Author Topic: Valve Clearances - What? Mine are like... a quarter inch? (Read 2908 times)

OakBehringer · « **on:** September 10, 2008, 05:19:52 pm »

Just went to adjust my valve clearances for the first time and was surprised to see their current settings. Before I crank these way down, am I doing something wrong?

I'm pretty sure #4 is at TDC. There is a tiny tiny bit of play in the rocker arms, but absolutely none in #1.

Thanks,
Adam

Sam Green Racing · « **Reply #1 on:** September 10, 2008, 05:33:42 pm »

Turn it another full revolution and try again, you may be on the exhaust stroke instead of ignition.

Sam.

OakBehringer · « **Reply #2 on:** September 10, 2008, 05:34:49 pm »

I've done that. It's.... the same.

bwaller · « **Reply #3 on:** September 10, 2008, 05:39:28 pm »

Remove the plugs will help turning it over. Adjust the valves with the engine cold.

Start with #1 and from the right end of the crank turn it clockwise- let the intake valve open then close then watch for the "T" 1-4 mark on the advance mechanism to align with the pointer on the crankcase. #1 will then be on compression stroke.

Just repeat for each cylinder, clearance is 0.002" for the 400F.

Adjust the camchain with the engine running.

dustyc · « **Reply #4 on:** September 10, 2008, 05:51:46 pm »

You can stick a screwdriver in the spark plug hole(don't let it bind as you move the engine) and verify the piston coming up to determine TDC if you don't trust the last person that set the valves.

OakBehringer · « **Reply #5 on:** September 10, 2008, 06:23:41 pm »

I think everyone is missing the point. The problem is not getting it to TDC.

Look at the gap. That's not .002 inches... that's closer to .25 inches. Every gap on every valve is like that at any rotational point. Isn't that absurd?

Bike pretty much ran fine, except for cyl #1 not firing on cold start idle - that's why the carbs are off right now.m

OakBehringer · « **Reply #6 on:** September 10, 2008, 06:24:46 pm »

I basically just want verification that I'm measuring at the right spot... because it's not even close to what it should be at.

blaster802 · « **Reply #7 on:** September 10, 2008, 06:27:34 pm »

I'm surprised it even ran

ev0lve · « **Reply #8 on:** September 10, 2008, 06:35:43 pm »

Are you sure you're on the right TDC? (I know you said you were) Putting my engine back together and getting it tuned on the first go I had #4 at TDC based on the T 1-4 on the plate. Set the clearances for 1 based on that and everything was out of whack (lot of slop on the rest) until I realized what was going on. 180 degrees around and everything popped into place as far as the valves being adjustable as expected from the manual.

I don't think you can be too off when sticking the gauge in there if you can see the valve and the adjuster you're in the right spot (based on my VERY limited experience).

BTW, for all the folks who've done this a few thousand times, how can you tell other than looking at the cam and puzzling out what's about to hit (probably not doable with the engine in frame).

Quote

Start with #1 and from the right end of the crank turn it clockwise- let the intake valve open then close then watch for the "T" 1-4 mark on the advance mechanism to align with the pointer on the crankcase. #1 will then be on compression stroke

Is giving it a run around the crank the only way to know for sure?

A noob wants to know

Iggy

UnCrash · « **Reply #9 on:** September 10, 2008, 06:37:13 pm »

my 78F had a couple intake valves with quarter inch gaps when I bought it.

It ran like crap too.

bwaller · « **Reply #10 on:** September 10, 2008, 06:38:17 pm »

I quess you have two choices....adjust them correctly, or don't.

OakBehringer · « **Reply #11 on:** September 10, 2008, 06:42:11 pm »

oh my god. I just realzed my problem. I'll explain later when I'm on mycomputer (on iphone now). Let's just say,for now, that it's a total noob mistake. Not TDC, even dumber.

bwaller · « **Reply #12 on:** September 10, 2008, 06:44:22 pm »

Iggy, you want to be at TDC on the compression stroke. So turn the engine over until the intake valve opens then closes (for a given cylinder) then watch through the hole in the ignition plate for the "t" mark to align for that cylinder. At this point both cam lobes are not close to contacting the rockers and when the valves s/b adjusted. Go through the same ritual for all four cylinders.

Sam Green Racing · « **Reply #13 on:** September 10, 2008, 06:47:05 pm »

Well hurry up, I'm off line in three hours.

dustyc · « **Reply #14 on:** September 10, 2008, 06:47:37 pm »

You're measuring in the right place. I'm not convinced you're at TDC for that piston. It sounds like you're one stroke off. I'd determine 100% that you're at TDC for whichever piston you choose and reset them.

Can't wait to hear the story.

scunny · « **Reply #15 on:** September 10, 2008, 07:00:45 pm »

what's an i phone

dustyc · « **Reply #16 on:** September 10, 2008, 07:04:31 pm »

Scunny, we have these things here in the states that you implant in your body. It started with the Eye-pod for music videos that play in our heads, now it's evolved into the Eye-phone so we can talk to friends and be on the internet. We just abbreviate it as I-pod and I-phone to save keystrokes.

Wanna hear my explanation of Bluetooth?

scunny · « **Reply #17 on:** September 10, 2008, 07:13:15 pm »

I'm game

by the way... we do have telephones here in NZed

Sam Green Racing · « **Reply #18 on:** September 10, 2008, 07:14:18 pm »

They'll reach you in time

Canada · « **Reply #19 on:** September 10, 2008, 08:42:03 pm »

He wasn't measuring the gap. He was measuring the distance between the rocker and the the top of the valve. He Figured it out. Innocent mistake. Welcome to the world of mechanics.

dustyc · « **Reply #20 on:** September 10, 2008, 08:50:30 pm »

Quote from: Canada on September 10, 2008, 08:42:03 pm

He wasn't measuring the gap. He was measuring the distance between the rocker and the the top of the valve. He Figured it out. Innocent mistake. Welcome to the world of mechanics.

I'd have never guessed that from the pic. He's got the feeler gauge right where it should be. He was soooo close. That's a pretty good one. Lesson learned I suppose.

I've got one that will make you feel a little better. I was having the universals replaced in my van the other day and the kid pulled it onto the lift(drive on style, not supported under the chassis) and undid the rear universal and just about stopped my heart(surely his too) as the van started rolling toward the front of the lift 5 feet up in the air. Fortunately it had a pretty big lip on the front that kept it from going over. Lesson learned. I bet he doesn't forget to set the brake again.

OakBehringer · « **Reply #21 on:** September 10, 2008, 10:44:43 pm »

Quote from: Canada on September 10, 2008, 08:42:03 pm

He wasn't measuring the gap. He was measuring the distance between the rocker and the the top of the valve. He Figured it out. Innocent mistake. Welcome to the world of mechanics.

Haha! Yup. After the first few responses I was like "HOW COME NO ONE THINKS THIS LOOKS RIDICULOUS?!"

Thanks for putting up with me.

dustyc · « **Reply #22 on:** September 10, 2008, 10:54:10 pm »

There's your answer Fishbulb! I assume you know what I'm talking about since you made it your avatar.

ev0lve · « **Reply #23 on:** September 10, 2008, 11:05:03 pm »

Quote from: dustyc on September 10, 2008, 10:54:10 pm

There's your answer Fishbulb! I assume you know what I'm talking about since you made it your avatar.

Valve adjustment. A joint venture of Matsumura Fishworks and Tamaribuchi Heavy Manufacturing Concern.

Were they in spec? Maybe you should look at my master cylinder misadventures if you'd like company

OakBehringer · « **Reply #24 on:** September 10, 2008, 11:39:00 pm »

HERRRRO! American Investor!

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Author Topic: Valve Clearances - What? Mine are like... a quarter inch? (Read 2908 times)