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

[joedrum]

hmmm i like your friends view :mrgreen: yea theres not much worry about hardness ....these cams are cold hammer forge steel now ...i did have great success with the cam trueing ....but again that wont mean a thing unless the springs get done right ... iwill be happy if we can realy figure out a way to fix the top ends good on these motors.....

you would think somebody would have already found a spring sorce ...but we might be the ones that have taken this matter this far ....most would thow there wings away that sound like some of ours do :smilie_happy: :smilie_happy: :mrgreen:

springs springs springs :fiddle: :crying: :mrgreen:

 

[danf]

hmmm i like your friends view :mrgreen: yea theres not much worry about hardness ....these cams are cold hammer forge steel now ...i did have great success with the cam trueing ....but again that wont mean a thing unless the springs get done right ... iwill be happy if we can realy figure out a way to fix the top ends good on these motors.....

you would think somebody would have already found a spring sorce ...but we might be the ones that have taken this matter this far ....most would thow there wings away that sound like some of ours do :smilie_happy: :smilie_happy: :mrgreen:

springs springs springs :fiddle: :crying: :mrgreen:

I only have 53 grand on my springs, I'm not gonna worry with this for a while.. :grin:

 

[danf]

Did you say it was 81 carb's if so I bet you a nickle it's your slow jets, they are clogged, remove them with a easy out tool, tap it in lightly turn counterclockwise using a small adjustable wrench[better leverage] soak em over night, might need a wire off a bread wrapper to clean out the holes they are tiny.. there's your knock..To place back in, simply tap in lightly and turn clockwise to remove tool..Forgive me if you already did this, but that's gotta be it.. :grin: Be gentle putting them back in tap it in but easy does it..Now if these are clogged you can smile because I will grant you that your cycle is going to sound and run really nice, you may have to re- sych. the carbs..Mine knocked like that after I got it I just forgot about that it's been a while.... :grin:

 

[slabghost]

I'm betting this mystery knock has caused the demise of a lot of very serviceable bikes. Anyone with small car repair manuals- please check valve spring height for whatever makes you have. There must be some that use springs that can work. I'm thinking +-.002 of 1.72 spring length.

 

[slabghost]

According to someone on the NGW forum valve springs are the same from GL1000-GL1200 and are still available. I'm hunting a source. I'm still wanting to source similar replacement springs that may remain available long term.

 

[danf]

If this bike is the same one that you have on youtube then it sure sounds like you are sucking air in or have a vacuum leak somewhere, you can hear it in your video, you said a professional did your carbs, even the best mechanic's over look things, your mechanic engineer friend has no idea about the pressed in jets on the 81 unless his messes with them alot, but I'm sure he is totally smart at what he does, I'd remove the carbs and take off your cut off valve covers just to make certain that all the tiny o-rings are there, if one is missing your gonna have problems, sucking major air..check your slow jets, test your spark wires with a mulitmeter, make sure your ground behind the coil is clean and tight, clean up, your ground at the frame bolt that goes to the battery, check your three yellow wires plug out of the stator, make sure your voltage regulator is funtioning by testing it, but it sure sounds like a carb problem to me..I'm not trashing your friend as I know he is much smarter than I am but I like covering everything..Oh and check your dogbone fuse your main fuse, for cracks, that will make your bike run crappy,I'd change over to a blade type fuse..I'm not trying to be a know it all but you really need to cover these things if you want your bike to run correctly..

 

[mcgovern61]

If this bike is the same one that you have on youtube then it sure sounds like you are sucking air in or have a vacuum leak somewhere, you can hear it in your video, you said a professional did your carbs, even the best mechanic's over look things, your mechanic engineer friend has no idea about the pressed in jets on the 81 unless his messes with them alot, but I'm sure he is totally smart at what he does, I'd remove the carbs and take off your cut off valve covers just to make certain that all the tiny o-rings are there, if one is missing your gonna have problems, sucking major air..check your slow jets, test your spark wires with a mulitmeter, make sure your ground behind the coil is clean and tight, clean up, your ground at the frame bolt that goes to the battery, check your three yellow wires plug out of the stator, make sure your voltage regulator is funtioning by testing it, but it sure sounds like a carb problem to me..I'm not trashing your friend as I know he is much smarter than I am but I like covering everything..Oh and check your dogbone fuse your main fuse, for cracks, that will make your bike run crappy,I'd change over to a blade type fuse..I'm not trying to be a know it all but you really need to cover these things if you want your bike to run correctly..

Thanks Beaver, most of this has already been done through the course of the first two years I had this engine in service. I opted to save some time and installed an '83 engine last year.

 

[danf]

If this bike is the same one that you have on youtube then it sure sounds like you are sucking air in or have a vacuum leak somewhere, you can hear it in your video, you said a professional did your carbs, even the best mechanic's over look things, your mechanic engineer friend has no idea about the pressed in jets on the 81 unless his messes with them alot, but I'm sure he is totally smart at what he does, I'd remove the carbs and take off your cut off valve covers just to make certain that all the tiny o-rings are there, if one is missing your gonna have problems, sucking major air..check your slow jets, test your spark wires with a mulitmeter, make sure your ground behind the coil is clean and tight, clean up, your ground at the frame bolt that goes to the battery, check your three yellow wires plug out of the stator, make sure your voltage regulator is funtioning by testing it, but it sure sounds like a carb problem to me..I'm not trashing your friend as I know he is much smarter than I am but I like covering everything..Oh and check your dogbone fuse your main fuse, for cracks, that will make your bike run crappy,I'd change over to a blade type fuse..I'm not trying to be a know it all but you really need to cover these things if you want your bike to run correctly..

Thanks Beaver, most of this has already been done through the course of the first two years I had this engine in service. I opted to save some time and installed an '83 engine last year.

I wish I was closer to you I'd take it off your hand's at a fair price.. :grin:

 

[mcgovern61]

I'm betting this mystery knock has caused the demise of a lot of very serviceable bikes.

I agree! I have seen a lot of 1100 engines on ebay that list a "knock" as the reason they are pulled. As has been said in many forum threads, these engines will knock if the carb sync is wrong, carbs are not adjusted correctly and so on. But I think the springs are an overlooked item. I know that of all the forum searches I have done on 1100 knocking or rapping, the springs are rarely if ever brought up to be checked. I am not saying that the springs are the sole source of our engines that knock, just another piece of the puzzle that we have been working on for a long time! :builder:

 

[mcgovern61]

I wish I was closer to you I'd take it off your hand's at a fair price.. :grin:

Kansas City isn't that far as the crow flys! :smilie_happy: (The gasoline alone to get out and back may cost more than the value of the engine!) :crying:

 

[mcgovern61]

Well through some viseral influence :builder: on a certain un-named clutch nut, the clutch basket is off and the scavenger pump exposed! :shock:


And "SURVEY SAYS"........the scavenger pump and inlet are clean as a whistle! :rant:

Sooooo.....that leaves the valve spring length left to check. I will try to get them off this weekend. I have been doing a lot of research on valve float and I am surprised at how much information is out there! Bottom line is....if the springs are weak, the valves WILL FLOAT!

One engine site pointed out that it is harder to find valve float on intake valves, but you will see intake valve float on the exhaust valves because if the intake valves are floating, it does allow a slightly leaner mixture producing an extended burn into the exhaust. They also said that carbon build up on the exhaust valve will increase its mass hence increasing its potential to float at a lower RPM. They pointed out that valve float is usually first noticed when there is a drop off of power in the upper power band marked by what seems like misfiring. (Maybe what I was confusing with detonation).

Bottom line is, they say if there is any measurable change (more than 10% over OEM original spec) change the springs! (BTW- I narrowed down this research to SOHC engines only) :laptop:

 

[mcgovern61]

I did the oil pressure test on the '81. I have never tried it on the '83. Considering that the scavenger pump inlet was clear on the '81 engine, I might have to hook up the '83 and try that test again and see if the results differ. I just have to make room in the garage to even be able to pull the bike out! I should probably wait for warmer weather since it is averaging 28 degrees here. (Don't want to influence the result by having a real cold engine and real thick oil)

 

[dan filipi]

That could explain the exhaust bluing.

I wonder though, at what rpm's are they referring to float causing these things, 7-8k or more?

 

[danf]

First thing I would do if I'm you is get more room to work, here are some things I did in the past because I had so much stuff in my garage [good stuff too], I went thru everything and got rid of stuff I didn't need, the stuff left [lots] I got a storage room for three months [$ ] and moved it all, I was so happy with all the room when winter left I built a storage room in the back yard for the stuff in the storage room and it's still in there..Lot's of room now.. :grin:

 

[danf]

Now if you sold that engine you'll break even, .. :grin:

 

[mcgovern61]

That could explain the exhaust bluing.

I wonder though, at what rpm's are they referring to float causing these things, 7-8k or more?

These engine sites are talking 6000 RPM on up. Mind you, they are discussing car engines. Only one site referred to motorcycle engines and they were not Goldwings or even boxer engines, just SOHC engines.

Some where back in this thread it was mentioned about a spring staying compressed for a long time from a bike sitting. Makes a lot of sense if the bike sat for years (and this one did) and it then was run like a racing bike (which this one was). The kid I got this from took it from an Interstate and tried to make it a racing bike. He said his brother had it before him and it sat for years in his garage. The PO before his brother drove it everywhere which is where I believe it got its high mileage. The PO I got it from wasn't really sure of the mileage because the odometer did not match the title. After a title search, I found out it had at least 143K before the first time the kid registered it in PA.

High mileage, sat for a long time and then raced at redline? Sounds like a formula for worn out springs to me!

 

[slabghost]

yep! Sounds like just the recipe for it. I'm told the 1200 springs are the same so if you can find some low mileage heads for a good price you'll have all the springs. New are still available but run $5-8 each. At two per valve that's over $100 easy.

 

[joedrum]

so your saying one 5$and one 8$ spring per cylinder ......yikes :rant: :rant: :rant: ouch :mrgreen:

 

[slabghost]

Not exactly. There are several suppliers. Generally it seems one spring will be a dollar less than the other. I just quoted the lowest and highest prices I've found so far. I'd like to find a seller with a good price on a complete set. :head bang: No luck yet. :head bang:

 

[mcgovern61]

Well I have pulled the right side springs and found a few interesting things:

#1 Intake and #3 Intake valves are pounded down at the seat to the point that they are almost razor sharp. (But the seats are clean and shiney)

The back of #3 intake is covered with carbon (almost 20% of the diameter of the stem wide). #1 intake also has carbon on the back but not too bad.

#1 and #3 exhaust valves are pounded and mushroomed round at the seat. They still have meat on them that they could be ground down and trued up again. But, there is carbon smashed into the seat surface on the head and the valves leaving an uneven surface.

Both exhaust valves are covered in hardened carbon and #3 is white as a sheet!

The outer springs are all within tolerance according to the manual. But the inner springs are well below tolerance (Original length 40.2mm - Limit is 39.0 MM, inner springs are 37.8mm average)