Nut fell off tappet adjustment screw while driving,how much damage?

[redskinman]

Its only been about 30 minutes of engine time since I last adjusted valves.Valves still sounded like they were clattering too loud so I had a friend come over to help me find TDC and set these right{im new at this} Well we take off valve adjustment caps and 1 of my nuts is missing on the tappet adjustment screw.I was able to take head up high enough without removing engine and found nut laying inside.
Put nut on but now tappet adjustment screw doesnt feel right.When screwing down to adjust valves its too hard to twist,meaning it doesnt twist as easy as it did before.I took a tappet screw out of another engine and tried it and it feels the same way.I was adjusting the valves just by the feel method before because i couldnt get a feeler gauge in there.Now the screw is harder to turn and its harder to do the "feel " method.
Got valves adjusted to where i thought they should be and it cranked and ran for about 10 seconds before dying.Now I cant get it cranked.I tried pushstarting it by myself and it almost fires up but it backfires.
Do you think my valves are just adjusted wrong or what kind of damage could I have done? I dont know why that screw is harder to turn now.It was starting right up even with the nut off right before i started on it and found this problem.

[Thorpe]

EPIC FAIL. Hows the "feel" method been working so far? Anytime you lose a nut into the motor, the damage, has the potential to be massive. First thing, I would find that nut, invest in feeler gauges that will work,

and pray heavily you didnt destroy your motor.

[Headsup]

Go back over usuall things, Check spark for everytime time..

Get a feeler gauge real cheap a couple bucks.
If you where runnin git with the nut inside wow, your lucky it still tries to fire.
Backfireing i would check valves and or jets

[Silverado]

I think I need to buy a feeler gauge, can someone tell me what sizes I need for the 250sx ?

[hoosierlogger]

They come in a set all neatly stored in the handle. They are on a hinge and you swing the one (or combination of them) out to get the size you need.

[Headsup]

Whats your bike? 200x? I think .003 mm not sure.

[Silverado]

Whats your bike? 200x? I think .003 mm not sure.

250sx

There are 4 different types at Napa so I was not sure which to buy

[briano]

oh boy, WOW

[redskinman]

EPIC FAIL. Hows the "feel" method been working so far? Anytime you lose a nut into the motor, the damage, has the potential to be massive. First thing, I would find that nut, invest in feeler gauges that will work,

and pray heavily you didnt destroy your motor.

While i appreciate the respone i dont appreciate the scolding.If you read my post it says I found the nut.I have a manual and have been reading it.I was suggested the "feel " method on here because its so hard to get feeler gauges in there.Thats not what caused nut to come off,I must not have tightened it good enough last time I adjusted them and thats why it fell off,not because of the way I did it.

[briano]

Did the manual recommend to leave the jam nut finger tight, get feeler gauges and do it right. I have done the feel method before also to get by in a pinch but then brought my feelers home from work and did it right. Think you can feel when you are at .004", doubt it.

[Dirtcrasher]

You sound 180 out, I do not understand why it's so hard to set valves for some people (not necessarily you)

Anyhow, the nut was off so the screw part was ing against the valve end and the threads in the rocker because it wasn't locked down.

You need to use a good screw, re-tap that rocker arm (put grease on it to keep shavings on the tap) adjust it at TDC on comp stroke and lock it down with the nut.

Ensure tightening the nut doesn't change the clearance or make the clearance larger and then tight down the lock nut because most people don't have that itty bitty square wrench to hold that part that hits the valve.

Did you friend understand TDC at a compression stroke versus an exhaust stroke? Sounds 180 out and has some bad rocker threads.............

[Chazz of Blades]

I JUST GOT INSIDE from doing my first valve adjustment, and I used feeler gauges no problem. Guess what? Everything is perfect now. Because I followed advice on here, and went by the manual of course.

What happened could have been catastrophic, and these guys are scolding you, so you won't make the mistake again. They won't have to foot the bill if you destroy your motor, they give advice because they care, not just because they can.

[trashy250]

explain tdc on a compression stroke versus an exhaust.. never really got it?

[shortline10]

Cam lobes are both pointed toward the piston . Thats were you want to adjust the valves .

explain tdc on a compression stroke versus an exhaust.. never really got it?

[hillbilly 200x]

have you tryed to bend the end of the feeler gage so it gets under the adjusters. it will look like an L