My Valves are at .13mm and .15mm!!!!

[TominMO]

Originally Posted by Boatguy

So how do you adjust a valve clearance when the rocker arm doesn’t stay stationary?

As Jerry says, on the compression stroke, there are TWO TDCs in a four-stroke motor, by definition. It's not uncommon to adjust on the wrong TDC.

[Boatguy]

Thread resolution in case anyone else runs into these types of questions.


So what I did was adjust for no play. I tightened it all the way, so the rocker arm had no play in it at all, then I backed off until the .06 fit in there and the .08 did not.

Seems to have worked perfectly. That tendency for the xpect to stall at cold idle vanished.

I still get a few little “pop pop”s when downshifting to a stop, but they are quiet. I had always hoped they would go away after this.

In general, the bike just sounds smoother now. It used to sound more rough.

Another thing I noticed was my spark plug was kind of loose. Definitely was not torqued to a normal level.

I did the backroad development style and greased its very dry threads before putting it back. It’s a little gray/white looking on the cathode, so I’ll be replacing before my big trip.

Thanks for staying with my thread through the panic. When you are working on your bike outdoors in a place that you can’t just relax, everything gets a lot more tense.

[Boatguy]

Originally Posted by TominMO

As Jerry says, on the compression stroke, there are TWO TDCs in a four-stroke motor, by definition. It's not uncommon to adjust on the wrong TDC.

I verified this one by looking in the hole. LOL easy enough to see the piston right up there all the way at the top.

[J4Fun]

Just a thought here, my Hawk DLX manual says valve lash, 0.05-0.07mm. Tire pressure is front 32 cold, back 40 cold. Both tires say 32 psi maximum. To make my point I think the manual is more generic than it should be including valve lash. Seriously you need too pay attention when it comes to maintenance on these bikes, language is a barrier I believe?

[Boatguy]

Originally Posted by TominMO

REVISED POST

I use inches, so .006" = .15mm.
From inches to mm, you multiply by 25.4 (I use 25 even).
From mm to inches, you multiply by .03937008 (I just use .04). Or divide by 25.

My intake is .004"/.10mm. Slightly loose I admit.

My exhaust is .007"/.175mm. That's a little loose for sure, but it gives plenty of margin for expansion. Exhaust valves always get hotter, so the valve stem expands more and closes the gap more.

I'd say to tighten up the intake to .06mm, exhaust to .08mm. I prefer just a hair looser, in case I goof up a little. Better too loose than too tight.

Just checked my Clymer Manual model #M315, for Honda 100cc - 350cc OHC singles, 1969 - 1982.
https://www.amazon.com/Clymer-Public...ps%2C99&sr=8-1
On page 52, Table 8, Tune-up Specifications, it lists these specs:
Intake (all models): .05mm/.002"
Exhaust (100 and 125cc): .05mm/.002"
Exhaust (175 - 350cc): .08mm/.003"
So even though these are pushrod bikes, not OHC, I think the numbers should stay the same. Might tighten mine up a bit.....

Well, damn. I went for .06mm across the board. It seems to run OK cool. I’m going to have to take it out really hot and see if anything changes.

If I had just left it alone, it would have been a lot closer to how you adjusted yours.

I guess I’m going to go thrash it at 55 miles an hour, 7300 RPMs, for a while. See if it continues to run properly.

[TominMO]

Originally Posted by Boatguy

I verified this one by looking in the hole. LOL easy enough to see the piston right up there all the way at the top.

On the correct TDC, both rocker arms are loose. On the wrong one, the exhaust rocker will be tight.

[Boatguy]

Originally Posted by TominMO

On the correct TDC, both rocker arms are loose. On the wrong one, the exhaust rocker will be tight.

This should be simple to visualize, but I’m not visualizing it.

The TDC I was going for is where the intake has just opened, the piston goes down, then the intake closes, and the piston goes up. Max compression/sparky time. That’s the TDC you want right?

When everything is closed up. No valves open. On every motor I have worked on, that’s the TDC I have used. I think. If I remember correctly.

EDIT: After putting mine into better words, I can see yours as well. The wrong one, with the exhaust valve open (exhaust rocker tight), is TDC at the end of the exhaust stroke.

People are going to laugh at this thread when we have all electric motorcycles soon. Lol

“What are those old men yammering on about? Compressing gasses? Valves? ?? How quaint!”

[herbie]

This page is out of my Lifan KPR200 owners manual. I set almost all my clearance's at this it's kind of a default setting for me. .08mm intake .12mm exhaust. I always use the go no go method, meaning choose the correct feeler gauge needed and adjust to you feel a drag as you pull it out now get the next size bigger and try to reinsert it, if it doesn't go then your good to go, if it does slide in you have to readjust until it will go to correct measurement but not go on the next size bigger.

[TominMO]

Kudos to Franque BTW, for being right all along.....

[TominMO]

Originally Posted by Boatguy

This should be simple to visualize, but I’m not visualizing it.

The TDC I was going for is where the intake has just opened, the piston goes down, then the intake closes, and the piston goes up. Max compression/sparky time. That’s the TDC you want right?

When everything is closed up. No valves open. On every motor I have worked on, that’s the TDC I have used. I think. If I remember correctly.

EDIT: After putting mine into better words, I can see yours as well. The wrong one, with the exhaust valve open (exhaust rocker tight), is TDC at the end of the exhaust stroke.

People are going to laugh at this thread when we have all electric motorcycles soon. Lol

“What are those old men yammering on about? Compressing gasses? Valves? ?? How quaint!”

[JerryHawk250]

Originally Posted by TominMO

Kudos to Franque BTW, for being right all along.....

That Franque guy knows his chit! lol

[franque]

I try, but I'm not sure what I did here?

[JerryHawk250]

Originally Posted by franque

I try, but I'm not sure what I did here?

You did, just in another thread.

[Boatguy]

The test ride is done!

Final report:

It feels like I just dropped a brand new Honda engine into this thing. I cannot believe how smooth it runs now. There is no more cold stalling anymore. I used to have to crack the throttle just a little bit whenever I took off in first gear. Like before I even let the clutch out. Just to get that engine spinning. Now, I barely have to do that at all. I was compensating for the loose valves for all these miles.

And the sound! How can it I possibly sound this smooth? It’s really a beautiful sounding engine now. It sounds more reliable. Just because there are no weird valve sounds I suppose. It had them ever since day one. I figured that was just the Chinese tolerances.

It also seems to grab a little bit faster when you put the throttle on hard. Less hesitation.

I’m a fan of .06mm/.06mm. Seems just right for this bike. And I definitely did a perfect tolerance where the .06 slides in and the .08 will not. Hope they stay like this for a long time. When they do start going, if they do, I’ll be able to notice it a lot faster now.

Test ride was about 45 mins of near WOT doing 60mph at about 8000RPM, plus in town hills and stop and go. To really heat it up and wind it out to check for any problems. There were none.

[TominMO]

Originally Posted by franque

I try, but I'm not sure what I did here?

In the thread on my Xpect, you gave your opinion of the proper valve clearances, which I now agree with. Pretty much anyway. I'd say for very hot weather go just slightly looser, esp. on the exhaust side.