The International CBX Owners Association

o.k. boys and girls! here we go.

my motor is out and up on the engine stand as described above. all going well however i have a few questions and am looking for some opinions on whats going on right now. these points are in no particular order:

FIRST IS THE MAJOR ONE THAT HAS ME WORRIED. WHEN I ROTATED THE MOTOR 90 DEG TO THE LEFT ON THE STAND I NOTICED ON THE GROUND A SMALL CYLINDRICAL PIECE ON THE GARAGE FLOOR. IT APPEARS TO HAVE FALLEN OUT OF SOMEWHERE WHEN I ROTATED THE MOTOR. THE VALVE COVER AND THE OILPAN WERE BOTH REMOVED FROM THE MOTOR WHEN I ROTATED IT. I HAD PREVIOUSLY ROTATED IT 90 DEG TO THE RIGHT AS WELL WITH NO ISSUES. I DON'T THINK IT CAME OUT OF THE CASE AND MAYBE IT CAME OFF THE TOP OF THE HEAD BUT EVERTHING APPEARS TO BE AS IT SHOULD AND CAN'T SEE WHERE IT MIGHT GO? THERE ARE 2 HOLES IN THE HEAD CASTING ON THE BACK EDGE OF THE HEAD WHERE THE VALVE COVER SURFACE MATES TO THE HEAD BUT I DON'T THINK IT CAME OUT OF THERE. IT LOOKS LIKE A LOCATING DOWEL AND IS APPROX 3/8" OD AND 5/16" TALL AND IS A CYLINDER. ANYBODY HAVE ANY IDEA WHERE THIS MAY HAVE FALLEN OUT OF????

second, here is what i found for compression. when i bought the bike not running the compression was (from left/shifter side to right/throttle side) in lbs, 115 122 115 132 133 105. after i got it running for a while and tested it again i had the following, 150 140 135 140 150 150. so i think the compression is good.

checked valve clearances today and the are all within the .06-.13MM except the following, number 1 exhaust valves were .26MM and .20MM and the cam caps above that cylinder were a black color, almost like someone had painted them or they were burnt sort of. all other caps were a nice clean alum look. number 2 exhaust had one valve at .14MM and the other at .09MM and number 1 intake had one valve at .13MM and the other valve at .11MM. so it looks like i will need to do 4 new shims. the number 1 exhaust readings make me a little nervous however the valve train appears to be working fine when you put a wrench on the crank and rotate, clockwise of course.

pulled the oilpan off. all looks good in the internals, visually anyway. no broken teeth on gear clusters etc. found some sludge in the oilpan AND some pieces that look like parts of a plastic or alum. o-ring or washer of some sort?? other wise when i looked into the case with a flashlite and turned the crank everything looked pretty good. i don't want to split the case or pull the head and cylinder but just make sure everything appears to be in tact.

when i pulled the carb boots of they are the boots for a 79/80 model (straight) so i will need to by some angled boots as my bike is an 81. i am guessing randakks or tims is the place to go for these.

the neutral switch is really rusted at the connection but working properly, i probably will replace to be safe.

i have one small dent in the left side crank cover and am planning on having these chromed so i will try to source a used one in good shape.

if i wanted to remove the alternator and unbolt it from the case does it come off in one nice peice or will i have a pile of springs or bearings etc. to cotend with? what about just removing the magensium cover off the alternator for polishing? when you remove either the cover or the alternator body does it come off in one part? the rubber boot where my wiring enters the alternator is ripped bad and i am concerned about water ingress.

same question as above for the clutch cover and the pulse generator? do you remove it all as one piece by removing the clutch cover or do remove the pulse generator first? really just want to get into where the clutch is and not mess with the pulse generator.

how does the oilpan screen come off for cleaning? it looks like it should just pull off but it wasn't budging and i didn't want to force it. it will spin where it's mounted but it won't pull off?

what about oil cooling. is there an aftermarket (larger) oil cooler or do you think one of "tims" deepsump oil pans would help cooling?

getting close guys

will a set of 82 carbs and brackets fit directly onto my 81?

i am pretty sure i have the 79/80/81 petcock on my tank however when i removed the petcock it came out with just the brass tube, no screen. it looks like the screen is still stuck up in the gas tank. should i just try to rip it out of there and replace the whole pertcock? also didn't see the o-ring for sealing the petcock to the tank?

as i mentioned before, i am pretty sure i bought somebody elses project so i am sure i will be un-doing some of there work. carb boots for example.

any thoughts would be much appreciated. and thanks for taking the time to read this long post :)

thanks!
kent

kbart1 wrote:thanks guys

all mounted up to the engine stand bracket now. just need to find half a dozen freinds to come over and help me lift this 238 pound behemoth onto the stand. any of you guys live in vancouver

kent

When I was mid stride of my build I had a triple hernia operation and wanted to get my engine back in my
bike . . . . . . Two strong friends can do the job for ya !




Bob

kbart1 wrote:if i wanted to remove the alternator and unbolt it from the case does it come off in one nice peice or will i have a pile of springs or bearings etc. to cotend with?

The alternator has the 6 bolts that you see. Three of those hold it together and the other three hold it to the engine - To remove it as a whole unit, you just take out the longer three and it will come off in your hand. Unplug the cord first

what about just removing the magensium cover off the alternator for polishing? when you remove either the cover or the alternator body does it come off in one part? the rubber boot where my wiring enters the alternator is ripped bad and i am concerned about water ingress

To remove the cover, after you have the unit off the bike, remove the other 3 bolts and it will come apart. Only the '79's had magnesium covers and those can't be chromed or polished, but since you have an '81, yours should be aluminum and will polish up fine. The rubber wire cover is NLA from Honda but they have been reproduced. You occassionally find them on eBay and Tims sells them as well as Six Center in Holland - About $25 or $30 I think

what about oil cooling. is there an aftermarket (larger) oil cooler or do you think one of "tims" deepsump oil pans would help cooling?

The '81 already has a larger cooler - 7 rows VS the 5 that the '79 came with. You can install an Earl's aftermarket cooler which is much larger than stock. I have a 10 row on mine and you can also fit a 13 row Earl's - $150 or a little more for the cooler and associated parts to mount it and hook it to the oil lines

Don

great! thanks a lot don!

That's what friends and beer are for!! Cool

thanks for the info guys! any thoughts on that liitle cylinder or dowel that fell from the motor. gotta go watch the canucks beat san jose now!!!

kent

sorry guys. i'm working on an '81 not '79. :)

thanks
kent

Thanks, Don for that excellent response. As to the 'cylinder' that fell out - is it hollow or solid? There are lots of locating dowels, but none should fall out if you don't have the cams removed. Seems like it was laying in the sump and fell out when you rotated the engine. A pic would be great. Seems like it might be one of the two locating dowels for the clutch cover - they are the smallest ones.

Dave

hey dave

the little dowel is hollow and it is about 3/8" OD and about 5/16" tall. it may very well have been resting in the sump and when i rotated it fell out? just found it on the floor after rotating the engine 90 degs to the left. cams not touched, no internals messed with. just checking valve clearences and looking around for any concerning items. i need to get going with posting photos, not REAL handy with computors but i'll get it figured out :)

thanks!
kent

A few questions were not addressed:

kbart1 wrote: the cam caps above that cylinder were a black color, almost like someone had painted them or they were burnt sort of.

Take the discolored cam caps off and check for scoring, which would indicate any problems.

do you remove it all as one piece by removing the clutch cover or do remove the pulse generator first? really just want to get into where the clutch is and not mess with the pulse generator.

The clutch cover can be removed without removing the pulser generator.

how does the oilpan screen come off for cleaning? it looks like it should just pull off but it wasn't budging and i didn't want to force it. it will spin where it's mounted but it won't pull off?

The screen hardens over time due to the heat cycles and is difficult to r&r. You have to pry it off. You may be better off replacing it with a new one.

will a set of 82 carbs and brackets fit directly onto my 81?

Yes

i am pretty sure i have the 79/80/81 petcock on my tank however when i removed the petcock it came out with just the brass tube, no screen. it looks like the screen is still stuck up in the gas tank. should i just try to rip it out of there and replace the whole pertcock? also didn't see the o-ring for sealing the petcock to the tank?

If i remember right, the screen is being pressed to the tank fitting by the pertcock. It will come off when you pry it carefully. The seal, I think, is between screen and tank

it's a good thing i'm in a good mood this morning!

thanks for the great info guy's. now for the bad news. i did remove the offending cam caps and ouch! number 1 (farthest left on the exhaust cam) is totaly scored up, even chewed off some material from the cap. number 2 cap is bad however no as bad as 1. number 3 cap looks pretty good (to me). i pulled off several of the clean or not discolored caps and they are as smooth as a babys but. so, i appear to have some sort of a problem with the left side exhaust cam bank. i am curious though, i would have thought that there would be a bearing between the cam shaft and the cam cap/head surface? don't these things use removable bearings in those areas? if not and the cap is wrecked then obviously the head surface would be destroyed too? i will obviusly need a new cam? what happens to the head now? i really didn't want to tear down the motor but looks like i've bitten off a large project, here i was hoping it was all cosmetic

also, i removed the alternator in one big peice. i have a couple questions though. firstly when i removed the alternator the was a little what i think is brass solid dowel with a little hole in it "floating" in the shaft. is this some sort of check valve or something for oil control? also the disc of the alternator was wet with oil and it reminded me of kind of a grinding wheel, sort of an oily abrassive finish. there was also a bit of a paste like goo on the case just inside where the alternator fits into, is it residue off the alt. disc possibly?

lastly, tried to remove the clutch cover with pulse generator attached. took out all the bolts except i broke one of the bottom bolts (the bolt that is on the bottom back toward the swingarm, there are 3 in a row there) and now i can't get the cover to budge off the case? i don't want to force it. should it just pull off? perhaps the gasket is holding it together? any ideas how to seperate the housing from the case?

all that being said. i am a little bummed out so i am going to hop on my wing and go for a nice theraputic ride while i ANXIOUSLY await your replies.

i read some where in the forum these wise words "if the person tells you it ran FINE when it was parked BUT" you better be prepared for some surprises!

more to follow, OBVIOUSLY!

thanks
kent

kbart1 wrote:it's a good thing i'm in a good mood this morning!

thanks for the great info guy's. now for the bad news. i did remove the offending cam caps and ouch! number 1 (farthest left on the exhaust cam) is totaly scored up, even chewed off some material from the cap. number 2 cap is bad however no as bad as 1. number 3 cap looks pretty good (to me). i pulled off several of the clean or not discolored caps and they are as smooth as a babys but. so, i appear to have some sort of a problem with the left side exhaust cam bank. i am curious though, i would have thought that there would be a bearing between the cam shaft and the cam cap/head surface? don't these things use removable bearings in those areas? if not and the cap is wrecked then obviously the head surface would be destroyed too? i will obviusly need a new cam? what happens to the head now? i really didn't want to tear down the motor but looks like i've bitten off a large project, here i was hoping it was all cosmetic

Ouch, Kent There are no bearing shells in these cam seats. The head is line bored with the cam caps in place, and when the seats are destroyed, so is the head. My guess is, that someone may have replaced the caps at one time and did not check for proper clearance/play and the seats scored.

tried to remove the clutch cover with pulse generator attached. took out all the bolts except i broke one of the bottom bolts (the bolt that is on the bottom back toward the swingarm, there are 3 in a row there) and now i can't get the cover to budge off the case? i don't want to force it. should it just pull off? perhaps the gasket is holding it together? any ideas how to seperate the housing from the case?

Indeed the cover has a tendency to stick to the housing. There are dowel pins also, which contribute to a tougher removal. Give it a few taps with a rubber mallet. It may budge.

unless i am an idiot no i don't see any bearings in the cam CAPS. unless i cant see the seam etc. but it sure looks like there is no bearing in the CAP. as far as the head surface, i cant tell if there is some sort of a bearing there or not because i haven't removed the camshaft yet. other than caps 1 and 2 all other caps look good, nice and clean and very smooth (bores). if there was a bearing surface missing wouldn't the cams rattle around in there like crazy? other than 1 2 and possibly 3 all cam caps/cam surfaces look great. could it have been an oiling issue to the left exhaust cam bank??? i am pretty handy with tools and getting handier by the day but heres my question. is pulling the top end of this thing a crazy job? the cam chains scare me a bit but iguess once i get past them its pretty straightforward tearing it down. i REALLY don't want to split the case so i am praying the bottom end is good

thanks a lot!
kent

EMS wrote: Ouch, Kent There are no bearing shells in these cam seats. The head is line bored with the cam caps in place, and when the seats are destroyed, so is the head. My guess is, that someone may have replaced the caps at one time and did not check for proper clearance/play and the seats scored.

.

The cams run in the bare aluminum. The same on all early 80 Honda DOHCs. It could be an oil issue, but as I said, it also could be a matter of someone replacing the cam caps, which actually, you can't do without being very careful about it and check the fit with plastigauge.

so bottom line is the cams have to come out. all 4 cams or just the offending bank? remember the other caps i removed looked SWEET. i read somewhere the hot set-up for the '81's was to use '81 exhaust and '79 intake cams? more lift on the '79's i believe. if i'm in there why not.

kent