Cylinders Low In PSI ? (HELP)

[Weep'n Willy]

Re: Cylinders Low In PSI ? (HELP)

I too am a bit miffed by this thread. It seems op is looking for help but wants to do things his way. Rushing to send a block off to Canada without knowing what needs done. Then doing some test half assed. Maybe in a hurry and expecting instant results.

First and foremost:

What has changed with the way the engine was running? Noise, smoke, power loss, etc.......Write it down.
Test components completely and properly before tearing down engine.
Compression test: Test all cylinders - not just a couple
Wet test: Again test all cylinders - not just the ones that seem to have low compression
Leak Down test: Again, all cylinders, not just a couple. Write down results.

A good baseline gives you an idea where a problem may lie and then you can begin your plan of action. If you don't understand the results of your testing then at least you can post information that others can decipher and help you with a plan. Obviously this site has some very talented individuals with a lot of experience to help you out. Without a basic knowledge of engines and engine building you are basically pissing in the wind.

If you are serious in your interest to diagnose and rebuild engines I would suggest you check into the local VoTech schools as some have evening classes on engine repair and would be worthwhile to give you a good fundamental background into engine theory, diagnosis, and repair.

Not trying to bust your gourd but I have seen too many backyard "mechanics" pour money into an engine only to have it give up the ghost.
Good luck with your project.

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

I too am a bit miffed by this thread. It seems op is looking for help but wants to do things his way. Rushing to send a block off to Canada without knowing what needs done. Then doing some test half assed. Maybe in a hurry and expecting instant results.

First and foremost:

What has changed with the way the engine was running? Noise, smoke, power loss, etc.......Write it down.
Test components completely and properly before tearing down engine.
Compression test: Test all cylinders - not just a couple
Wet test: Again test all cylinders - not just the ones that seem to have low compression
Leak Down test: Again, all cylinders, not just a couple. Write down results.

A good baseline gives you an idea where a problem may lie and then you can begin your plan of action. If you don't understand the results of your testing then at least you can post information that others can decipher and help you with a plan. Obviously this site has some very talented individuals with a lot of experience to help you out. Without a basic knowledge of engines and engine building you are basically pissing in the wind.

If you are serious in your interest to diagnose and rebuild engines I would suggest you check into the local VoTech schools as some have evening classes on engine repair and would be worthwhile to give you a good fundamental background into engine theory, diagnosis, and repair.

Not trying to bust your gourd but I have seen too many backyard "mechanics" pour money into an engine only to have it give up the ghost.
Good luck with your project.

I have done all the test but the wet test. I will do that one soon. I mean i have worked on boats before with great success. Just never really went into detail with the marine engines. I am what you would call a DIY person. Some people could be just as good as a certified mechanic but without a degree or a school education only on mechanics and i am hoping to be one of them. I have done very difficult stuff like rewiring a jetski or boat and rebuild a out drive or so. I mean i am not totally mechanically stupid. I am really not doing things my way because mainly i have no game plan for it so thats why i attend to the smarter individuals in mechanics to help me out. My original plan was to get it fully rebuild top to bottom. But now i may reconsider it since it may just be a blown head-gasket or a valve issue. Try and save a bit money if i can.

 

[achris]

Re: Cylinders Low In PSI ? (HELP)

To all the detractors...

Your negative comments are not helping. If you have constructive or helpful comments and suggestions, please feel free to post them, but if you just want to dig up the past or tell someone how much of a fool they are, keep them to yourself.

He's here asking for help. So let's do what iboats does best, give help.

Thank you.
(If you have comments regarding this post or the rest of this thread, PM me, don't post them in this thread. Thank you)

 

[Weep'n Willy]

Re: Cylinders Low In PSI ? (HELP)

Dog, don't get me wrong....... I wasn't implying you were inept, just merely passing on basic steps toward assisting in diagnosing engine problems whether it is a marine, automotive, or any other engine, the steps are basically the same. The more info you have to start with results in less cost and successful completion. Again good luck with your project.

 

[xjdriver]

Re: Cylinders Low In PSI ? (HELP)

So whens the leak down test goin down?

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

Dog, don't get me wrong....... I wasn't implying you were inept, just merely passing on basic steps toward assisting in diagnosing engine problems whether it is a marine, automotive, or any other engine, the steps are basically the same. The more info you have to start with results in less cost and successful completion. Again good luck with your project.

No i totally understand and i will follow everybody's advice. And thank you for the luck! I will need alot of it. Thanks again for commenting!

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

So whens the leak down test goin down?

Ahhh hopefully this Saturday Or Sunday or next. Its usually when i have the free time for a 2 hour trip to get to my boat. :joyous:

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

The issue is that I have read through the whole thread, maybe you should too! Then at least your story may be consistent.

Personally, I am looking away from the train wreck. Carry on my friend, I wish you luck in your endeavors.
Gator

Ok thanks again for your participation in this thread.

 

[Fun Times]

Re: Cylinders Low In PSI ? (HELP)

So whens the leak down test goin down?

Unfortunately the boat is about an hour or two away from him at his brothers place for storage mainly due to lack of room to store a bigger boat like that at his place in Brooklyn New York.

So this has become a weekend winter project for him and unfortunately at this time he has yet to establish a game plan of what steps he needs to do by way of pulling the engine or is there enough room to work and pull the heads off inside the boat.

He's redone a thorough enough compression test after guidance from our iboats members both on the forum and by private message to him directly. Mainly the private message were done in order to help keep the truthful conversations inline and to avoid any stray conversations/stories from hitting the forums in turn wasting any of our iboats members time from trying to honestly help out. Big Dog now knows and understands that wasting our time cannot and will not be tolerated here and while most of the moderators here are both helping him the best we can all the while giving him one last chance to make his past wrongs right again while remaining on a reasonable short leash.

So far he has been on a much better track than before at doing his best at giving it to us a straight as he can/knows how and we appreciate that.

While a leak down test would be nice to have one done already he has not had a chance to do one and he fully understands that. But whatever the case turns out to be, one of his main objectives is going to become how he is going to be able to pull the heads off which at this point in time it seems pretty clear that this is going to have to happen once he does a thorough inspection to the valve train under the valve covers first.

Please bear with him over the winter as this may turn into one of iboats longest running engine threads in iboats history. Thanks for your patience guys, it is truly appreciated.

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

To all the detractors...

Your negative comments are not helping. If you have constructive or helpful comments and suggestions, please feel free to post them, but if you just want to dig up the past or tell someone how much of a fool they are, keep them to yourself.

He's here asking for help. So let's do what iboats does best, give help.

Thank you.
(If you have comments regarding this post or the rest of this thread, PM me, don't post them in this thread. Thank you)

Thank You Chris!! :joyous:

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

Unfortunately the boat is about an hour or two away from him at his brothers place for storage mainly due to lack of room to store a bigger boat like that at his place in Brooklyn New York.

So this has become a weekend winter project for him and unfortunately at this time he has yet to establish a game plan of what steps he needs to do by way of pulling the engine or is there enough room to work and pull the heads off inside the boat.

He's redone a thorough enough compression test after guidance from our iboats members both on the forum and by private message to him directly. Mainly the private message were done in order to help keep the truthful conversations inline and to avoid any stray conversations/stories from hitting the forums in turn wasting any of our iboats members time from trying to honestly help out. Big Dog now knows and understands that wasting our time cannot and will not be tolerated here and while most of the moderators here are both helping him the best we can all the while giving him one last chance to make his past wrongs right again while remaining on a reasonable short leash.

So far he has been on a much better track than before at doing his best at giving it to us a straight as he can/knows how and we appreciate that.

While a leak down test would be nice to have one done already he has not had a chance to do one and he fully understands that. But whatever the case turns out to be, one of his main objectives is going to become how he is going to be able to pull the heads off which at this point in time it seems pretty clear that this is going to have to happen once he does a thorough inspection to the valve train under the valve covers first.

Please bear with him over the winter as this may turn into one of iboats longest running engine threads in iboats history. Thanks for your patience guys, it is truly appreciated.

Ok thank you Fun Times!! So with that being said i do indeed have enough space to work on the engine and get the head off ect ect. I will preform this leak down test when i have the free time which is usually on Saturday or Sunday. The biggest problem is that the distance it takes me to get to the boat is about 65 miles which is about 2 hours in travel time in the NewYork traffic. All of my operations to the boat are done every other Saturday or Sunday because simply i cannot burn gas ever time going back and forth from there. So if all you guys can just bare with me here and i promise you the results you guys are looking for so then later we can all celebrate. Thank You again and all your helpful advice is greatly appreciated by me and the moderators. ! Have a good one :joyous:

 

[WIMUSKY]

Re: Cylinders Low In PSI ? (HELP)

To all the detractors...

Your negative comments are not helping. If you have constructive or helpful comments and suggestions, please feel free to post them, but if you just want to dig up the past or tell someone how much of a fool they are, keep them to yourself.

Not that achris needs my help, but, his opinion mirrors my own. Let's be as helpful as we can w/o being critical.

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

Not that achris needs my help, but, his opinion mirrors my own. Let's be as helpful as we can w/o being critical.

Thank You Again!

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

Ok fellas. Alot of updating i have to do so i will start now!! So i went down to the boat on Saturday & Sunday. Had trouble getting to where my boat was because of this snow. So i am back at working on the boat. So what I have done for the past 2 days is proceed at diagnosing the engine for its low psi in cylinders 3 and 6 if you guys recall. So i put cylinders 3 and 6 at TDC by shoving a screwdriver in the spark plug hole until the screwdriver was jammed and i was told that is one way of doing it to make it easier for me. So i took the hose from the pressure gauge and took the valve out of there so i can get air going through. Then i connected the air compressor and adjusted it to 100psi to be blowing into it. So by listening carefully i heard air escaping from the inside of the manifold. I believe it was the manifold because i heard a hissing noise coming from there. SO as i understand that most likely the valves need to be adjusted particularly the exhaust valves. If im correct someone let me know. But that is it. Next time i go to the boat i will be taking the valve covers off and repeating the test. So this is it for now and if the weather does not get any worse i will be going to the boat more often will the advice you guys give me. So i will keep you guys more updated from now on. So than you guys for all your help and hopefully ill get the problem fixed!

 

[thumpar]

Re: Cylinders Low In PSI ? (HELP)

You need to make sure you are on the compression stoke while doing the test. This is a 4 stroke. Also, there are 2 manifold. Which one are you talking about?

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

You need to make sure you are on the compression stoke while doing the test. This is a 4 stroke. Also, there are 2 manifold. Which one are you talking about?

Both sides . And i thought that once your at DTC then you are on the compression stroke?

 

[thumpar]

Re: Cylinders Low In PSI ? (HELP)

Both sides . And i thought that once your at DTC then you are on the compression stroke?

TDC is on the compression stroke. Just because it is at the top of the stroke doesn't mean it is TDC. As you rotate the engine put your finger over the spark plug hole of the cylinder you want to test. When you feel pressure you are on the compression stroke.

 

[BigDog98]

Re: Cylinders Low In PSI ? (HELP)

TDC is on the compression stroke. Just because it is at the top of the stroke doesn't mean it is TDC. As you rotate the engine put your finger over the spark plug hole of the cylinder you want to test. When you feel pressure you are on the compression stroke.

Well for a fact I know that i was at TDC because the engine did not rotate at 100PSI pushing it. So at least i got that one right

 

[thumpar]

Re: Cylinders Low In PSI ? (HELP)

Well for a fact I know that i was at TDC because the engine did not rotate at 100PSI pushing it. So at least i got that one right

That doesn't prove anything. If you were on the exhaust/intake stroke it would not rotate. It would be more likely to rotate on the compression stoke. If you are going to take the valve covers off you would check to make sure they are both closed and then do the test.

 

[tpenfield]

Re: Cylinders Low In PSI ? (HELP)

Yea, from what you described, it is inconclusive . . . It does not sound like you used a leak test gauge, and you could be at TDC of the exhaust stroke rather than the compression stroke. The valves will be open on TDC of the exhaust stroke, whereas the valves will be closed at TDC of the compression stroke. So, you would hear hissing from the intake at TDC on the exhaust stroke.

If the valves were leaking it may be due to pitting of the valve seats or other issues, beyond a mere valve adjustment.

I would recommend doing a full leak test, with the proper gauge set, on all cylinders and see what it tells you.