Did some work on the bike today...valve shim question

Got out to the garage today to start working on the bike and get it ready for this summer. Repaired the #1 spark plug hole with a insert and went through the valves checking clearances and shim sizes...this is what I came up with.

exhaust

250 250 245 255
.152 .127 .152 .127

intake

260 240 260 260
.051 .051 .076 .051

Spark plug insert went better than I thought it would. Packed the tap with grease and ran in and cleaned a few times. Vacuumed out the spark plug hole and pulled the exhaust pipe and sucked out the rest with the exhaust valve open. Any care to take a look at my valve readings to find out what I need to do....I haven't got my manual yet.

 

exhaust shim replacement sizes:
245 245 240 250

intake shim replacement sizes:
250 230 255 250

 

Bleed....

I have ALL of those in my NOS shim pool......PM me.

Dave Fox

 

Thanks MiCarl.

Hoggfiddles, you have a PM.

 

bb,

The valve clearance specs (intake 0.11mm ~ 0.15mm, exhaust 0.16mm ~ 0.20mm) are printed on the label inside the right cover. The replacement shims MiC gave you will put you there. Keep the shims you can use to bring another bucket to specs and use HF's shim pool to swap/purchase the ones you need. Caution: You need to have a shim in each bucket BEFORE you rotate the engine.

Gary

 

Hmm....that could get tricky. May be stupid to ask buy why do you need a shim in to turn the motor? I figure I only need to get a 230, 245, and a 250 and will have 3 260's left over.

 

To eliminate the possibility of damaging the lobes. Tricky? Not at all...you will change one at a time. HF will refund your deposit once he receives the three 260's you'll send back to him. Some members don't swap the shims they won't be needing anymore for the ones they do need. You've got it. Sorry bout' that.

Gary

 

I figured it was something to do with damaging the cam lobes. Might be tricky swapping them around in the right spots without going back over a couple but shouldn't be to bad. #3 and #4 are the worst to do just because you have to reach over the top of the motor to turn the motor over while trying to hold the wire in the chamber holding the valve open. Probably plan on getting the correct tool if I run this thing long enough to do another valve check....maybe just get it before I get the new shims lol.

 

Pm'd back......

Dave F

 

The interval is only 5000 miles. Doesn't take much riding to get there.

 

Yeah I just don't know how long I will hang onto it, depends on how reliable I can keep it for daily use. I guess if I had to do it once a year (over the winter) it wouldn't be to bad. I drive 45 miles per day for work so it would rack up easy in a year. I was used to my Harley, 25k in 3 years and did nothing but oil and tire changes.

 

It's really not that bad once you've one it a couple times.

Even after the first time goes a TON faster, as you should have a record of what size shims are where. Meaning instead of having to pull every shim to see what size to go to, you just have to measure the gap and then figure what shim you need by already knowing what's in there.

As well as there is likely to be less out of spec than the first time you did them - as its a CHECK every 5k, not a guarantee that you'll have to re-shim all 8 valves.

Not a big deal at all imho.

 

and if you need, dave can hook you up with a "placeholder" shim that helps in swapping them all around.

 

As a practical matter at your 5K interval it'll pretty much just be a check. The situation you have is because of a lot of neglected maintenance.

 

Precisely.

 

Seems most shimmed valves require less adjustment as they get older too, the neglected first adjustment is almost always the worst you would come across doing regular maintenance. Next time you might have only 1 or 2 or even none that need adjusting...but still want to check.

 

Well I got all my shims swapped around and did a compression check. #1,#2, and #3 were 145 and #4 was 150. Pulled the carbs to start going though them. #2 carb is really black inside, might have been backfiring thought the carb? It idled and revved pretty well after the valve shim swap but still popped and bogged under acceleration. Going to do a bottom end kit on the carbs and clean the rest. The air/fuel caps are still installed on the carbs so that should be fun. Hopefully that will take care of things and get it running well after a synch. Then onto the brakes and tires and maybe a new updated fuse box.

 

Once you put seriously out-of-spec valves back into spec, you can't expect the original sync adjustment to be anywhere near close.

Don't do just a "bottom end" on the carbs. Those plot air caps need to come out; and the pilot screws will need new o-rings. Honest.

Plus be sure to accurately wet-set the float levels.

It sounds like you're already in a "rush through/skim over" mindset. THAT WON'T WORK.

Do it right; or you'll do it over (and over and over and over) until you do.

 

Yeah, now that the valves are back in spec you should make sure the carbs are 'back in spec' and then get the sync 'back in spec'.

Then you'll have a tiger strapped under your butt.......hang on tight.

Dave

 

By bottom end kit I meant buying new float valves, probably the shaft seals/washers ect ...I think everything else is probably ok (don't know till I get into it). I like to retest things (like running it after the valve shims) to make sure I didn't make something worse than it was. I plan on polishing the throats and such to get the "clunk" and doing a wet set. It may sound like I'm "rushing" though it but it is far from the truth. I'm used to maintaining 30's Fords that my dad and I drive up to 2500-3000 per year and have driven to almost every state east of the Mississippi. Proper maintenance is a neseccity when driving 80+ year old cars, short cuts will only get you in trouble.

 

I may also buy new intakes, the old ones are cracked on the outside but show no cracks on the inside. I already removed them (soaked the bolts every day for a week prior to removal) without any issues. I planned on putting close to $1k in this thing to make it completely reliable for the next few years of riding, which shouldn't be to hard to do.

 

$1k won't be hard at all since you're planning on getting it reliable, but that's still way cheaper than a 'newer' bike with similar capabilities. Your intake rubber can be shored up with a repair, but if it already has cracks that are visible you'd only be prolonging the inevitable-good call to replace. If you can afford it, you should go ahead and do the full monty on the carbs-you will thank yourself later.

I can relate to keeping the old trucks on the road, if you've done that you'll be fine with your MUCH newer XJ. BTW those are nice compression numbers, in spec and close to each other=good. The black might be exhaust escaping back past the valve, but it could also be overfilled oil that got sucked in through the breather and just sat when the PO couldn't figure it out. Keep up the good work.