overheating/boiling over/ engine noise/ no spark/ problems

[Patch]

Provoking thought thru experience and logic:

 

Here’s a question for U’s: What is the root cause of system pressures?

Resistance (R) right.

(R) : Compression is an example of resistance, viscosity, friction all factors of (R).

So now what if we consider causes and effects of (R)

That’s a simple question to answer right!

Here is a common one we see posted often: The Venture engine can run just fine on 3 jugs.

No it can’t! The fact that we are often unaware of dropping a Jug has to do with not the engine design rather the engine mountings; the effort to reduce vibration.

Those of us that have run the EU cars know firsthand the difference a bad hydraulic engine mount produces even on an engine that is firing or running correctly.

OK I am skipping over V angles and the inherent consequences.

Recently we had the opportunity to view a clip from Gregg across the Pond. Carl was the first to pick up on it and comment on likely not running on all 4.

So what did OP tell us about his running experiences on the stand or on the road? “overheats” his words so overheating and boiling over are not the same nor do they have the same consequences, also, not the same influences on the “duty” clocks!

The shake gave it away for me: How often do we see these engines run on three with no visible shake?

Yet in the clip shake is very obvious. Also obvious was the slapping noises picked up by the mike at some 6-8’ distance away. On the 2 MKII we ran even with downed Jugs, I needed a listening aid to hear the going ons so, it can’t be just 1 Jug for that engine right any more than it can be a simple overheating issue. This is opposites to the firing order of the crank or major crank imbalance is resulting from the pairing.

So at least 2 not firing: This is where we walk thru the (R) consequences to explain the chain reactions that we see and hear in the clip.

Starting with what OP told us and what he didn’t recognize but, first another question: Anyone thinks this bike would be able to accelerate at all in 5th and what about 4th?

There were likely 2 main issues, carbs and spark: This theory will apply even if the engine was running on 1.

Intake stroke draws fuel and air into a  jug whether it fires or not (that is just a matter of T. position and available supply), the piston reverses travel compresses without ignition, piston again reverses,  ex valve opens charge or charges are pumped into cold pipe down to collector / times down jugs plus evap plus flame from firing Jug exhaust and, we now have a 2000* constant because the cycles continue (make no mistake a warm pipe due to circulation will not ignite the fuel).

The attempt at driving speeds with some air flow over the system and the throttle now open more un burnt fuel puddles above the piston past the rings on compression strokes. Why “puddling” combustion temperatures not met and no ignition. But lots of O2 to fuel the fire below also pumped out.

Yet another 2 factors of (R) comes into play: Viscosity drops and so does pressure therefore the journals throughout are wet but not floating! Skipping past (coking) we also have increased slap throughout including thrust. Fuel past the rings reduce viscosity and therefore pressure but, increase friction more heat and again less viscosity. (duty cycle/life out the window)

Extreme duty: What’s included, seals, gaskets, friction surfaces including clutch and bearings, warpage, all perpetuating the extreme heat and is not reversible. Higher than limits of compression also can create high temp problems thru choked up port restrictions, as well as combustion issues.

Let’s add in a failed thermostat as a 3rd problem: (even tho there are bypasses to reduce risk of boiling over)

“Changed the stat and all is well bike runs great no more overheating problems” Again overheating and “boiling over” present different pictures and results.

OK I’d buy that peace of mind statement but would anyone with such experience believe it? What we can do is manage the results after the effects providing of course we correct the other issues.

Look what I found and who remembers Mopar’s stupidly late 60’s early 70’s ? How many blocks & heads did this trap burn hmm hmm

Anyone change a catalytic converter and not asked why it went prematurely? #1 cause after theft that is is fuel injectors leaking 2nd is burning oil. If we run a melted cat we fry that side of the engine, yet, most won’t check the fuel system for leaks because it is too expensive, weird or what?

 

Edited May 26, 2021 by Patch

[uncledj]

[Patch]

10 hours ago, uncledj said:

Well how about this: Just because some says a Yamaha Venture never...... (fill in the blank) an old bike is an old bike!

Old bikes need maintenance, maintenance performed a year ago regardless of how few miles between last maintenance then stored - the chemical fluids continue to degrade that in turn requires the maintenance to need repeating.

Examples hear seem clear, carbs, antifreeze, sticking issues excreta.

Ride the old bike more than storing it is better than the other way around.

Really not a conspiracy unclej just fact ;

[uncledj]

I would agree.   I was amazed a couple of months ago when I hit the starter button on my first gen and it started.

It's been sitting since 2015....Heavily dosed with Seafoam....same battery ...(on a maintenance charger)

Getting that old gal freshened up will be this Winters' project.  She's sitting in my pump shed, which is kept at at least 45 degrees and has a dehumidifier that pretty much runs all the time,  so I'm sure that helps.

One of these days I'm going to have the time to ride all these old bikes I have.

2006 Black Cherry RSV

1987 Venture Standard

1985 Honda Nighthawk 700S

1982 Honda CB900 Custom

1999 BMW Funduro GS650

1983 Yamaha TT600

1980 Honda CT110

I really got to clear out the stable.

[Marcarl]

1 hour ago, uncledj said:

I would agree.   I was amazed a couple of months ago when I hit the starter button on my first gen and it started.

It's been sitting since 2015....Heavily dosed with Seafoam....same battery ...(on a maintenance charger)

Getting that old gal freshened up will be this Winters' project.  She's sitting in my pump shed, which is kept at at least 45 degrees and has a dehumidifier that pretty much runs all the time,  so I'm sure that helps.

One of these days I'm going to have the time to ride all these old bikes I have.

2006 Black Cherry RSV

1987 Venture Standard

1985 Honda Nighthawk 700S

1982 Honda CB900 Custom

1999 BMW Funduro GS650

1983 Yamaha TT600

1980 Honda CT110

I really got to clear out the stable.

Yep

[uncledj]

But is it so wrong to love them all???   

[Patch]

There is a BUT tho unclej, a gen1 is not a fair example of good ownership. They run when they should be dead, a gen2 bike rider lets a bit of air out of the rubber when no ones looking just to keep in in eye sight. Lets face facts they are a bent attitude of a machine. I heard tell it takes an 1874 50-90 to lame dem mist-fits.

The thing is tho that stabilizers make a difference, draining the carbs when storing keeps the shell/casting ready to trigger  too.

You have enough bikes to know how to store them and likely prep them for a hard ride where as most rely on should be good?

[saddlebum]

12 hours ago, Patch said:

 most rely on should be good?

Whats wrong with that ain't that right up there with if it ain't broke don't fix it.

[Patch]

One of the learning curves I went thru was when Ajay came of age and showed interest in mechanics. That's when I began collecting bike projects again. Also tho and more importantly for myself was the MB cars I took a liking to. As I ventured into the drive trains the tolerances were so different then what I had been accustom to. 

When we think of the rotation speeds of the cranks, cams and chains that are built now V the early racing years we grow a whole lot of respect for maintaining oil pressures.

Suzuki on the other hand and in my experience is a looser engine then Yamaha. But and that said Yam has to rely more on viscosity being consistent. I think it was 2010 Yam had a 1000?? that developed a thrust issue that showed up around 14k klm's. One has to question why the mileage for this catastrophic fail was so consistent?

Viscosity is the difference between 2 friction surfaces and in the case journals. The most critical is at the maximum bottom before reversing direction or stroke. This is when the connecting rod is about to hit its greatest angle. Any lose of thrust tolerance will cause the journals to canter. That in turn loads the connecting pin, that increases slap, wear on the skirts, wear on the pin bosses, oval bores...... In the case of the Yam sport bike it cause the balance shaft to collide with the crank, blow the bottom end out. Yam did come up with a fix for it but the customers weren't notified (best of my recollection)

So the point is if you overheat the engine do we recommend after addressing the overheating issue "and change the oil"? 9 out of 10 times they'll answer I just changed it before it overheated, its good!

Unclej mentioned seafoam, personally I put it in my engines before storing, in the crankcase, anything from my diesels to the bikes. It does not effect the friction plates, it is not a friction modifier, it is only a mild cleaning agent, it primary purpose is to liquefy . On a Venture we already know that they tend to clot at the filter feed.  

If it aint broke don't fix it, aint preventative maintenance ;     Agreed?

Edited May 29, 2021 by Patch

[saddlebum]

15 minutes ago, Patch said:

If it aint broke don't fix it, aint preventative maintenance ;     Agreed?

Never said it was

Its just a handy excuse for a guy like me who spends 10 plus hours a day fixing trucks and the last thing I want to see when I get home is another wrench. This winter since I have been off work due to covid It has received a lot of attention though.

[larrydr]

I like going a dealer or another bike repair shop and guys tell me that they have some junkers out back in the storage shed and I say great ...Are they for sale ?? ..They then say yes , but why would you want them  ... I like nothing better buying one and 2 weeks ride it  back to shop I bought the bike form saying I have a used bike for sale that runs great ...I have often found that some little problem which does not come to any one of the guys mind is all that is wrong ...I just bought one last week and all that was wrong was the crankcase vent was plugged and the engine was pushing the oil out in about 30 minutes of run time ..Another they said was disaster and that it needed new carbs ...All there was wrong was the carb floats were  jammed against the float bowel 

[Patch]

When I started monkeying around as a kid some couple years back the bone yards were great place to go. One day I crawled into a container of carb castings, been hook ever since.

"pushing the oil out in about 30 minutes of run time "    I'd likely check for stuck rings as well as clearing the ventilation. We have a thread on that stuck rings.

Wanted to share these 2 videos with U's, tho not bike engines they show pin boss damage as well as oil cooling short comings. In one video (going by memory) the mechanic pushes down on a piston that then drops. Usually we expect to see some impact scares from knocking the combustion chamber. In the other it shows more the effects of oil cooling results due to poor design oil jets. The oil jets have me thinking about nozzle or tip design. So a question for Ben: on the big diesels whats the most common piston and pin setup you see? And what pressures are they usually?

https://youtu.be/MsAa1DwLpKQ 

https://youtu.be/ihYulB1mzhE