Valve Clearances?

[Smiley]

All,
I know this has been covered before, but I can't seem to locate the previous post. I have a Touring 150DE, and was thinking I had better get the valves adjusted, since its got 2500km on it and Im getting what I believe is blow-by. Could someone tell me again what the clearances should be? And, is it in inches or millimeters?
Thanks,
Pat

[rick8150]

Smiley

Here is what I posted back in Jan 2007

After reading various forums and looking at a couple of downloadable GY6 manuals, it seems there are no set in stone valve lash specs.

The tag under the seat on my Tank Touring 150 says .18mm for exhaust and .03 for intake, yet the manual has a reference to .12 for both valves.

In the downloaded Service manual by Carter Brothers (www.carterbro.com) for the Talon 150 series 4-wheeler that has a GY6, It says Valve lash .08~.12 It also has a great engine section with high quality photos.

On another forum they were saying Intake .03~.05 Exhaust .05~.06

So I guess setting them both to around .07mm or .003US should be fine.

Also according to other forums where this GY6 150 engine is used in various machines, it seems that about half of them have the valves sink in after as little as 10 hours. So if you are having idle problems, hard starting, rough running, ect. Check your valve timing.

I'm kinda surprised I have not seen that mentioned here, or I might have missed it.

So mine has been running fine since I set them back in January when it had 3716km, it now has 7430km.

[Smiley]

Rick,
Thanks for the response. I was beginning to think I was being ignored!! LOL. Mine has around 3800km on it and Ive never adjusted the valves yet, its always ran fine, but I've been getting a good bit of oil coming out of it through the air breather. So, I am thinking its time for a valve adjustment. I just havent had time to tear into it, it seems its more of a hassle to get TO the valves than it is to adjust them.
Thanks again Rick.

[rick8150]

I will have to admit that I forget to keep up with the postings on here as long as my scoot runs fine.

Mine has been leaking, or should I say blowing a small amount of oil out of the bottom of the engine cooling shroud. I suspect on mine it comes from the bottom of the valve cover, because of the angle of the engine the oil has a tendency to lay in this area.

It collects on the plastic skid pan above the kick stands and drips a drop or two while parked over night. but it never seems to need oil added between changes, which I do when it gets dirty looking.

It is not all that difficult to get to the valve cover. I just take off the grey plastic shroud that is between your feet and goes around the gas cap and also around the base of the seat at the front. I also remove the inspection cover under the seat that looks straight down on the engine.

I did not attempt to find the timing mark/marks. I could see the cam shaft fine, and when each lobe's high point was dead opposite of the lifter I set the valve clearance. Not the way it's suppost to be done but it works for me.

By the way you will need a valve cover gasket. I got mine and other items I need from Stan at www.oregonvintage.com

Hopes this helps some.  

[Boomerang]

Is this valve cover gasket needed every time the clearance is checked or can't it be reused? It looks like a rubber gasket on the photo.
I have had a Honda Dax 50cc and I always reused the gaskets with no problems. I did the clearance check every 8.000 km. They were rubber too but it had two little caps for each valve and I am not sure how it looks on my Tank Touring. Seems to be one big cover with one big rubber seal. Are you sure it is not reusable? Otherwise I need to buy a bunch of them for future checks.

I also experienced the same thing that oil is coming out the air breather in very small amounts. Too little to go after it but too much not to be worried about. But I can't imagine how this is supposed to be related to the valve clearance.

My Tank has 3350 km on the clock but I haven't checked the clearance as the engine just runs fine. Only maintenance on the engine are three oil changes so far. I hope I'll have the same intervals of 8.000 km for valve clearance checking. If that is enough for a 50cc four stroke it should be on a 150cc.

[Sparky]

There should be a metal plate somewhere on the scooter with the engine info on it. It lists the type of plug to use, the plug gap, and the valve clearances. On my Tank 250, it is mounted on the wall of the under seat compartment.
The Chinese manual for the 150cc calls for valve clearance adjustments at 1000 km, 4000 km, 8000 km, and 12000 km. It lists the intake and exhaust clearances as 0.12 in, and 0.12 out. (cold system) It also says to adjust the 'cam chain' at these intervals.

[rick8150]

it's one big o-ring type gasket. It is not of very good quality, as in thin slivers of rubber protruding from it at intervals along it as though the mold halves did not fit tight togather when they were made.

plus after 3700k it did not look as though there was much of it protruding above the groove in the valve cover.

so I don't think I would trust the old one not to leak if re-used

Rick :?

[tazmo8448]

this is way too confusing...I've adjusted automobile valves and when this number is up adjust that one and so forth and so on....every where I go I see different numbers I have several 48 bladed feeler gauges and no where is there a .05mm(.0025in) they all vary like the numbers I see...not knocking anybody but you would think a 150cc GY6 would be somewhere I hear .004 intake .005 exhaust and there ain't no animal like that on the gauges I have

[chris-bob]

The gy6 manual calls for .05mm intake and exhaust.  That's .002" clearance.  Normal automotive gauge sets will not go that low because they use plastigauge for those clearances.  You need to specifically purchase a set that has those gauge sizes in it.

[Fox]

I'm a pro mechanic specializing in the 50-150cc air cooled GY6. For 7 years now I've been setting them to .003 in. Exhaust and Intake: .003 in.  Truthfully, anywhere between .002 in. and .004 in. will work. After a while you get to where you don't even need a feeler gauge. One guy a while back didn't have a feeler gauge so he mic'd a strip of aluminum can and it was .0032 in. He used that and it worked. The main thing you want is for there to be a tiny bit of play without a loud tapping sound at idle.

[tazmo8448]

gotcha so anywhere from a .05~.10 mm....that makes a lot more sense and it surprizes me how small that really is...no wonder these things if off a little like to rattle a lot

[silverfox96]

My first post on this forum.   My chinese scoot has a gy6 based engine, 150cc.  I set my valves about three weeks ago.  The shop set them at .004 I and .005 X.  It clattered so badly I just couldn't stand it!  Did some reasearch and consulted a few manuals, (Arrow seems to be the best)  Manuals recommended between .08 and .12mm.  I set both intake and exhaust at .10mm and it runs great, with no clatter.  I did have to order a set of metric feeler guages from Napa.

[Fox]

My first post on this forum.   My chinese scoot has a gy6 based engine, 150cc.  I set my valves about three weeks ago.  The shop set them at .004 I and .005 X.  It clattered so badly I just couldn't stand it!  Did some reasearch and consulted a few manuals, (Arrow seems to be the best)  Manuals recommended between .08 and .12mm.  I set both intake and exhaust at .10mm and it runs great, with no clatter.  I did have to order a set of metric feeler guages from Napa.

Yeah, these things can be tricky. It's a trial and error thing sometimes to get them to stop clacking. That's why I wrote "may require a couple or more attempts to get it just right"

[tazmo8448]

yeah I had to set em a few times to get it right and there still is a faint rat a tat so like the man said it is like there really is no set in stone number but something ya gotta tinker with and lets not go into what thats like the tinkerin part.....but it is a starting point....