Springs and cams

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)

Here are some pics of the #3 seats. Notice the carbon pounded into the exhaust seat.

#1 cylinder


Digital cameras have their place, but I cannot get mine to focus close up, it keeps looking at the background for focus. (Tried macro and that did not help) Here is the right cam. Look at the way the lobes are worn.





The #3 exhaust valve:


The #3 Intake valve:

I found a local M/C repair shop that I took the right head, valves and springs to and he is going to see what it would cost to replace the springs, clean and lap the valves and head and smooth the cam. He agrees the intake valves are beyond saving, not enough meat. He said he could do a compression test on the springs if I can find out what their original compression was. He said either way, at 169k miles, he recommends just replacing the springs anyway.

He gets a lot of Harley work (8 in his shop at the moment) and laughs. He said that the Harley engines "are not engineered like Jap engines". He claims that Harleys are designed to be rebuilt by 70K miles. (And they keep him very busy...even in the winter) His experience with Goldwings is they do not need rebuilding until 200K miles if highway. Top end work is normal at 120K in his book. He did not hear this engine run, but after we talked he is still under the opinion that there is lower end stuff going on. The only way to find out is to split the case. :crying:

I may not split the case until spring (when I might have more time and room). In the mean time, anyone looking for an '81 engine that might need some work?? Price is right....free if picked up by a member! 160's compression on all 4. :builder:

wow you can sure see a lot from the pics ....the cams dig in hard at the start and tend to come off the cam on some of the valves and realy just lightly toching on others .....it seems to me that this is where the most wear is on the wing motors .....good stuff gerry :mrgreen:

I agree with the shop the seats could be lapped.
Valves may even be reusable but probably not worth the risk if one would break.

Your cam lobes look just like almost every one of the 10 cams I have, except for the 1200 cams which look near new.
What did he say he'd do to true them up?

dan filipi":3fs8d9od said:

I agree with the shop the seats could be lapped.
Valves may even be reusable but probably not worth the risk if one would break.

Your cam lobes look just like almost every one of the 10 cams I have, except for the 1200 cams which look near new.
What did he say he'd do to true them up?

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He said he would do the same as Joe, hand grinding with compound and then polish. He doesn't think the cam lobes are real bad considering the mileage. He has seen much worse.

The one thing we noticed (and I forgot to get a picture of) the valve rocker adjusters are very worn and pitted on the bottom.

I don't know maybe it's just me but I don't have a lot of faith in surfacing a cam lobe by hand.
Would such a job last 100k miles?

I'll throw my $.02 in...I might need change back, tho...
I wouldn't install a "new" valve in an "old" seat, lap it, and expect it to seal properly. Unless the seat AND the valve are ground properly, at the same angle(s), chances are it will not seal well, imho....especially when I see valves that have been hammered into the seats that bad. The seat will be damaged also....it's just harder to see/visualize.
If this were my engine(and it ain't), I would go ahead and get the "new" valves, then grind valves and the seats to match....
just my opin... :mrgreen:

I think that valve is history. The seats can be cut, depending on how much metal has to be removed to get rid of all the pitting. Don't forget about the guides - that motor has a lot of miles on it.

McGovern61, I found that if you stand back aways with your camera & use the zoonm you will get clearer pics than having the camera almost on top of the subject. arty: :smilie_happy:

i think your looking at it wrong dan once you get trauma level down .....the cam is not going to wear anyway ....cams being pounded are going to be hard just from that ....the molicukes will be tighter and closer to gether .....this is just as important in hardness as steel content ....in farming pretty welds dont keep things together as good as short burst of welds and instant hammering as soon as the rod is lifted .....it always makes me laugh whem so called certified welders cant weld good enough for 200 horse pull at the drawbar from tearing up there welds or they get it to hot from a long bead and it breaks right next to the weld ....

doing it by hand is the best way to keep the cam as hard as possible ....i dont know about 100k but it well last a long time ....maybe longer than 100k...who can answer that .....

its obvious that even tho the wing can rev rather high in the rpm ....the springs are the weakest link period....causing the cams to get hammerd .....and then theres the one long sitting spell that take a spring out because it has sit for forever with the spring compressed ....that probably takes that spring out and done for good

im thinking seriously about ....putting in a sight glass on the crank timing plug permenitly and marking the crank in the best possition possible for the springs...thats proably the sinked in possition of clylinders all the way around ....so when its parked for a long time it can be possition in the best spot and not clobber a spring all the way compressed...... :mrgreen:

Think of hand lapping the cams as using sanding block to get body work completely smooth. Using a whet stone to smooth out the damaged area on the lobes is the same principle and absolutely will not affect the hardness. Followed with finer grits and polished smooth will make them function like new again. I'll try to make a thread with pictures soon. Joe is absolutely right in this.

I just don't see how the lobe can be made flat and square so the followers contact evenly by doing this free hand. Guess I'd have to see it done.

no machine is as good as a talented hands and a keen eye and the patience and touch a machine cant match :mrgreen:

fysty-1":2ccha5k9 said:

McGovern61, I found that if you stand back aways with your camera & use the zoonm you will get clearer pics than having the camera almost on top of the subject. arty: :smilie_happy:

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Thanks for the advice! I gave that a try....but it still keeps autofocusing on the background. :rant: There must be a way to make the focus manual! :cheeky:

(I miss my good old manual Canon T-50) :crying:

"SURVEY SAYS"....the verdict is in......valves are way past their wear margin (no surprise there). The inner springs are shot (no surprise there either!) Parts that need or should be replaced:

*All 16 springs....about $7 ea average
*All 8 valves.....intakes are about $15 ea aftermarket, exhaust are only available from Honda...they are hardened valves at a cost of about $30 ea with tax! :shock:
*Valve guides should be replaced
*Cams ground smooth
*Heads resurfaced
*All valve adjusters need to be replaced (all of them are either worn or pitted) at about $12 ea.
Total for just parts alone is about $400 with tax for both heads! :shock: (Not counting head gaskets or any other gaskets or seals)
If I include his labor the total job could run up to almost $900!

And I haven't even split the case yet to see what else needs to be done! I found grit in the worn down clutch plates. I know the water pump seal needs replacing along with the cam shaft front seals, water tube o-rings, complete gasket kit and who knows what else in the lower end. This is a high mileage engine that has seen it's best days already.

It is time to make a donation to whomever would like it, it has served me and my daughters well! We learned a lot and had fun learning!

This engine owes me nothing! :yes: :thanks:

I'd love to have it but alas. It is a bit far from here. Oh well. :builder:

That engine sounds too tired to be worth anything besides scrap metal value.

I've been hoping you split the case and look at the rest.

dan filipi":2a4nnj7m said:

That engine sounds too tired to be worth anything besides scrap metal value.

I've been hoping you split the case and look at the rest.

Click to expand...

I will more than likely split the case later this year to take a closer look, but it will be on the back burner while I get my runner's items taken care of for this year (battery, rebuild calipers, hopefully a Mosfet regulator).

In the mean time.....if any one is looking for items or the engine itself please let me know.

mcgovern61":2zjpsml3 said:

"SURVEY SAYS"....the verdict is in......valves are way past their wear margin (no surprise there). The inner springs are shot (no surprise there either!) Parts that need or should be replaced:

*All 16 springs....about $7 ea average
*All 8 valves.....intakes are about $15 ea aftermarket, exhaust are only available from Honda...they are hardened valves at a cost of about $30 ea with tax! :shock:
*Valve guides should be replaced
*Cams ground smooth
*Heads resurfaced
*All valve adjusters need to be replaced (all of them are either worn or pitted) at about $12 ea.
Total for just parts alone is about $400 with tax for both heads! :shock: (Not counting head gaskets or any other gaskets or seals)
If I include his labor the total job could run up to almost $900!

And I haven't even split the case yet to see what else needs to be done! I found grit in the worn down clutch plates. I know the water pump seal needs replacing along with the cam shaft front seals, water tube o-rings, complete gasket kit and who knows what else in the lower end. This is a high mileage engine that has seen it's best days already.

It is time to make a donation to whomever would like it, it has served me and my daughters well! We learned a lot and had fun learning!

This engine owes me nothing! :yes: :thanks:

Click to expand...

It can be fixed a lot cheaper with patience. For example here's a set of exhaust valves. https://cgi.ebay.com/ebaymotors/HONDA-GO ... 43a4aa400f