help with valves

[bkuhr]

83 xvz-1200 replaced head gaskets due to low compression #2 & #3

 

q1, reinstalling cams,

 

rear head #1 tdc#1 with small holes on edge of cam rail up, lines with cam cap mark. #1 I&E lobes up and face toward each other at about 45deg.

 

front head #2 tdc#2 with large holes on edge of cam rail up, lines with cam cap mark.

#2 I&E lobes up and face away from each other at about 45deg.

 

does not appear both setups are correct. should the large holes be the ones in the end of the cam on front head?

 

q2, still low compression #2, checked valve shim gap, believe problem, valves to tight in #2, including all measurments

compression #1=120, #2=90, #3=90, #4=120

all measurments L-R, T-B looking at each exhaust side

 

rear head #1

#1 #3

current shim I 270 275 278 272

gap mm I .102 .102 .102 .152

rounded shim I 270 275 280 270

sugg new shim I 265 270 275 ok

 

current shim E 278 272 272 272

gap mm E .127 .151 .051 .152

rounded shim E 280 270 270 270

sugg new shim E 275 265 255 265

 

front head #2 & #4

#4 #2

current shim I 275 275 270 270

gap mm I .127 .102 .025 .102

rounded shim I 275 275 270 270

sugg new shim I ok 270 260 265

 

current shim E 268 268 270 270

gap mm E .178 .152 .127 .127

rounded shim E 270 270 270 270

sugg new shim E ok 265 265 265

 

I believe red shims are to tight and opening to soon, blowing some of the compression.

Is it agreed?

 

Have I figured suggested new shims correctly?

 

Where can I get new shims and shim adjusting tool, think I figured out shim tool locks around cam like an open end wrench, swinging around to edge of lifters, pushing lifters down, allowing shims to be pried out. Is this correct? I may make a tool.

 

Thanks for any and all info.

 

Brian

[dingy]

Below is a link to an excel spreadsheet I made to help in picking shims.

 

http://www.venturerider.org/forum/showthread.php?t=43410

 

Gary

[MiCarl]

You can get shims and the tool from this guy - http://www.venturerider.org/forum/showthread.php?t=43412

 

(shameless plug)

[BradT]

q1, reinstalling cams,

 

rear head #1 tdc#1 with small holes on edge of cam rail up, lines with cam cap mark. #1 I&E lobes up and face toward each other at about 45deg.

 

front head #2 tdc#2 with large holes on edge of cam rail up, lines with cam cap mark.

#2 I&E lobes up and face away from each other at about 45deg.

 

does not appear both setups are correct. should the large holes be the ones in the end of the cam on front head?

 

You have it correct that the Small hole line up on the rear cylinders and the large holes for the front Cylinders. I can not remember how the cam lobes faced but it did look ackward.

 

When reinstalling chain tensioner on the rear before attempting to install the front cams it will rotate the engine back away from the T1 Mark. Rotate the engine back to the T1 mark and then Remember to rotate the crank one full turn then an additional 70 degrees before lining up the T2 mark. Then line up the large holes.

 

Careful to get the large and small holes correct. See pic as on one of the cams there was both large and small holes very close.

 

 

Brad

[bkuhr]

dingy, great spreadsheet, like seeing final expected value, and only changed a couple of my calculated needed shims (due to common size rounding error from manual)

 

next question, what size are these shims, 28mm or 29mm for the 83 xvz-1200

 

brian

 

seems after more research these are 25mm

Edited March 23, 2010 by bkuhr
add info

[dingy]

25 mm

 

Gary

[warthogcrewchief]

From what I've seen, usually the piston rings and cylinder walls are what causes low compression - requiring rings and cylinder wall honing. Hopefully it was just the head gasket. Occasionally, a stuck valve or a leaking valve seat could cause a leaking cylinder. Did you clean up the valve seats when you had the head off?

[bkuhr]

ok, been a while, been busy

here's update.

did leakdown, cyl #2 and #3 failed, bad shim gap

got shims from dingy, and bought some

 

heads currently at machine shop for valve job, they also setting shims

if they end up regrinding valves, probably shims I got will be wrong

 

Dingy-you get all shims I can get back from shop, hopefully they will help someone else

 

made leakdown adapter from 1/4 steel plate-rubber gasket,bolted directly on top of cylinder

tested 2 cylinders so far, #1 and #3

-applied 30psi, maintained 26 psi in cyl#1 with rest heard blowing into case (past rings)

consider cyl 1 ok as previously has 130psi compression check

-applied 30 psi, maintained 24 psi in cyl #3 with rest blowing past rings, previous 50 psi compression test

 

what do we think, is cylinder #3 rings servicable, or do we need to start thinking about splitting the case for ring job, or getting another motor

 

still to test cyl #2 and #4

 

all comments appreaciated

Brian

[BradT]

what do we think, is cylinder #3 rings servicable, or do we need to start thinking about splitting the case for ring job, or getting another motor

Brian

 

You should not have to split the case. The cylinders are part of the lower engine casting.

 

Flip the motor on its side, unbolt the oil pan, remove the oil pump and filter and you can get at the bottom of the Connecting rods.

 

You will need a long extension and a swivel. Then push the piston up and out of the cylinder.

 

If the heads are off it is a simple job, 15-30 minutes and all four pistons will be out. Recommend doing all four not just one.

 

Brad

[bkuhr]

talked to machine shop, 1 bent exhaust valve.

anyone know where to get one by monday?

 

pn# 26h-12121-00-00 replaced by 26h-12121-11-00

 

brian

[dingy]

I have a used set, came out of a 1988 engine. 22,000 miles on it.

 

I could overnight you an exhaust valve if you were to replace it and pay shipping of it.

 

It would get you one by Monday.

 

Be $15.00 shipping. I could send it out tomorrow.

 

Gary

[dingy]

I also have a set of extra set of Vmax valve springs.

 

It would give you a higher redline Rpm's

 

$20 plus shipping.

 

Gary

[bkuhr]

dingy, thanks

pm sent

 

are these springs really necessary, shop already has 1 head back together, and other waiting on the new valve

[dingy]

Not necessary at all.

 

Just mentioned it in case you were interested.

 

Gary

[bkuhr]

Dingy

$ sent

 

Thanks Brian

[dingy]

I will get it to post office in morning.

 

I am sending two exhaust and two intake valves. Just in case something shows up.

 

Glass beaded all of them.

 

Return extras. I am in no hurry at all for these back.

 

Gary

[bkuhr]

heads back from machine shop, sure are pretty

heads installed, and valve shim done, all gaps in range

dingy, will send when i get new valve from dealer tomorrow?

redid leakdown with heads installed, same as leakdown directly on cylinders.=no leak in heads or head gaskets

 

new compression test, 1,3,4=180psi, 2=150psi

 

what do we think, wish all 4 matched, but 150psi is still respectable, rather not tear down again for ring job, but rather not put back in bike if this will cause big problem.

this is the cylinder that orginally was not running, and had bent valve, maybe rings will wear in with real compression-wishfull thinking?, no visable damage or scratches on cylinder walls.

 

any thoughts?

 

brian

[Squidley]

Usually your compression test should be within 10% from highest to lowest. Your highest being 180 and lowest being 150 30 lb difference is almost 20%. It's a crapshoot now, 150 is decent compression, but Murphys Law can always rear it's head. What kind of miles are on the bike and how long do you think your going to try and keep it....

[bkuhr]

only 46,000 miles but very poorly kept up by previous owners, have xj750 but wanted bigger 'touring' bike for years, got this 83 cheap, plan on fixing to near orginal and keeping. right now its in so many pieces i hope i remember how to put it back together

[Squidley]

only 46,000 miles but very poorly kept up by previous owners, have xj750 but wanted bigger 'touring' bike for years, got this 83 cheap, plan on fixing to near orginal and keeping. right now its in so many pieces i hope i remember how to put it back together

 

 

 

Put it back together and ride it, when it starts to show it's age further strip it to the frame and redo it if you'd like. The '83's were prone to frame failure by the centerstand and 2nd gear could become an issue. Get a few seasons out of it and then I'd probably think about doing a restore

[Squeeze]

Probably some Ring Free will give you the Compression back your missing now.

[bkuhr]

stripped to frame, frame solid, second gear done do to 3rd gear, guy have been riding with no rear brake master installed=only left front brake, and admitting slamming into gears to down shift, and had knocked pin out of third.

 

rear master placed, brakes done, massive electrical problems fixed, except unknown status of generator, clutch discks replaced, factory oil control mod on stator done, now heads done, carbs rebuilt, needs tires soon,etc, starter rebuilt, and dingy mod-but little different

 

my new money pit

 

brian