Was adjusting valves, told .005 on both from Raceway. Flywheel has 2 marks, an "F", and a "T" if I am reading correctly, not very far apart on the wheel. I lined up on the "T." Then adjusted both to .005. Fired up and is chattering bad. Too loose? Did I use wrong mark on flywheel? Have seen .002 and .004 used a lot on here. Thanks for any information.

 

i think its suppose to be .002? but if thats what Raceway told you.....
when you set it at .005 was it so the gauge would just barely fit or was it kind of loose?

 

I searched previous posts, found Honda seemingly spec'ing at .002. Most common I found was .004 I think for what people are using on these smaller quads. I have manual on a Redcat 50 that says .004 intake and .006 exhaust. Talking through receptionist? to John at Gateway, he said .005 on both. So that's what I did. Guage fit snug, was able to get it in with a little work after tightening. This thing has run great till this winter, hard to start. Have been adjusting carb mixture and slide per info here. Also did throttle cable adjust-way loose! I am going to try again tomorrow with engine cold. Can anyone tell me if I am using correct timing mark of "T" to adjust both valves? Or do I adjust 1 at "T" and other at ??? Thanks for reply Bastosako.

 

T marker designates top dead center!
F is the full advance marker for the spark, when dynamically testing the spark timing with a timing light at mid range around 2500 RPMs.

Back to the top dead center.
That is when the piston it at its highest point.
Now the cam position relative to the crank rotation it is important!
It is not a 1:1 ratio

For every half rotation of the crank is a quarter rotation of the cam!
Intake, compression, power, exaust, 4 important conditions on any internal combustion engine!
In other words the piston must be in the peek of the compression stroke in order to have both valves closed.

To get there rotate the crank in the proper direction, watch the intake valve as it opens, then begins to shut you are entering the compression stroke.
This is when you want to continue and line up the T marker.

The 110cc top end is similar to the old honda S90 engines.
But if the cams may be cut different, the lifter gap will be different!
If the 0.005 inch you have gotten from a reliable source that is what you set the valve/lifter clearance at!

A little loose lifter is better than having it to tight. Especially on the exhaust valve!

The 50cc cam may have a different cut, the exhaust lobe may have higher lift with a short duration with a quick drop off to give it a snappy feel when throttling it and you need a 0.006 inch clearance so the valve will not touch the top of the piston an the exhaust stroke.
I think the old timers called this type of cut a half race cam.
Full race cam the intake and exhaust had a high lift short duration with a quick drop off.
.

 

TommyA300, thanks for reply, will make sure intake is closing and recheck clearances. Thanks for the lesson, just what I needed. If still at .005, may tighten them a bit more. This thing was loud as soon as started, although it started quicker! Half-race cam on the 50's? They do run pretty good. LOL!! Thanks again!

 

You are welcome!
Be carefull not to make them too tight.
The old honda s90 engines had a tol of 0.004 inch. rocker arm to valve stem clearance.
I would not go any tighter than this. It is most likely you caught the timing at the top of the end of the exhaust stroke when you gapped the clearances.
I don't believe that Raceway would give you incorrect info!

Word of mouth travels quick and they would not want to give bad info and have anyone say they did.
Any business will limit the info they give, by answering the particular question asked!

If you make the valve clearance to tight it may cost you an exhaust valve, guide, piston and top end work.

You had done for me a good thing.
Pushed me to read up on cam grinding! I was looking for a formula that determines the clearance.
Still looking!
Several things involved is the cam lob peek, the duration, the dropoff, rocker arm ratio etc... etc...etc...
Pretty interesting stuff.

 

Well, have adjusted them twice so far today. First time exh. was at .007, int. at .006. Think you are right TommyA300, was on wrong stroke. Put them at .005, and fired up, and still pretty noisy. Adjusted again down to .004. Quiet until it warmed up and then a little chatter. Could be something else, but I think it's the valve train. Was debating on going to .003, but I think I will leave it. Anyone else have noise at this setting? Here is something for ya, am at work, sneaking in a wrench here and a wrench there as work allows, threw back together in a hurry because of a customer, and left socket on the crank nut. It had a little chatter there also! What a dumba$$!! It is interesting and amazing how these things work, thanks again for help.

 

You are welcome OTSD2Day! Glad to help! Getting your feed back makes it all worth while!
A little chatter is fine! How old is the engine or what I should say is... Is it broken in yet?
Ah ha Things happen sometimes to us all! Aaaa Do not kick yourself so hard!
When Muli tasking, $_it happens! And always hits us guys when we don't expect it!
I once I did a top end on a 2 cylinder 305 honda back in the late 60s .
I forgot to put the gasket on the lower jug surface to crank case.
Had it all together and started it.
Ran fine except oil ran out from the corner stud where the oil line to the top end is located.
What a mess! I shut it down as soon as I saw it! No damage but my pride and doubled my work efforts.
Play it again Sam!
You are not alone it happens to us all!
Out of all of this that is the one thing that you will never forget in the future! Ironic isn't it?

 

Hey Tommy, engine is about 15 mos with probably 25-30 hrs on it. If a little chatter is fine, I'd better leave at .004, don't you think? I did read on here where one gentleman runs them at .002. Think I will leave alone. If not, pretty fast at it now! Agree with you, these forums are great with people like you helping out, thanks again. Instead of frustration and taking it somewhere and spending, get info from you and back in business. Sorry to hear about that gasket, but no damage is a good thing! Yeah, and I will remember to check for that socket from now on!! Thanks again!

 

You are welcome again OTSD2Day!
Keeps my mind going when I am trying to help, so it is a win win situation.
Yea the Gasket at the time I was feeling sorry too.
It may have happened only once but the experience was a good teacher, it is like burning your fingers with a match, riding a bike or the other thing everyone ends up doing when there is a black out...never forget!

0.002 inch I think is is a little tight.
But now you have the time to find someone with a service manual that gives the correct tolerences.