Backfiring causes?

[Skateguy50]

Yes I may borrow a 2.30 temporarily but I'll probably buy one just so I always have it. I will be joining the valve shim club too, and probably soon - all the cool kids are doing it.

If you send Rose over to operate the shotgun for 'troubleshooting' do I get some kind of kevlar suit? I'd probably need it even if I operated it.

sent you a pm, let me know. you wont need to keep one later on cause once your in spec after the long wait if you keep up on it you should only be going 1 size at a time and your other method would be just fine.

[Allie]

The results are in: with the exhaust cam off the cylinder holds air pretty darned well. Time to change out some shims! I'm fairly confident that I can have this thing running again within a couple weeks. I guess it looks as though Dan, who's not even a member, is the winner of fresh pie for his leak down test. Well I can't promise to ship a pie to everyone that's helped me (how do you ship a pie anyway??) but anyone that passes through Jersey will sure get one. Of course I may hit other snags before this is done, but I think the big mystery is solved.

I don't know Rose, maybe you have the whole menacing thing down better than me. I'll let you wave the shotgun.

'48, the moral of the story is DO check those valves, it's not optional! I was skeered to check them too, but ya gotta. If Allie had checked her valves early, this would not have happened. I will also preach that in the repair manual is mentions doing a compression test with every tune-up, and now I'm a believer - it's like checking blood pressure! It's so easy to do too, and it really will keep an eye on your vital functions. By the way Basscleff's valve tutorial is wonderful and it's really not that difficult with his help. I didn't do anything wrong there, again all my problems I'm pretty sure came from not checking them sooner.

Skateguy i will be returning your generous pm, thank you.

[1948man]

Okay, I'm back on track and I have read thru BassCliff's tutorial several times and printed a few pics from it. I hope your 750 sings after the new shims. Jim M

[Buffalo Bill]

Case closed!

Hey Allie, glad to hear you pulled that gunsel out from the inky black shadows and put him behind bars!
That Dan's great, good for you for recognizing his leak down test and adapting it.
Bill
I'll be makin' myself a peach pie this afternoon from peaches a friend gave me.

[Skateguy50]

2.30 measuring shim is on its way, did regular post as its not that far away, suspect you get it Thursday or Friday. Might look funny though, wrapped it in oily paper towels and then duct tape, and put in a padded envelope... not really sure how you are supposed to pack them but it should do.

Don't worry about the pie either, I have more fun making them with the kids than eating them. You could maybe include a recipe or two with the shims when your done.

[themess]

This has been a great technical thread. Lots of conflicting hypotheses, and logic, patiently applied, gradually sorts it all out. Expensive head removal avoided.

When you do your real valve clearance check, be sure that you don't use a Harbor Freight gauge. (I have one that is incorrectly marked.) Use a good one. Snap-On sells a nice one for <$10.

[Skateguy50]

good call, was looking to get a smaller set to check without using the smaller shim now that I am caught up.

Found this one that gets as small as 0.0015" or 0.0381 mm, the regular section didnt have any that small but found this under the diesel engines for governor checks or something... should work though.

http://buy1.snapon.com/catalog/item.asp?item_ID=71&group_ID=1305

My current set think only goes down to .008" or 0.2032 mm, requiring a swap for every check.

[Allie]

I will be getting these for my next valve service, of course they are so tight now that the small shim is a necessity. I've read of the Harbor Fright gauges being suspect, my small ones come from Z1, but only go down to .05. The KD set looks good, especially for $6.

Yes Mess, I did manage to present quite a puzzler for my first real GS question. It feels like a TNG episode, and we finally ended up re-modulating the sub plasmic interphase matrix to accept a negative flow of phions to cause an inverse collapse in the secondary phase of the warp field. Scotty, of course, would have just shoved a wiener in the warp drive (but it canna hold for long!!).

[TheCafeKid]

Realisticly, .05mm is all you need. It's not rocket science and most of us don't have race bikes, so if .05 don't fit, you need to change it to the next shim. The new clearance will be <.10mm. Which is perfectly acceptable if not a slight hair on the loose side. You're not gonna spin a shim out of the bucket. Allie dear when ya get the hang of that damn Zook valve tool, or the zip tie or whatever method you use, a valve adjustment should be an hour job max..

It doesn't need to be made more complicated than it is. And fwiw, head removal isn't expensive, it's time consuming. Own one of these long enough, and the head will have to come off eventually.

[Allie]

Realisticly, .05mm is all you need. It's not rocket science and most of us don't have race bikes, so if .05 don't fit, you need to change it to the next shim. The new clearance will be <.10mm. Which is perfectly acceptable if not a slight hair on the loose side. You're not gonna spin a shim out of the bucket. Allie dear when ya get the hang of that damn Zook valve tool, or the zip tie or whatever method you use, a valve adjustment should be an hour job max..

It doesn't need to be made more complicated than it is. And fwiw, head removal isn't expensive, it's time consuming. Own one of these long enough, and the head will have to come off eventually.

I fully realize that .05 will get me by, but for $6 I will be able to measure down to .02, just because. I didn't think I was making the procedure more complicated than it was. Basscliff's tutorial illustrates just how painless a procedure it really is. My difficulties came solely from not doing it sooner. And Josh dear, as I understand it taking that head off is an automatic $100 for a new head gasket. For me, right now, that's expensive.

[TheCafeKid]

I fully realize that .05 will get me by, but for $6 I will be able to measure down to .02, just because. I didn't think I was making the procedure more complicated than it was. Basscliff's tutorial illustrates just how painless a procedure it really is. My difficulties came solely from not doing it sooner. And Josh dear, as I understand it taking that head off is an automatic $100 for a new head gasket. For me, right now, that's expensive.

Well, $100 for me is expensive I would say too..and my comment wasn't really directed AT you. I was just trying to clear up for anyone else reading and learning from this thread that a top end rebuild isn't always the end of the world. Yeah, it's 3-400 bucks, maybe a lol more or less, but if you do the work yourself, and don't need any serious machine work, depending on the motor (for example, replacing a 1100 motor with another used motor is $500 easy, because that's what the market demands for those motors right now...thanks to those straightliners ) it may be the better option, plus you learn something out of the deal. It's actually pretty fun honestly. I like it a heck of a lot better than "detail" work (rose does that stuff cause she's more patient than I am hehe)

As far as the valve adjustment goes.. I'm not knocking you for using a .02mm feeler, or anything like that. I'm simply saying that if you do the checks as per the manual (every 3000-5000 miles, or basicly every other oil change) and you put miles on your bike like a lot of people, you're looking at three or four valve adjustments a year. Now, once you get yours all in spec, you may find you have to change only three or one or no shims.. But I simply said what I said to make it as quick and painless as possible. And if you haven't gotten one from him already, Steve's excel spreadsheet makes things even faster because it will keep track of what you have in the bike, what your clearances are and were, and the next suggested shim size. Easy least lemon squeezy

Waiting on valve cover gaskets sucks though

[DanTheMan]

Waiting on valve cover gaskets sucks though

RealGasket fixes that problem......

[Allie]

I can get behind all of that Josh. Lemons and all :P.

So yes I did order the standard gasket, from CRC2 I believe. It was cheap and fast, and at the time I didn't think I had time to look into a real gasket, which will likely be my final gasket choice.

Just out of curiosity, how long on average would the OE style gasket last before it's toast? Would it possibly survive one or two valve checks, or would a couple thousand miles toast it? I have this 'thing' about gaskets, I like to reuse them. Too bad it never works out that way.... When I did my carbs I got all of the gaskets off in one piece, except one - and I happened to have one spare bowl gasket. "Perfect," I thought, "I can reuse those three, noooooooooo problem!" Then I breathed on one and practically turned into dust - yes I was silly. I must say though the points cover gasket is doing just fine.

[Buffalo Bill]

This, I've been looking for…

RealGasket fixes that problem......

Dan you have to follow through with more info.

http://www.realgaskets.com/

[DanTheMan]

Thanks, Bill. My Vesrah OEM style gasket lasted through installation and one more time of cover removal sort of. It started seeping, then leaking real bad, I thought I had a new leak from the head gasket area, and it was the cover gasket. Replaced with Real Gasket, cover's been off three times since, no leaks. So far, the Vesrah head gasket (with o-rings I found in my o-ring kit to make up for the missing ones) is still sealing like it should (knock on wood). My bike quit emulating Hardleys, no longer marks its territory.....