78 XS750 with excessive oil burning and lower compression in center cyl.

[jefferson997]

If I read that right, you're at 4oz per 200 miles, which is 20oz in a 1000, or 1,600mi / qt. This is rate of consumption rarely, if ever, gets resolved by piston soaks or sump additives. I think this bike needs to have the engine opened to service the piston and liners. Typically, if you are at or over ~150hr/qt, methods and products like this have their best chance.

The Audis that the B-12 was used on were using way more oil than that and the B-12 resolved the issue. I didn't pay real close attention to how much oil was being used, but on a 300 mile ride I could easily add 1/2 qt. when I got back so what it's using now is quite a bit less after the B-12 soak. Im going to get the cylinders level and do another soak cycle with the B-12 and see what happens. Since this last oil top off was so much less than the first ride, I'm wondering if the soak loosened some stuff up and riding is working it out of the rings so there is less oil being used with miles and time. Also going to borrow the compression tester from my brother and see where it's at now. Maybe I can find those readings from back when.

 

[jefferson997]

I still have never seen the pictures I posted. Can anyone tell me if they are there or not?

Reading some other threads and noticed no pictures work for me. Is there some trick?

 

[Overfill]

The Audis that the B-12 was used on were using way more oil than that and the B-12 resolved the issue. I didn't pay real close attention to how much oil was being used, but on a 300 mile ride I could easily add 1/2 qt. when I got back so what it's using now is quite a bit less after the B-12 soak. Im going to get the cylinders level and do another soak cycle with the B-12 and see what happens. Since this last oil top off was so much less than the first ride, I'm wondering if the soak loosened some stuff up and riding is working it out of the rings so there is less oil being used with miles and time. Also going to borrow the compression tester from my brother and see where it's at now. Maybe I can find those readings from back when.

Hopefully your bike goes against the norm like those Audis, then. Regardless--most of the time B-12 piston soaks decrease the consumption rate, and that's always a good thing.

 

[Bonz]

It's not wrong in saying all of us would like a silver bullet. But excessive oil consumption can only be mitigated so much. It's good experience in what is becoming a lost art to take the top end off an engine, lightly crosshatch, and re-ring it with a couple size overs and get on down the road.

I've had my ZRX1200 (10:1 stock CR) apart a couple of times going with new pistons and rings, and you'll learn a lot. First time was to install ZZR1200 pistons and remove the base gasket (11.0:1), then decided to go all the way to install JE 12.5 to 1 pistons.

 

[Pete in PA]

There is no doubt that doing a top end is the best for the bike and adding to your experience.
I for one will exhaust all other options first.
I saw the Audi B12 videos. It worked. Any bikes or cars that sat will gum up the rings. E10 gas also does it with just over winter storage.

 

[Nessism1]

E10 won't stick rings over winter storage. I live in CA, which has used E10 for a long time now, and none of my motorcycles or lawn equipment have issues. In the past, my motorcycles would plug a pilot jet or two, before running fuel stabilizer, but never stuck a ring.

 

[Pete in PA]

There have been more than a few instances of ST1300's on the forum of not starting. Ethanol build up on the valves that hold them open just enough so they don't start.
Stuff forms a goo likened to apple pie filling cooked on the bottom of an oven.

Follows a long road trip, then stored a few months.

How long could you winter a bike in Cali???

 

[dnewton3]

There have been more than a few instances of ST1300's on the forum of not starting. Ethanol build up on the valves that hold them open just enough so they don't start.
Stuff forms a goo likened to apple pie filling cooked on the bottom of an oven.

Huh? Can you expound on this ... I find it hard to believe.
- why ST1300s? (if it can happen to them, why not all engines? and if it happened to all engines, we'd hear a lot more about it)
- what is it EXACTLY that builds up this "goo" that builds up on the valves?
- how does the "goo" get on the valves? (these are fuel injected engines, so when you shut off the engine, it should not be getting any more fuel, so there should be no excess fuel to "goo")


Ethanol is not a great thing for long-term storage; I agree. But I think at times the effects are greatly exaggerated in an effort to blame all manner of failure modes when the root cause is unknown or not understood.

 

[Rand]

I still have never seen the pictures I posted. Can anyone tell me if they are there or not?

Reading some other threads and noticed no pictures work for me. Is there some trick?

Try another web browser if you are using something old the forum was upgraded to WEBP images.
You could download OPERA, CHROME firefox etc. The pictures view fine for me.

Also you could try using actual HPL oil (not the cleaner)
Which cleans more than the HPL cleaner that is designed for transition to HPL oil.

 

[Bonz]

Huh? Can you expound on this ... I find it hard to believe.
- why ST1300s? (if it can happen to them, why not all engines? and if it happened to all engines, we'd hear a lot more about it)
- what is it EXACTLY that builds up this "goo" that builds up on the valves?
- how does the "goo" get on the valves? (these are fuel injected engines, so when you shut off the engine, it should not be getting any more fuel, so there should be no excess fuel to "goo")


Ethanol is not a great thing for long-term storage; I agree. But I think at times the effects are greatly exaggerated in an effort to blame all manner of failure modes when the root cause is unknown or not understood.

Carburetors have been gumming up since the dawn of internal combustion. Ethanol gives us something to talk about. Yes it's more finicky, but there are known methods to deal with it. Fuel injection makes it less so to a very high degree, especially "gumming on the valves" which makes no sense.

I had an ST1300 for a while years ago. I cannot say that's accurate.

 

[KrisZ]

The "ethanol" boogeyman strikes yet again.

 

[Pete in PA]

I had an ST1300 couple bikes back. Didn't happen to me but it's a fact. Happened to more than a few people. Do a search on the forum.

 

[Bonz]

I was on the ST1300 forum as an owner and spent considerable time there as the point in working with members and Delkevic to introduce slip-ons. I missed something as I never saw this issue mentioned.

I gather analysis was done and it was congealed ethanol? Not wanting to get on the wrong side of this discussion and be argumentative, I am simply curious by posing the contrary to help flesh out a concrete cause.

Really trying to visualize the physical manifestation in a bike with fuel injection. Where excessive fuel puddles on the backside of partially closed/open intake valves, ethanol congeals because it apparently evaporates slowly in an engine that is fully warm (typically, from information shared) after a long ride and keeps valves from shutting so the bike won't start the next time.

I would expect they would know exactly where the malfunction is with the fuel system component as fuel has been specifically identified as the culprit.

 

[Pete in PA]

Here's one reference to it with a quick search. The forum has lost a lot with a few "resets".
Ethanol IS the boogeyman. Dont ever think that it's great, or causes no problems. It's an excuse and joke shoved on us by the government.

 

[Bonz]

There have been more than a few instances of ST1300's on the forum of not starting. Ethanol build up on the valves that hold them open just enough so they don't start.
Stuff forms a goo likened to apple pie filling cooked on the bottom of an oven.

Follows a long road trip, then stored a few months.

How long could you winter a bike in Cali???

I understood this to mean gas behind the valves (between valve and seat) gummed and kept them from closing.

Here's one reference to it with a quick search. The forum has lost a lot with a few "resets".
Ethanol IS the boogeyman. Dont ever think that it's great, or causes no problems. It's an excuse and joke shoved on us by the government.

View attachment 244988

This mentions valve guides. Is it a ring that forms around the valve stem and therefore the valve can't travel in the guide?

Either way, apparently the valve springs aren't strong enough to overcome a resistance that other engines using ethanol are exposed to as well. Really interesting.

 

[Bonz]

Thinking of valve spring tension, are bikes that experience this higher mile bikes? That's one thought. Another thought is with the relatively low redline, Honda in typical fashion, may have used the least valve spring tension needed.

Can anyone add as to why this may happen after longer rides and then the bike sits? The bike doesn't know if it's been 600 or 60 miles. Once the engine is up to temperature and oil up to temperature, it's all the same when the bike stops and cools.

 

[dnewton3]

I understood this to mean gas behind the valves (between valve and seat) gummed and kept them from closing.

As did I, Bonz ...
I'm going to dissect his assertions; no reflections on your take on this, Bonz.


These are fuel injected bikes he's referring to. There is very little chance excess fuel is getting to the valve seats upon shutdown. Why? Because when you shut the bike off, the fuel injection ceases IMMEDIATELY, but the engine will run a few revolutions as it coasts to a stop. For humans, it's imperceptible to hear, but no engine just STOPS turning over when the key is shut off. The engine crankshaft will turn a few turns after the fuel and ignition are shut down because of the mass of the rotating bottom end assembly. Hence, any fuel vapor in the intake track continues to be moved out of the system as the engine finishes a few turns with NO FUEL BEING INDUCED from the injectors. So, I say this claim of ethanol causing stuck valves in this scenario is total hogwash. It's some lame attempt to blame fuel when something else is afoot.

This mentions valve guides. Is it a ring that forms around the valve stem and therefore the valve can't travel in the guide?

How is it EXACTLY that fuel would get on the topside of the head anyway? If you're getting raw fuel on the valve stem, then you've got mucho big problems ! Again - blaming fuel for something that shouldn't be taking place in a normally operating engine. Regardless if it's pure gas or E10 gas, it should NOT be getting to the valve stem seal. And if it is, there's a really big problem going on. And it should be readily apparent; it would reek of fuel in the oil and it would also show up as fuel dilution in a UOA. And in fact, gasoline is a solvent of sorts when it's in oil; it dilutes the oil. So just how is it that the valve stem is sticking to the valve if fuel dilution is present at the seal?????????? Some people just want to find evil in everything ethanol touches, and they don't think very far into their excuse of what they claim.

Either way, apparently the valve springs aren't strong enough to overcome a resistance that other engines using ethanol are exposed to as well. Really interesting.

I cannot speak to this. But it's a possible explanation. But if this were in fact the root cause, then how is that the fault of fuel??? The weak springs can't close the valve; must be the fuel's fault. Really ???? How about we just say if the springs are weak, it's either a design or manufacturing defect?


Again - I agree that ethanol isn't a desirable thing in gas. I don't like it, in general. But I also don't believe all these made up, bovine manure stories which blame fuels for things which reasonably cannot happen.



FACT: all normal gasoline products will eventually gum up if left long enough. Even 100% "pure gas" will gum up in a carb, if you leave it there for a year or longer. Removing ethanol from gasoline improves its shelf life, but it does NOT make gasoline have an infinite life. Gas is volatile; it's gonna gum up eventually no matter if it has ethanol in it or not. It just happens sooner when ethanol is present. The greatest risk with ethanol is that it's hygroscopic; it attracts moisture, and that presents different problems.


So far, all I've seen from his claim is conjecture and a snippet from a website which clearly has no real analytical basis; it's just some shade tree mechanic's attempt to blame something he's not even thought through. I find it implausible that ST1300s get stuck valves because of ethanol in fuel; no real, credible evidence has been put forth as proof.

I remain skeptical.

 

[Bonz]

I can't make mechanical sense of it either. Pete in PA isn't a bad guy here, he's taking the discussion where it was going and I appreciate the new puzzle to figure out, and with a particular bike I had.

To be clear, not saying the valve springs are "weak". To me, it begs to ask if they could be part of this equation though. Whatever is happening, the valve springs aren't closing the valves on start up after sitting as stated in the shared excerpt, and that's where my mind went.

Pete in PA- has someone verified visually the culprit as an "apple pie like filling" keeping valves from closing (back of valves or valve stems) as was shared earlier? That would narrow the scope quite a bit.

 

[jefferson997]

Surprised to find more posts. Evidently not getting notification. As an update, I took a 400 mile trip last week. 200 miles down with a day break and then 200 miles back. Ran 75 to 80 both ways. Checked the oil after going down and it was still full and I was pleasantly pleased. The oil check after I got back was below the add line and took right at 3/4 of a qt. Have no clue as to the inconsistency of oil usage unless the oil cooler drained down the first time and didn't the second. Nothing is making sense.

 

[Bonz]

What are your spark plugs looking like after the ride you just took? As well, are you checking on the center stand or on level ground? I'm going to assume when checking the oil, the bike position is consistent. Check it a few more times at different places on the ride, etc. That will hopefully help discern if there's oil caught up in the cooler.

Was the ride consistent with respect to throttle use both ways? Maybe more throttle one direction, less load and more engine braking the other direction? Just spitballing here.