Beans dont burn on the grill, but did my valves???

[Guest]

I was checking my clearances on that motor i picked up off ebay. Intake side was all tight, so tight in fact the only one i could get into spec (due to the shims i had available at the time) went from a 2.80 to a 2.65. Exhaust were all within spec save for one, and i had the shim to fix that. Anyway, with all those intake valves being that far out of spec, it makes me worry about burnt intake valves. I looked down thru the plug hole to see what i could see of the intake valve and it didnt look cooked, the piston crowns are all a lil bit carboned but thats to be expected, especially considering based on the look of the plugs i pulled out of it and the smell of what oil was left in it, it had been running rich.

Here's my question, is there a way with the motor out of the bike, and NOT pulling the head, to tell if the intake valves are cooked?

[Nessism]

Can you hook up a starter and run a compression check? 265 is not too thin by the way so you might be okay.

[TheCafeKid]

I know its not thin, but to have to drop that many sizes worries me. thats 3 sizes from where it was. woundnt that be leaving that valve hanging out there pretty good? You'll have to pardon me, i am still grasping the concept of some of this valve train stuff.

[salty_monk]

You'll probably be ok. It's normally exhausts that burn first & then only when a valve is held open so you get blow-by.... You need to do a compression test. Harbour freight has some cheap ones if you haven't got one.

Dan

[TheCafeKid]

I have a compression tester, i DONT have a leakdown tester tho. And damn they are kinda pricey (at least for me right now)

Ok so if my fuzzy math is right i went from 2.80 to 2.65 before i could get .04 feeler in. so that means i was anywhere from .11 to .10 out of spec?

[dardoonk]

Beans dont burn on the grill....

Fish don't fry in the kitchen,
Beans don't burn on the grill.
Took a whole lotta tryin'
Just to get up that hill.

Now we're up in the big leagues,
Gettin' our turn at bat!
As long as we live,
It's you and me, baby!
There ain't nothin' wrong with that!

Hooray, We're Movin' on Up! ..Movin' on Up!
To the east side!.. Movin' on Up!
To a dee-lux apartment in the sky!


Sorry, I could't resist....

[BassCliff]

More shims please!

Mr. TCK,

All I know to do is to put in the shims you need to get the clearances in spec. It would be really handy if you could borrow a full set and then just replace the ones you use. Is there anyone close to you with a full set (or at least a large number of varied sizes)? ;-)

Maybe a shop will let you "borrow" a larger collection of different sizes if you leave a credit card for collateral? Then you can purchase just the ones you used in your motor when you bring back the set of shims.

Then run the motor and/or test the compression. I'm sorry to hear this is turning into such a hassle. It really shouldn't be this hard.

Thank you for your indulgence,

BassCliff

[TheCafeKid]

Mr. TCK,

All I know to do is to put in the shims you need to get the clearances in spec. It would be really handy if you could borrow a full set and then just replace the ones you use. Is there anyone close to you with a full set (or at least a large number of varied sizes)? ;-)

Maybe a shop will let you "borrow" a larger collection of different sizes if you leave a credit card for collateral? Then you can purchase just the ones you used in your motor when you bring back the set of shims.

Then run the motor and/or test the compression. I'm sorry to hear this is turning into such a hassle. It really shouldn't be this hard.

Thank you for your indulgence,

BassCliff

I appreciate it Cliff. It really isnt this hard. Steve taught me how to do it, and it really is simple, i dont want anyone reading this who hasnt attempted it thinking its normally this difficult. Its just apparent that at least the intake side of this motor hasnt had any attention to the valves in a while. I'll be ok. Yeah i was a little freaked out, but as Kurt has put into perspective. There are/have been probably thousands of these bikes running around with their valves too tight for a while, and they keep going. So with any luck, my valves arent cooked, and we'll be ok. The bonus is, i do have another motor that i KNOW the valves are in spec on, and it runs too. So if i DO have to tear this thing down, at least i wont be rideless.

[BassCliff]

A shim! A shim! My kingdom for a shim!

I appreciate it Cliff. It really isnt this hard. Steve taught me how to do it, and it really is simple, i dont want anyone reading this who hasnt attempted it thinking its normally this difficult. Its just apparent that at least the intake side of this motor hasnt had any attention to the valves in a while. I'll be ok. Yeah i was a little freaked out, but as Kurt has put into perspective. There are/have been probably thousands of these bikes running around with their valves too tight for a while, and they keep going.

You are correct, Mr. TCK. It's not difficult and I'm not impugning your mechanical skills. It does get a little tricky trying to figure out exactly what size shims you may need if the adjustment hasn't been made in quite a while and the valves have been running overly tight for a lot of miles.

I'm lucky there is a generous GS'er near me who lets me borrow a well-stocked shim kit (thanks Ms. SqDancerLynn1!) and then I just replace the shims I use. I'm able to try several sizes to dial in the optimal clearances. I like keeping them on the loose side of the range if I can.

I wish you happy wrenching!

Thank you for your indulgence,

BassCliff

[chef1366]

Dig in, take a look and learn.
Don't be afraid cause gaskets are cheap and knowledge is priceless. \\/

[SqDancerLynn1]

Intakes don't get as hot as exhaust shouldn't burn. Just get them adjusted & forget about it.

[Ludeykrus]

I gotta agree, you shouldn't worry over running an intake valve off for a while. Exhausts will cook first and easiest.

That being said, if you REALLY wanna check to see if you have something major to worry about and don't have the full leakdown tester, try this:

Turn the first cylinder over to TDC to close all the valves. Take the hose from your compression tester and screw it into the spark plug hole. Attach it to the quick-connect on a hose running from an air tank or air compressor. Now, if you have any major leakage from an intake valve on that cylinder, you will hear a good leak/whistle from the carbs/airbox. If it's an exhaust valve, you can hear it from the exhaust pipes.

Happy wrenching!

[Suzuki_Don]

Josh. Try this link for a leak down tester.

http://www.mediafire.com/?elwnncxmgma

Cheers
Don

[bwringer]

I doubt very much that there's a problem, but I bet the engine was running like absolute dog crap and someone (you?) was wondering why the heck the thing wouldn't get out of its own way. Out of spec valves really screw up carburetion.

If they're in spec now, don't worry about it, even if it did take moving two or three shim sizes.

If you have a burned valve, you can't get the correct clearance even with the smallest shim (2.15mm). Guess how I learned this...

And anyway, it's extremely unlikely that it would even be possible to burn a GS intake valve. Someone's probably managed it on a 16V engine, but I don't see how on an 8 valve engine.

[TheCafeKid]

Thanks for weighing in on this Brian As of now, im one for four in getting them in spec. Im waiting on some shims, hopefully with which i can correct this problem. Thankfully the exhaust were all but one in spec, and the one that wasnt was one shim away, no craziness there. All in all this motor looks really good. As i said it had some gassy smelling oil in it, and the plugs were blackened, which if the intake valves werent closing, theres the reason for that i'd say. the cams look good, no scoring or even real signs of wear, which, if this motor has as few miles as the PO said it does on it, should be expected had it been resonably maintained. I just wonder why the intake was sooo far out like that? Ah well, if i get em in spec, why ask why?