thorn but I didn't see a part number in the marine engine website so I thought it was not that important, I kind of put some electrical tape to be able to hold it into place and make the installation but for sure that thing is not sealing much or anything... I will make the test without the cowling cover this week end but for sure that thing is bad.

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