cam shaft oil starvation

[bluemouse1006]

Hi

Well started my bike for the first time after about 2 months, Ive stripped the engine replaced all seals and gaskets etc, replaced inlet valves also after finding they were bent !!
I've looked on this forum and was paranoid about all sorts of stuff so after about 5 minutes of the engine running I removed the tappet adjust covers and looked inside,seems 1+2 cylinder has oil around the base of the valve springs,took 3+4 off and they are totally dry. May be me but I thought that because that the bike was on its side stand the oil might have gone to one side
But to be honest think that I may be fooling myself !!!!
I remember when fitting the cam carrier there was two oil ways coming from the centre head bolt which had o rings around them and another two oil ways in the head that didn't have holes in them but strangely still had O rings is that normal ?
Think I will have to take the engine out again (third time !!!!!!!!!!!!) and have a look at the oil ways to the cam shaft, anyone have any ideas/photos about what I should be looking for.

Although its dry on one side I do feel lucky that I haven't ridden it and snapped the camshaft and made even more work/cost for me..

would really love to hear your comments, I've got tomorrow off so will be stripping it again then if needed !!

Thanks

Amos 
 

[Bryanj]

Did you remove and clean the restrictor jets under the cam carriers?

[bluemouse1006]

Hi

Thanks for the reply No I cant remember doing that, will be removing the engine today and have a look at that. and let you know how I get on

Amos

[Bitsa (Ralph Wright - RIP)]

Hi.
Under the cam carrier there should be 4 little o rings even though there is no hole for 2 this I believe is to keep the pressure up by sealing between the carrier and head.The oil comes out through the re stricter and then travels through the cam carrier and squirts out at pressure over the cam etc.Blow out the cam carriers with air.Did you use gasket goo?Too much can block the oil coming up the main oil studs.Hope this helps.
All the best

[bluemouse1006]

Thanks for all your comments

Stripped the engine today and checked out the head oil restrictors and guess what the dry side was partially  blocked with what looked  like paint flecks, lesson to be learnt don't paint the engine casings and paint the inside with engine  paint or should i say over spray anyway .

I also decided to whip the sump off and check that and again loads of flecks of paint and some what looked like cleaning rag material this was partially blocking the oil pump filter !!!!  glad I stripped it as it could have happened again with the dry head Like playing Russian roulette with the engine ..

I still have to put fresh oil and another filter and hope that the oil gets up there but very very happy I actually found something after a days work .

Ill keep you all up[dated when I get her started again

Thanks again

Amos

[the-chauffeur]

Mouse

Been there, done that - the blocked oilway on one side, that is.  Expensive problem if you don't catch it early . . .

Long story short, I trashed a camshaft because of a blockage in the right oilway.  After some investigation, and much to my surprise, the blockage wasn't in the jet in the head, but was much lower down the engine - it was in the top of the crankcase.  My advice would be don't even think of starting the engine again until you've been able to pump some oil through the engine manually and can watch it flow out the top end.  This is easier said than done unless you've got some way of holding the engine still with the rocker cover off (and preferably with the camshaft/rocker assembly off as well). 

I fitted a kit to the frame of my '72 that allows me to remove the top of the engine while it's in the frame.  When it came to second/third reassembly, I was able to leave the cam train parts off the top, fill the bottom end with oil and then crank the engine using the kick start (which engages the oil pump).  It took a good few pumps, but after a while oil came flowing out the jets, and I only reinstalled the camshaft/towers when I was sure there was a good supply to both sides.

And yeah, you need all four O-rings under the cam towers - the outer ones may sit in blind holes, but they seal the join between the cylinder head and the underside of the towers, which in turn creates the pressure needed to force oil to spray around the top end from tiny oilways in the tops of the towers.  Having said that, be aware that there are two different sizes of O-rings; the bikes up to and including early K2's (I think) had fixed oil jets in the head, and use smaller O-rings than those used on the later K models (which have removable jets).  Check your parts carefully.  You might also want to take a look at Hondaman's guide to modifying the cam towers for better oiling.

I've also found rag bits in my filter in the past.  Mine were bits of polishing mops left over from when my polisher had shined up the engine sidecovers but didn't clean them out when he'd finished. 

Hope that helps.

[bluemouse1006]

Hey Thanks

Ive the engine back in now with the rockercover on,as you say it would have been better to check for oil before hand but I was happy I found enough restriction to cause the fault  (there was a little oil getting through. the other link was very good but has made me nervous now about every thing seizing in the future,Im running the bike this summer and will be changing the camchain etc in the winter if the rattle that they all have annoys me enough ..

Thanks again and Ill keep you updated

Amos

[K2-K6]

It's really easy to turn these over with the starter motor when out of the frame so you can check oil supply with cam cover off before install.

If you cut the right shape whole in a piece of 3/4 inch plywood. and fix it onto blocks, you can get the engine to stand quite firmly in it. Can be useful when assembling the top-end anyway.

As an interesting point, I've always turned these motors over by hand for the first time after fitting cam etc as you can feel if anything is wrong (I've seen many times bent valve from others using the kickstart or electric) one or two rotations then double check the cam timing before going further.

Hope youv'e got the oil supply sorted now.

[bluemouse1006]

Hi

As you can see from my clutch horror story on the other post I have the engine running and seem to have a good oil supply to the top end now just wished the clutch would clear!!
Im going to keep an eye on it just in case. thanks for your help and comments

Amos

[ChrisD]

Hello.

Yep can identify with the previous posts, rebuild my K0 in 88 and used to much gasket goo on the cases which got up to the cam carriers and yep blocked the restrictors and blew away a cam and followers, took out the engine and cleaned it all up but this time made sure had good flow by connecting up oil tank and mounting the engine on a dexion frame and turned it over untill oil flowed well to the top end. Refitted and and its still oiling ok. In process of rebuilding bike back to original colour so will have engine apart again to renew primarys and cam chain and anything else that looks suspect.

Cheers all Chris.

[K2-K6]

Welcome ChrisD and interesting addition to the experience.

It's something that can affect all of them on the site in that the cases of these are, if in good order, very easy to seal when rebuilding.

BUT, and it's a big one, they need a VEEEEERRRY small amount of sealant to do that really well and the risk (as many have found) is that too much causes much more of a problem than the risk of a small oil leak which is fixable with labour, unlike a trashed top-end.

Boringly!! I've always used Blue Hylomar for this without any problems, with the joint surfaces cleaned and dry (wiped with alcohol) you can put just a very thin smear on and let it dry before assembly. If you have to strip it in tghe future you find all but nothing squeezed out of the joint, so nothing gets to travel around the motor.

[ChrisD]

Hi top end fixer and cheers for the welcome, yep did use blue holymer on the 88 rebuild and yep plastered it on, so goes to prove to much is not always the best?. Just in process now of getting carbs sorted and came across a few bits in the rebuild kits that are of no use to my beast, namely the air screws that have holes in them and the bike would not idle, so brought a ultrasonic cleaner and cleaned up all the carbs and refitted the old air screws and bingo more or less a perfect idle staright away. Just got to sync them up and hopefully smoothnerss will return (do get a slight pop from No2 pot but it seems to have always done that).

Cheers Chris.

[K2-K6]

Yes thinking of the logic of it now the cases bolt up in an all-but metal to metal contact to maintain the tolerance of the main crank bearings, so if you succeeded in keeping much joint sealer in the gap the bearings would probably suffer.

I've taken apart stuff for other people in which the oil puck-up has been all but covered with bits of silicone and similar, guess that's another way of killing the oil supply to critical parts.

They really do survive on good oil distribution and will really go to quite high mileage if kept in good order.

Be interested to see some pics of your K0 when you've got through the refresh/build.

[Bryanj]

All I can say is that back in the 70's when i worked for a small independant dealer(now a big Kawasaki dealer) we actually kept as spares on the shelf cam, cam towers and rockers due to the number of locals with 750's that pulled them for non existant gearbox trouble and buggered up the cam with gasket goo of a myriad of colours.

We even had a machinist who would spend the time to grind the cam bearings and bore out the towers then make split phosphour bronze bushes pegged in (as long as the lobes were OK). From memory charged about 70% of new parts cost

[Seamus]

Using sealant on the pucks is not unusual. It is recommended by Hondaman in his book on 750's, but not too many other places. Also the recommended sealant is Hondabond or yamabond (also threebond)