Engine Blow By?

[sje0123]

Re: Engine Blow By?

Just out of curiosity, you bought a boat w/o a sea trial or having someone look it over? Was it a good deal? What was the reason you were having it "timed"?

Sounds to me like you are being overly worried. Take it out, run it and see how the day goes. Have someone available to tow you back just in case. Or as stated, leave it hooked to the tow vehicle at the ramp and see how it does under moderate load.

 

[jmw129]

Re: Engine Blow By?

Just out of curiosity, you bought a boat w/o a sea trial or having someone look it over? Was it a good deal? What was the reason you were having it "timed"?

Sounds to me like you are being overly worried. Take it out, run it and see how the day goes. Have someone available to tow you back just in case. Or as stated, leave it hooked to the tow vehicle at the ramp and see how it does under moderate load.

You're right, I didn't run or take it out on the water before buying. I paid $700 for the boat but the sundeck & bench seating needs replaced to it needs some interior work done.

I trusted the seller. I have bought 2 boats in the past and both sellers were honest and this seller seemed like he was honest.

He told me that he had bought the boat as a project and didn't get to finish it because he claims his wife doesen't like boating and was giving him a hard time about having the boat and was pressuring him to sell.

He also told me that he cleaned the carbs, replaced all the gaskets, plugs, and oil. When I started the boat at my house, the idle was very high and sounded like it needed to be adjusted.

So I took it in to have it looked over by my mechanic and that is when I received the info from him statng that I had blow by indicating weak rings. He didn't charge for the timing of the engine, just winterized.

My mechanic never made any comments to me about blow by with my 2 boats prior so that really worried the you know what out of me. I felt like I may have been taken by the seller.

 

[dan t.]

Re: Engine Blow By?

You paid $700 for the boat, it runs, it floats what more do you expect for that kind of money.

 

[jmw129]

Re: Engine Blow By?

Yeah I didn't pay much for the boat but at this time of year, you can find quite a few older boats out there in the $700-$1,000 that are mechanically in great shape just older such as 1980 to 1987 is typically the year range.

My 2 other boats were $1,000 or less so maybe I'm darn lucky or the king of deals, or maybe a mix of boat. I don't believe in boat payments.. I know, I guess I'm due for some extra repairs as you get what you pay for right?

 

[dollarten]

Re: Engine Blow By?

The small tube that is located on top of the valve cover does not have the rubber tube connected to the air filter / housing around the carb. So with this tube not being connected, I did see a small amount out on a almost regular basis / consistent basis coming out of this tube while running in idle is what I seen when my mechanic timed the engine before winterizing the engine. Wasn't a huge amount coming out but I have been told that when you up'd the RPM's you would then see the blow by with alot more smoke coming out?

Is that an accurate statement?

z This out could find out with the boat backed into the water . You could see any increase , if any . Unless there is oil dripping out of the silencer when the engine is not running , I would see a non issue here Also if the blow by is excessive the air silencer will not pick it all up when underway

 

[bnicov]

Re: Engine Blow By?

You bought a boat that needs work for 700 bucks. That it runs at all is great. Do your work to the deck and interior and run it next year, I'll bet that motor still has a few years in it. Engines run with blow by for a long time before they finally quit. Keep it tuned and keep an eye on the oil level and have fun with her.

 

[gus-gus]

Re: Engine Blow By?

Yeah I didn't pay much for the boat but at this time of year, you can find quite a few older boats out there in the $700-$1,000 that are mechanically in great shape just older such as 1980 to 1987 is typically the year range.

My 2 other boats were $1,000 or less so maybe I'm darn lucky or the king of deals, or maybe a mix of boat. I don't believe in boat payments.. I know, I guess I'm due for some extra repairs as you get what you pay for right?

The one real possibility is both sides are somewhat correct. If an engine which has sat for extended periods experiences excessive blowby and still has pretty fair compression, It may be as simple as unseated rings.
It is common with aircraft recip engines that have experienced extended storage times or periods of no use, will cause low compression.
The fix is "run it" The engine could come back with a few hours of use. Give it a try. The fuel pump running backwards? Riiiight ! You do realize with a diagnose like that, You are only enabling his drug use by paying your bill.

Where are you? Your profile is lacking your location, so no one will know if your next door or not.

 

[jmw129]

Re: Engine Blow By?

The one real possibility is both sides are somewhat correct. If an engine which has sat for extended periods experiences excessive blowby and still has pretty fair compression, It may be as simple as unseated rings.
It is common with aircraft recip engines that have experienced extended storage times or periods of no use, will cause low compression.
The fix is "run it" The engine could come back with a few hours of use. Give it a try. The fuel pump running backwards? Riiiight ! You do realize with a diagnose like that, You are only enabling his drug use by paying your bill.

Where are you? Your profile is lacking your location, so no one will know if your next door or not.

lol.. the drug use comment was funny. Much appreciated! I live in the midwest not far from the Mississippi. So I do a majority of my boating on the Mississippi which is a horrible river to break down on. It's big and very loooong! Oh did I mention a lot deeper than what people realize!

So what you're saying is even with a compression reading of 125 per cylinder or close to it, the engine even though it's old could still in fact be hitting realistically 80% to 90% of it's adverstised HP with small amount of blow by?

 

[jmw129]

Re: Engine Blow By?

The one real possibility is both sides are somewhat correct. If an engine which has sat for extended periods experiences excessive blowby and still has pretty fair compression, It may be as simple as unseated rings.
It is common with aircraft recip engines that have experienced extended storage times or periods of no use, will cause low compression.
The fix is "run it" The engine could come back with a few hours of use. Give it a try. The fuel pump running backwards? Riiiight ! You do realize with a diagnose like that, You are only enabling his drug use by paying your bill.

Where are you? Your profile is lacking your location, so no one will know if your next door or not.

Please explain what you mean by "Unseated rings"? Do you mean rings that just need movement to re-align to their original position?

 

[gus-gus]

Re: Engine Blow By?

Please explain what you mean by "Unseated rings"? Do you mean rings that just need movement to re-align to their original position?

When rings seat in, they wear to fit to the roundness or in must cases the out of roundness of a cylinder and the land or edge of the piston ring groove. When engines sit the rings and cylinder expand and contract at different rates , because they are such different metals and simply (I don't understand the physics) either stick in the ring groove and aren't free enough to follow the cylinder wall or are held tightly against the cylinder wall on one side forcing the piston over, unseating the rest of the rings. I have been watching this phenomenon for 36 years and have seen many spend thousands fixing a situation which sitting unused has caused. I have seen it with 2 strokes and air cooled engines the most, however I have believed it was the trouble with a few automobile engines I have dealt with.
I hope this explains it. I am far from an expert, yet I have brought engines back many times by using them

 

[jmw129]

Re: Engine Blow By?

When rings seat in, they wear to fit to the roundness or in must cases the out of roundness of a cylinder and the land or edge of the piston ring groove. When engines sit the rings and cylinder expand and contract at different rates , because they are such different metals and simply (I don't understand the physics) either stick in the ring groove and aren't free enough to follow the cylinder wall or are held tightly against the cylinder wall on one side forcing the piston over, unseating the rest of the rings. I have been watching this phenomenon for 36 years and have seen many spend thousands fixing a situation which sitting unused has caused. I have seen it with 2 strokes and air cooled engines the most, however I have believed it was the trouble with a few automobile engines I have dealt with.
I hope this explains it. I am far from an expert, yet I have brought engines back many times by using them

Thank you for the helpful input but I have another question for you..

Now is there a special type of oil additive such as Rislone that would help with the un-seated rings to properly re-seat or reduce the wear or tear on the engine when being ran after sitting for a long period of time??

 

[sschefer]

Re: Engine Blow By?

Unseated rings are caused when an engine sits for a prolonged period of time and the fuel and oil in the cylinder turn to sludge. If the cylinders are properly prepared with a product like Marvel Mystery Oil or Sea Foam followed by turning over by hand and then a full oil change the sludge should break down and wash out. If it doesn't, when the engine is started there is a strong possibility that there will be flame over the edge of the piston that will carbonize the sludge and permanently stick the ring in the land. In older, worn engines, the pistons can become eggshapped and the cylinders tappered. If the rings can't move then there is no way to create the seal that was once achievable.

Worn valve guides can produced many symptoms but the most common is a noticable puff of blue smoke after the engine has sat for a short period of time. There is no doubt that blow by can be a sign of badly worn valve guides but I think in this case it's more likely that you've stuck a few rings. My first suggestion would be to drain the oil, pull the plugs and pour Sea Foam into the cylinders and let it sit for a couple of days. With the plugs still out, turn the engine over by hand over to get most of the Sea Foam out then fill them wil Marvel Mystery Oil and let that sit for a couple of days and repeat turning the engine over by hand. Once you think that most of the oil is out of the cylinders, drain the debrie out of the oil pan, change the oil filter and add fresh oil. You can now put the plugs back in and crank the engine with the start but disconnect the coil wire or ignition system so the engine will crank over but won't start. This will dilute any of the remaining additive with fresh oil and give sufficient lubricant for running the engine.

Finally, put in a fresh set of plugs, reconnect the coil wire or ignition system and start the engine. About 50% of the time this works to unstick the rings and if it is stuck rings the blow-by problem should dissappear within the first hour of running.

There's no guarantee that this will work but it's the least expensive thing you can do and it will not further damage your engine.

 

[jmw129]

Re: Engine Blow By?

Unseated rings are caused when an engine sits for a prolonged period of time and the fuel and oil in the cylinder turn to sludge. If the cylinders are properly prepared with a product like Marvel Mystery Oil or Sea Foam followed by turning over by hand and then a full oil change the sludge should break down and wash out. If it doesn't, when the engine is started there is a strong possibility that there will be flame over the edge of the piston that will carbonize the sludge and permanently stick the ring in the land. In older, worn engines, the pistons can become eggshapped and the cylinders tappered. If the rings can't move then there is no way to create the seal that was once achievable.

Worn valve guides can produced many symptoms but the most common is a noticable puff of blue smoke after the engine has sat for a short period of time. There is no doubt that blow by can be a sign of badly worn valve guides but I think in this case it's more likely that you've stuck a few rings. My first suggestion would be to drain the oil, pull the plugs and pour Sea Foam into the cylinders and let it sit for a couple of days. With the plugs still out, turn the engine over by hand over to get most of the Sea Foam out then fill them wil Marvel Mystery Oil and let that sit for a couple of days and repeat turning the engine over by hand. Once you think that most of the oil is out of the cylinders, drain the debrie out of the oil pan, change the oil filter and add fresh oil. You can now put the plugs back in and crank the engine with the start but disconnect the coil wire or ignition system so the engine will crank over but won't start. This will dilute any of the remaining additive with fresh oil and give sufficient lubricant for running the engine.

Finally, put in a fresh set of plugs, reconnect the coil wire or ignition system and start the engine. About 50% of the time this works to unstick the rings and if it is stuck rings the blow-by problem should dissappear within the first hour of running.

There's no guarantee that this will work but it's the least expensive thing you can do and it will not further damage your engine.

Steve... What you said make's complete sense. Thank you for the very much appreciated advice!

 

[jmw129]

Re: Engine Blow By?

Like to say Thank You to everyone who has posted good advice, experiences, solutions, and so on. Much appreciated everyone!!

 

[gus-gus]

Re: Engine Blow By?

Thank you for the helpful input but I have another question for you..

Now is there a special type of oil additive such as Rislone that would help with the un-seated rings to properly re-seat or reduce the wear or tear on the engine when being ran after sitting for a long period of time??

Unseated rings are caused when an engine sits for a prolonged period of time and the fuel and oil in the cylinder turn to sludge. If the cylinders are properly prepared with a product like Marvel Mystery Oil or Sea Foam followed by turning over by hand and then a full oil change the sludge should break down and wash out. If it doesn't, when the engine is started there is a strong possibility that there will be flame over the edge of the piston that will carbonize the sludge and permanently stick the ring in the land. In older, worn engines, the pistons can become eggshapped and the cylinders tappered. If the rings can't move then there is no way to create the seal that was once achievable.

Worn valve guides can produced many symptoms but the most common is a noticable puff of blue smoke after the engine has sat for a short period of time. There is no doubt that blow by can be a sign of badly worn valve guides but I think in this case it's more likely that you've stuck a few rings. My first suggestion would be to drain the oil, pull the plugs and pour Sea Foam into the cylinders and let it sit for a couple of days. With the plugs still out, turn the engine over by hand over to get most of the Sea Foam out then fill them wil Marvel Mystery Oil and let that sit for a couple of days and repeat turning the engine over by hand. Once you think that most of the oil is out of the cylinders, drain the debrie out of the oil pan, change the oil filter and add fresh oil. You can now put the plugs back in and crank the engine with the start but disconnect the coil wire or ignition system so the engine will crank over but won't start. This will dilute any of the remaining additive with fresh oil and give sufficient lubricant for running the engine.

Finally, put in a fresh set of plugs, reconnect the coil wire or ignition system and start the engine. About 50% of the time this works to unstick the rings and if it is stuck rings the blow-by problem should dissappear within the first hour of running.

There's no guarantee that this will work but it's the least expensive thing you can do and it will not further damage your engine.

Excellent sschefer, The physics makes perfect sense. I/we never spent an extra moment oiling, foaming or softening the carbon. It makes sense to do so, but even without doing that I have a 80 or 90% success rate with engines.
I would just run it. I know me. The soften and fuss with it would never happen. LOL.

I used Rislone, two times and each time (aircraft) we had a bearing failure shortly after. The issue as we understood it was the loose carbon broke loose and even in microscopic amounts, it found it's way to bearing surfaces and joined hands to score crank and cam shafts. I don't trust that stuff.

 

[sschefer]

Re: Engine Blow By?

Excellent sschefer, The physics makes perfect sense. I/we never spent an extra moment oiling, foaming or softening the carbon. It makes sense to do so, but even without doing that I have a 80 or 90% success rate with engines.
I would just run it. I know me. The soften and fuss with it would never happen. LOL.

I used Rislone, two times and each time (aircraft) we had a bearing failure shortly after. The issue as we understood it was the loose carbon broke loose and even in microscopic amounts, it found it's way to bearing surfaces and joined hands to score crank and cam shafts. I don't trust that stuff.

Agree, I can see where that would be a big problem when you use it in an engine that has roller bearings. At best, in this case it's 50/50 since the motor has been run and the carbonization of the ring lands has likely already occured. I think it would be worth a shot though.

 

[jmw129]

Re: Engine Blow By?

Excellent sschefer, The physics makes perfect sense. I/we never spent an extra moment oiling, foaming or softening the carbon. It makes sense to do so, but even without doing that I have a 80 or 90% success rate with engines.
I would just run it. I know me. The soften and fuss with it would never happen. LOL.

I used Rislone, two times and each time (aircraft) we had a bearing failure shortly after. The issue as we understood it was the loose carbon broke loose and even in microscopic amounts, it found it's way to bearing surfaces and joined hands to score crank and cam shafts. I don't trust that stuff.

So when you just run the engine do you use fuel cleaners? or crankcase cleaners such as Seafoam?

Seafoam is a water like liquid while the Rislone is almost regular oil.

 

[gus-gus]

Re: Engine Blow By?

So when you just run the engine do you use fuel cleaners? or crankcase cleaners such as Seafoam?

Seafoam is a water like liquid while the Rislone is almost regular oil.

I must admit I am fairly new to Seafoam. I was advised to use it in an motorcycle engine I have. It has 6 carbs, but it was interesting since nothing in Seafoam is going to reverse the effects of Ethanol, so it seemed like a waste of money and time.
So to answer your question, it would be not really.
Regular and often oil changes seem to be the best action for 4 stroke power sections, as far as I am concerned and occasional fuel system cleaner seems to correct most of the poor fuel system performance issues for me. Being new to boat motors, I stand with my ears open to hear as much as possible, just like you.
The internet is sure an awesome place.

 

[sschefer]

Re: Engine Blow By?

I must admit I am fairly new to Seafoam. I was advised to use it in an motorcycle engine I have. It has 6 carbs, but it was interesting since nothing in Seafoam is going to reverse the effects of Ethanol, so it seemed like a waste of money and time.
So to answer your question, it would be not really.
Regular and often oil changes seem to be the best action for 4 stroke power sections, as far as I am concerned and occasional fuel system cleaner seems to correct most of the poor fuel system performance issues for me. Being new to boat motors, I stand with my ears open to hear as much as possible, just like you.
The internet is sure an awesome place.

Sea Foam is another one of those products that sort of falls into that ... does it really work categories. The answer, sort of.. I've soaked carboned up pistons in it and had mixed results but it's actually supposed to be used in a running engine so it's not as effect when just soaking. I think the Quicksilver products are just as good in a running engine.

Sea Foam has been around a lot longer than Ethanol so in that regard I'd have to say no, it's not going to do much for you. I would rather trust Marine StaBil for Ethanol for that purpose and I do.

What Sea Foam seems to do best is ub decarbonizing a running motor. When mixed with fuel, heated and pressurized in a cylinder it is effective at breaking down the carbon buildup on piston tops and ring lands.

Rislone and Marvel Mystery Oil are the two best products I've found for trying to prep a motor that's been sitting for a long time. Truely, the best method is to tear it down and go through it but if that is not possible then sometimes, and I do mean sometimes, the use of either of these products might do the job.

There are times when you don't want to use it such as oil bath motors with roller bearings. As was mentioned in a prior post, the debri that is broken loose could damage the bearing surfaces since it will not be filter out prior to running.

 

[jmw129]

Re: Engine Blow By?

The debri breaking and being pushed through oil or with the oil vs. being burned up or to a small amount that isn't harmful is my concern. I've used seafoam in the past and have had a 75% or better sucess rate at feeling, hearing, and seeing the engine in better running condition. Seems like the liquid is thin enough to move around when needed.

Now the Rislone I haven't used yet for engine treatment and after reading about the bearings being spun on 2 aircraft engines really does concern me.

I'm sure in auto application the Rislone engine treatment probably does a great job cleaning the heads & rings but considering it's a marine engine at much higher RPM's I have a feeling it wasn't designed for the marine application.

At least with Seafoam it says right on the bottle that it can & is designed to put into a Marine engine which makes me feel alot better.

My Dad swears by Seafoam and I can see how a strong cleaner could clean out the inside of an engine or at least reduce it which is a win either way in my eyes.

The seafoam made a big difference on my snowblower last winter.