Time for me to address the 800lb Gorilla in the room.(Engine knock thread) REVIVED!

[mcgovern61]

If it's out of the frame it's a good time to remove the pulse generator housing and clean up the mechanical advance underneath it, spray it good with brake cleaner then some wd-40 then lightly grease I used 3 in 1 oil on all moving parts the thing is you need to check and see if it's rusty or not moving freely back and forth..it's a simple process, lube and put back your vacuum advance or pulse generator housing,, good luck sir.. :grin:

I do have the pulse generator housing off and it is real clean inside and everything moves freely.

 

[danf]

If it's out of the frame it's a good time to remove the pulse generator housing and clean up the mechanical advance underneath it, spray it good with brake cleaner then some wd-40 then lightly grease I used 3 in 1 oil on all moving parts the thing is you need to check and see if it's rusty or not moving freely back and forth..it's a simple process, lube and put back your vacuum advance or pulse generator housing,, good luck sir.. :grin:

I do have the pulse generator housing off and it is real clean inside and everything moves freely.

It's clean inside of the vacuum advance plates and behind on the housing or are you talking about the mechanical advance under it all still on the engine.. That's what I'm talking about..

 

[mcgovern61]

I was talking to a good friend of mine in Florida that does hot rod work and also works as a professional diesel engineer. I asked him about the exhaust valves being whitish and the pipes bluing and he basically said the same thing here. :music:

However, he went on to ask a few questions and asked if the bike had any vacuum leaks??? I said no (not that I remember??) He explained that he had an engine with similar problems (heistation, white exhaust valves, hot exhaust pipes) and knew that the carb mix should have been OK, timing was OK and everything else should have been OK. he went to take the carb off and found a single hairline crack that was causing enough of a vacuum leak to make the engine run leaner than it should otherwise. Once again he asked if there was any possiblility of a vacuum leak??

I had to think about that and then I realized something that caught my eye when I first got the bike. There was smoke in the garage after a startup and I remembered some of the smoke getting sucked in at the intakes! (This was at 2000 RPM during warm up) I also remember pulling the carbs off several times and not replacing the o-rings on the intake to heads, just re-using them with a little vasoline to buy me some time and then not replacing them. #3 hissed at one point and I tightened down on all of them, but maybe they still had some leaks. :swoon: :rtfm: :whip: :blush: :doh:

This lead to an overhead cam conversation and timing and he asked about the condition of the springs! I explained that #3 intake was easy to compress. He said they probably all need to be replaced and to be careful on an overhead cam engine, "THE VALVES CAN FLOAT REAL EASY IF THE SPRINGS ARE WORN EVEN A LITTLE." Further he said, (and I quote) "IF THE SPRINGS ARE WEAK AND THE VALVES START TO FLOAT, YOUR CAMS WILL WEAR UNEVENLY AND YOU WILL GET WHAT SOUNDS LIKE A KNOCK AT THE ROCKERS"! :salute:

 

[danf]

Most awesome info...I usually burn some sage by the intake to see if the smoke get's sucked in or not anywhere... Cool..

 

[scdmarx]

Of course! The vacuum leak! :doh:

We have a smoke machine at work. It heats up an oil solution (like baby oil?) and connects to the car battery for power. It blows smoke out of the end of a hose that you can attatch to a vacuum port, or where ever you need. It's only capable of pressurizing about 2PSI, but that's enough with the car in the shop and the doors closed, with a flashlight you can see any place where the smoke comes out. I use it to find leaks at intake manifolds, gaskets, hoses, I even find leaking gas tank seals with it.

I like what he said about the weak springs wearing the cams. That makes sense. But I never would have guessed a knock noise from the top end. That could definately explain what's been going on here in all the camshaft research. arty: Good info! :yahoo:

I think this topic should win some kind of most interesting award or something. :good:

 

[joedrum]

yea theres been a lot of discussion ....but i want to get one of these loud mouth motors to shut up ....im hopful but and we have gotten to thepoint of cams changing the sound or carictor of the noises .....till one of us gets some kind of improvment to the springs going on i dont think were going to get any further ...im thinking that spring change is going to be big step it may not cure all the noises ....but once known that its not the top end anymore will be huge step good or bad to a picticular motor..... :mrgreen:

 

[dan filipi]

That's interesting Gerry.
So it sounds like we're on the right track.

I'm going to do that same test with the springs.

 

[mcgovern61]

My dilemma.....I have an '81 engine with no way to verify these items. I am not pulling my great running '83 out now...too much time invested and its one of those "if it ain't broke..don't fix it" deals. I do not have another set of carbs to even try running the engine out of the bike.

I do desire to have a Standard along side of my full dresser...so maybe a non-running parts bike that I can drop this engine into? (Like I have money to throw around!

 

[joedrum]

im diffenitly going to set up a place in the doghouse to hook a wing motor up and run it on the bench so to speak ...ive just about got that setup done to the 83 with tank and everything out but hook up to run and to be able to get at stuff :mrgreen:

 

[danf]

Of course! The vacuum leak! :doh:

We have a smoke machine at work. It heats up an oil solution (like baby oil?) and connects to the car battery for power. It blows smoke out of the end of a hose that you can attatch to a vacuum port, or where ever you need. It's only capable of pressurizing about 2PSI, but that's enough with the car in the shop and the doors closed, with a flashlight you can see any place where the smoke comes out. I use it to find leaks at intake manifolds, gaskets, hoses, I even find leaking gas tank seals with it.

I like what he said about the weak springs wearing the cams. That makes sense. But I never would have guessed a knock noise from the top end. That could definately explain what's been going on here in all the camshaft research. arty: Good info! :yahoo:

I think this topic should win some kind of most interesting award or something. :good:

That's the coolest invention I ever saw, I saw some guy's using the machine on youtube..like it.. :grin: :grin:

 

[AApple]

Smoke machines have been around for a while, even so, the cheapest ones are still around $1300... :heat: The original idea for them came about for checking leaks in the emissions hoses on cars.
Some of them do use real baby oil, too, but most of the "require" a "special" oil...yeah right... :mrgreen:
Back in the old days, some of the old farts would blow ciggy smoke down the intake to find leaks...same pricipal, just MUCH safer!(don't ask how I know... :ahem: )

A vacuum leak anywhere below the venturi of the carb would create a lean mixture for sure.

 

[danf]

I was talking to a good friend of mine in Florida that does hot rod work and also works as a professional diesel engineer. I asked him about the exhaust valves being whitish and the pipes bluing and he basically said the same thing here. :music:

However, he went on to ask a few questions and asked if the bike had any vacuum leaks??? I said no (not that I remember??) He explained that he had an engine with similar problems (heistation, white exhaust valves, hot exhaust pipes) and knew that the carb mix should have been OK, timing was OK and everything else should have been OK. he went to take the carb off and found a single hairline crack that was causing enough of a vacuum leak to make the engine run leaner than it should otherwise. Once again he asked if there was any possiblility of a vacuum leak??

I had to think about that and then I realized something that caught my eye when I first got the bike. There was smoke in the garage after a startup and I remembered some of the smoke getting sucked in at the intakes! (This was at 2000 RPM during warm up) I also remember pulling the carbs off several times and not replacing the o-rings on the intake to heads, just re-using them with a little vasoline to buy me some time and then not replacing them. #3 hissed at one point and I tightened down on all of them, but maybe they still had some leaks. :swoon: :rtfm: :whip: :blush: :doh:

This lead to an overhead cam conversation and timing and he asked about the condition of the springs! I explained that #3 intake was easy to compress. He said they probably all need to be replaced and to be careful on an overhead cam engine, "THE VALVES CAN FLOAT REAL EASY IF THE SPRINGS ARE WORN EVEN A LITTLE." Further he said, (and I quote) "IF THE SPRINGS ARE WEAK AND THE VALVES START TO FLOAT, YOUR CAMS WILL WEAR UNEVENLY AND YOU WILL GET WHAT SOUNDS LIKE A KNOCK AT THE ROCKERS"! :salute:

Is there a measurement height on the springs? :grin:

 

[slabghost]

1.72" outer springs 1.58" inner springs
1.67" no good 1.54" no good

 

[danf]

1.72" outer springs 1.58" inner springs
1.67" no good 1.54" no good

Thank you sir..most helpful..all of this information is most helpful..

 

[slabghost]

What I would like to know is a low cost source for replacement springs. Maybe car springs that don't need help of the inner springs?

 

[danf]

What I would like to know is a low cost source for replacement springs. Maybe car springs that don't need help of the inner springs?

yep, maybe off some honda car's toyota's ??? Has nobody figured this out yet??? ha ha :smilie_happy: Let's get to work fella's..I'm sure they still sell those oem spring's Right????

 

[slabghost]

Got to be now. Just about every infernal combustion engine these days has aluminum heads. So something should have suitable springs.

 

[scdmarx]

Some of them do use real baby oil, too, but most of the "require" a "special" oil...yeah right... :mrgreen:
Back in the old days, some of the old farts would blow ciggy smoke down the intake to find leaks...same pricipal, just MUCH safer!(don't ask how I know... :ahem: )

We just bought some more oil for ours today for $68. Supposed to have some kind of dye in it too(?) But the last one lasted 7 years or so. It wasn't my call, but I'm sure just about any mineral type oil would've worked.

I used to blow cigarette smoke into carbs to find plugged passages. Back in the good 'ol days when there were cigarette butts all over the shop floor. :whistling:

 

[mcgovern61]

I feel like I am being watched by Ackmed!! :cool!: :ahem:

 

[mcgovern61]

I talked to my buddy again specifically about the cam wear as it relates to valve float. He said that you can tell if you are experiencing valve float at high speed be feeling the cam lobes. On intake valves, just past TDC and on exhaust valves just before TDC, you will feel what seems like a square (across the lobe) flat spot followed by a divit in the lobe. He explained that this is caused by the valve and spring kinda wobbling (if you will) in many directions (kinda like a guitar string when plucked) that stays in motion. As the cam compresses the spring by pushing the rocker while the spring is kinda vibrating, it actually cuts the cam lobe ever so slightly. (He said it takes a long time to develop the flat spot and divit.)

Evidence of this can be found at oil changes....the oil will sparkle real pretty, but it will be hard to pick up anything solid. For any of you that may remember, my oil changes were getting real sparkley! (Real pretty in the sunshine :smilie_happy: )

He recommends Joe's method of just hand grinding the cam lobes smooth with emory and then polishing them. As far as springs, he still says replace all of them...do not get used springs. I told him the mileage was around 169k on this motor and he said "THAT ENGINE DOESN'T OWE YOU A THING!" He was kinda shocked to hear a Goldwing motorcycle engine could go that far. I told him there are Goldwings with 200K miles out there!