Valve adjustment

[justin4]

I am not a dumb man ( others may not agree but screw them) I have been working on this 200s for some time, I have the correct feeler gauge the manual and can read it says .05 turn the set screw until you feel drag then tighten the locking nut ,the problem is I has compression coming out the carb . I don't want it to be rolled into the yard and burst into flame but a man can only take so much. Should I use a larger or smaller feeler or what. Help. Thanks for your time.

[dougspcs]

Is this by chance a machine that has been sitting unused for a long period??

I've had a couple of barn find machines that I've bought that had valves sticking open from lack of top end lubrication due to their long period of dormancy!!

The other possibility is that you have a bent or chipped valve, a damage valve seat..the list goes on.

What is the back story on this? Is this a routine valve adjustment or after completing a repair or to solve a problem? Have you done a dry/wet compression test?

[El Camexican]

The “dumb” thing is off the table, so don’t get fired up if it sounds like I am answering a child here. You say you have compression coming out of the carb. Can you feel it, or does it just sound like it is coming out? There is a sound that vacuum makes that may be confusing you. There may also might be an ever so slight push of air out of the carb as the intake valve closes while the piston is coming up to compress, but it would be so minimal on that engine I doubt you could notice it. I don’t think the cam would be that radical on that engine, but I could be wrong.

To adjust the valves the piston should be at TDC on the compression stroke so that you know that the valves should be closed. (that may not be the way the manual says, but it should work). I don’t know what your valve specs are but 0.004” intake and 0.006” exhaust should be nice and safe. These are thousands of an inch, not mm!

Back off the adjuster jamb nut and turn out the screw. Insert the desired feeler gauge in-between the adjuster screw and the end of the valve stem and gently turn the screw in while you slide the feeler gauge in an out a little. Do this until you feel resistance, not until its tight! Holding the adjuster screw ion place lock the jam nut. Insert the feeler gauge in-between the adjuster screw and the end of the valve stem and make sure the feeler gauge still fits without having to be forced and also that you can’t fit an even larger feeler gauge in there.

Do both valves, then make sure the spark plug is installed and put your hand over the carb and crank the engine slowly. It should try to suck your hand in at some point, not push it away. If you feel air trying to come out of the carb and you have no compression at all you likely have a bent valve. If you have compression and it still tries to push air out of the carb you may have skipped a tooth on your cam chain. Did you do ANY other work on the engine since it last ran?

[justin4]

I was trying to do just maintenance , not a barn find, just a machine that was sold to me as running. Well I did the carb changed the plug and still had a very wet plug and would only start with starting fluid. And it ran bad. I have not pulled the topend apart yet. The carb is almost backfiring through the carb just no fire. Like the compression is coming out the carb. I cleaned the carb. The dumb thing is just aggravation . Thanks for the help. I am resetting the valves . It's got good compression .

[Dave8338]

Sounds like it is out of time. You shouldn't have any pressure at the carb, if it is timed correctly. If indeed it has jumped a tooth, You'll likely have to replace the timing chain and hopefully not the cam sprocket, as well. Also, have you adjusted the cam chain tension-er ?

Have you done a compression test on it?

[justin4]

Not yet on the compression test.

[DohcBikes]

For it to be out of time would be very unlikely.

Did you adjust the valves at top dead center compression as el camexican suggested?

In order to be sure you are not the correct stroke, while turning the crank, watch the intake rocker go down, come back up, and stop moving, then continue to turn the flywheel until the timing mark appears in the winow. Then adjust the valves.

It can be tricky, as the flywheel wants to roll right past the timing mark very easily. Do not turn the engine clockwise to get back to the mark, if you miss, go all the way back around twice and try again.

[captain2207]

Op put .05 I think it should be .005.I had same problem with gas coming out of back of carb.I was 180 out.make sure lobes are up on cam with dot on sprocket in line with mark on the housing.it worked for me....yes its aggravating at times.

[justin4]

I took the pull start off because of the mark going just a little past. I will get it. Thanks for all the help.

[justin4]

Success. El camexican I set it up .04 intake .05 exhaust. Three pulls fired up. Thanks again to all who help. I just got 110 125 185 and parts parts parts. If any thing is needed from my large new parts stash do let me know. For those who help shipping is the price. Thanks again.

[El Camexican]

3 pulls? Damn, sounds like your jetting is off.

[justin4]

It may be. Thanks again.