valve clearance inches vs MM and oil in filter

[william1313]

I have a Kymco Peoples 50 cc 4T.   Got it around 2009
Live on an Island and I did not do much maintanence until last week when I decided to do it myself.
Watched tons of videos
The topic of valve clearance was very interesting.
Many talk about using .004 inches for the clearance.
The manual, of course is in MM an recommends .04 mm
Attempt #1 I used the .004 inches.   BTW the bike ran quite good before I attempted to fix it.
.004 inches caused very loud tapping.  I feared I was actually damaging something it was so loud.
Next I went t the Manual suggestion of .04 mm and it hums like a bird.    So with the  Peoples 50 cc 4T I highly recomment you use .04 mm.  If you are stuck on inches then .00158 inches.   There is quite a difference between .004 inches and .00158 right?  Its 2-3 x the proper gap size.
As an aside I changed the oil, trans fluid, and inspected the filter which had some oil on it.   I could use some good common sense approach to that.

[CROSSBOLT]

I have a Kymco Peoples 50 cc 4T.   Got it around 2009
Live on an Island and I did not do much maintanence until last week when I decided to do it myself.
Watched tons of videos
The topic of valve clearance was very interesting.
Many talk about using .004 inches for the clearance.
The manual, of course is in MM an recommends .04 mm
Attempt #1 I used the .004 inches.   BTW the bike ran quite good before I attempted to fix it.
.004 inches caused very loud tapping.  I feared I was actually damaging something it was so loud.
Next I went t the Manual suggestion of .04 mm and it hums like a bird.    So with the  Peoples 50 cc 4T I highly recomment you use .04 mm.  If you are stuck on inches then .00158 inches.   There is quite a difference between .004 inches and .00158 right?  Its 2-3 x the proper gap size.
As an aside I changed the oil, trans fluid, and inspected the filter which had some oil on it.   I could use some good common sense approach to that.

The Kymco standard for most 4 cycle engines is .1 mm/.004" from 50 to 300 cc.

.04 mm is generally a book typo error because it is way too small. You probably had the cam in the wrong position when setting .004" because that is generally quiet even on air cooled engines.

[Ruffus]

Here in Italy we adjust
-intake valve 0.10 mm
-exhaust valve 0.12 mm
Too tight, heats up.
Too loose , starting problems, noisy

[CROSSBOLT]

Here in Italy we adjust
-intake valve 0.10 mm
-exhaust valve 0.12 mm
Too tight, heats up.
Too loose , starting problems, noisy

That will work well but not .04 mm!

[Stig / Major Tom]

Piaggio manual says .08mm for all 3 valves of my LIBERTY150.
I do +.08mm > -.10mm.

I tell a lie - .08 makes me nervous so I do .10mm.

Yeah - going to be nice and quiet at .04mm.....until!
My 'tell' is - do I have a little up/down movement on the rocker arm adjuster screws? If they both aren't moving even a fraction - I need to re-do TDC because I may not be there!

Stig

[william1313]

Thank you for your amazingly fast reply.
I suppose it could a typo.  However .04 mm was used more than once in the Manual.

see chapter 3. 

https://absolutelyscooters.net/manuals/Kymco_People_S_50_125_200_Service_Manual.pdf

I am pretty sure I had the cam in the right place because I was so paranoid I would make a mistake I triple checked it.   

The .04 mm feeler felt like aluminum foil so I did question this.   

There are several references in the literature for using .04 mm or near equivalents for example
(see 3.10 minutes into the 6 min video)

see post by tortoise
https://scootdawg.proboards.com/post/229665

https://scootdawg.proboards.com/post/439154

However to your point,  I see several posts saying just what you said.

Very confusing

Bill

[CROSSBOLT]

Thank you for your amazingly fast reply.
I suppose it could a typo.  However .04 mm was used more than once in the Manual.

see chapter 3. 

https://absolutelyscooters.net/manuals/Kymco_People_S_50_125_200_Service_Manual.pdf

I am pretty sure I had the cam in the right place because I was so paranoid I would make a mistake I triple checked it.   

The .04 mm feeler felt like aluminum foil so I did question this.   

There are several references in the literature for using .04 mm or near equivalents for example
(see 3.10 minutes into the 6 min video)

see post by tortoise
https://scootdawg.proboards.com/post/229665

https://scootdawg.proboards.com/post/439154

However to your point,  I see several posts saying just what you said.

Very confusing

Bill

This is from manualslib.com on the People S 50, 150, 200:

https://www.manualslib.com/manual/982143/Kymco-People-S-125.html?page=79#manual

[william1313]

Read page 41 same manual.

There must be some logical explanation.

https://www.manualslib.com/manual/982143/Kymco-People-S-125.html?page=41#manual

[Stig / Major Tom]

Read page 41 same manual.

There must be some logical explanation.

https://www.manualslib.com/manual/982143/Kymco-People-S-125.html?page=41#manual

Chinglish......as .004 becomes .04mm.....typo for metric proofreader program in the printer??
Stig

[CROSSBOLT]

Read page 41 same manual.

There must be some logical explanation.

https://www.manualslib.com/manual/982143/Kymco-People-S-125.html?page=41#manual

Been there, seen that, that and other models starting in 2006 or so. Many errors in operator and service manuals. Trust me! .04 mm = .0016" and a valve stem up to operating temp will "grow" that much. .1 mm/.004" is your target.

Several here tried over the years to get corrections made but were ignored. What could we know? Har, har! Some outfit horned in to write and correct but were largely ineffective.

The biggie early on was octane rating of fuel. Other countries don't have our (R + M)/2 rating system. The book said 91 minimum and the sticker inside the tub under the seat said 87 (R + M)/2.

Kymco is great scoots. Well designed, well made. Their books suck with errors and the importer is in chaos. You will hardly ever need parts and they nearly can't be killed.

[william1313]

ok i will try .1 mm again
here is another post quoting a man who did just that and got loud tapping like I did.

https://www.kymcoforum.com/index.php?topic=6172.0


If I do it and get the loud tapping should I just ignore?

[CROSSBOLT]

ok i will try .1 mm again
here is another post quoting a man who did just that and got loud tapping like I did.

https://www.kymcoforum.com/index.php?topic=6172.0


If I do it and get the loud tapping should I just ignore?

Absolutely not! Like I said before, loud tapping usually means the cam is in the wrong position when setting the clearance. Just because the "T" is in the window does NOT mean the cam is right for setting valve clearance.

[william1313]

so I did 4 thinks to assure I was in dead center

1. aligned the T
2  made sure the arms were movable
3.  made sure the large hole was set equal between valves
4.  made sure the small holes were in line with the case on both sides

Was there anything that I might have missed.   Could the tapping be because the clearance was too large?

[CROSSBOLT]

so I did 4 thinks to assure I was in dead center

1. aligned the T
2  made sure the arms were movable
3.  made sure the large hole was set equal between valves
4.  made sure the small holes were in line with the case on both sides

Was there anything that I might have missed.   Could the tapping be because the clearance was too large?

That confirms you have it in the right position. Could you do a video or just audio and post it here for us .... to hear?

[william1313]

I think one of the biggest annoyances on forums is trying to help people who do not listen or refuse to get it!
I am not one of those people.   But as I find myself continuing to challange the ideas that I am hearing I hope I do not come across as dumb or worse ungrateful.    With that being said:

I scrutinized the 50,125,200 peoples manual again

https://absolutelyscooters.net/manuals/Kymco_People_S_50_125_200_Service_Manual.pdf

On section 3-5 it states this.

Valve Clearance   IN:  .12mm , 50 cc .04 mm
                          EX   .12 mm, 50 cc .04 mm

clearly the author of the text is trying to differentiate the 125 and 200 cc verson of the peoples 50 from the 50 cc model.
I do understand the theory of typos but it would be hard to make a typo in this situation.

Given all this:  I also understand the point that when the engine heat up it will expand by .04 mm and make a zero clearence which of course is not good.   Please be patient with me and take a second to look at this "page 3-5"  I am referring to and let me know if you are still 1000% sure its a typo.   because it means a lot more work for me if it is.   

apologies if I am wasting time and thanks for all your help