Topic: HEEEEELP! No oil to No 1 and 2 Tappets

[Steelo]

Pulled engine out of bike and removed rocker cover - easy peasy other than a few screws deciding to be obstinant. Took off rocker cover and found tappets and head area of No 1 and 2 bone dry. 3 and 4 were well covered in oil. Tappets 1 and 2 don't move when the engine is turned over using kick starter. The camshaft holder cap at No 1 was cracked and fell off when the bolts were removed. The shaft end is stuffed - totally scored and bits of loose metal.
Also camshaft for No. 3 and 4 turns and on the No. 1 and 2 side it doesnt move LOL "I think this is important"!! lol without totally removing the camshaft yet I'd say the shaft has snapped or sheared.
Where do I go from here?
What would be stopping the oil getting to tappets 1 and 2 oilers yet 3 and 4 are doing fine?
Will camshafts from all cb 750's swap with K7 one?
Can I just swap out an entire top end e'g. tappets guides and camshaft off another engine if I can find one.
See attached pics.

[oldbiker]

Hi Steelo, I feel for you mate. If you go to (http://www.cb1100f.net/Other/CB900FManual/Honda%201980%20thru%2082%20CB900F%20Service%20Manual%20Chapter%2002%20Lubrication.pdf)
you will find a diagram showing how the oil is circulated in your engine. I hope this will help you to find the blockage which has caused your problem. I cannot advise whether you can change parts because I am a CB400f owner but I hope the diagram is what you need.

[bryanj]

When you lift the cam towers after removing the cam you will find a small restrictor jet in the cylinder head sealed with an o ring I can be 99.9% certain that this jet is blocked. It only takes a minute piece of gasket goo or old gasket or just crap to block this tiny nole. Your best bet ie ebay to get a pair of tower complete with rockers and a cam them keep the one good tower as a spare. NOTE that the bearing caps are stamped and not interchangable.

THIS PROBLEM IS WHY HONDA SPECIFY 10W 40 OIL AND 1500 MILE CHANGES

[ericstew]

HI,

Your engine is the same as the F1.After engine number 2719997,a F2 camshaft was used.
You virtually can use any camsaft and F2 are harder to find(F2 got bigger valves/different valves opening diagram).
The best thing to do is to change the camshaft and its towers.
As Bryanj wrote you,you MUST check that the stamps on each tower are matching or you'll have to change your camshaft again soon!+ he's perfectly right on your oil problem.

[Steelo]

Thanks for the information and advice guys.

Ericstew are you saying only K7 and F1 camshafts are interchangeable or any 750 up to and including the F1 are ok?

Sheesh looks like a 2 hr drive to the big smoke to the wrecker for parts and the "Honda Stealer" for gasket kits (which won't be in stock!!!) and the bolt supplier for allen bolts to replace crosshead screws.

[mutters]

mate, I think with that amount of damage you would be looking to pick up a full set of cam holders and camshaft.
Could find 'em on the ebay.
any full set should be interchangable(??)
 
Also my guru tells me a few of the 750's come through his shop without the oil jets fitted and they run perfectly well with no problems in that area.
I'm not suggesting you remove them though!

[750goes]

I posted on another thread that I was looking at bidding on ebay for a 1978 750F2, but was unsure of engine/frame etc...

Well to cut a long story short, there is another person bidding against me and I have now hit my limit.. for bidding purposes.

It may be that If you were interested in this bike for the parts you need, and if you were interseted in contributing/sharing the costs so to speak, I would like to buy the bike, and I will send you all the bits/pieces you need..like head, cams, i dunno the bits you need..

I can pick up the bike from its location, and store it in my warehouse

You would still need to get your gasket set

If you are interested send me an email with your contact number and I will give you a call to discuss options or parts required.


The link for the item is below

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1&item=4600346905&ssPageName=STRK:MEWA:IT

I'm mainly interested in this bike so I can complete mine to put on the road in reasonable shape (see my bike in photo).

the ebay item ends in 1 day 18 hours

just a thought it may save you a few dollars ??

[ericstew]

Any camshaft from K0 to F1 will do.There are slight differences on opening valves timing but the only way to know which camshaft you got is to measure it!The F2 camshaft is the only one really different.

[ericstew]

 :)Check item #4601594024 on e-bay that's just what you need!

[bryanj]

The other thing i forgot to say was with this problem a COMPLETE engine strip and wash out is called for to remove any floating crud and with this in mind a replacement cam chain with maybe the rollers is a must. I also have heard of missing oil jets BUT in my oppinion this must reduce the oil pressure/flow at the mains and big ends which is not, to me, a good idea

[eurban]

As to camshaft differences, from what i read the 75 and 76 F models and the 77 and 78 Ks got a slightly hotter camshaft than the mid production year 750s. Don't know about the earliest cams.  If this matters to you then keep in mind that their are indeed slight differences.

[rxdc]

DON'T FORGET TO CLEAN OUT YOUR OILTANK BEFORE RUNNING BIKE AGAIN. In fact it is probably as well to strip and clean the whole engine or at least remove the top end. Remove sump pan and clean gause filter. clean the oil feed to the top end thru the capped nut at 110'clock to the points cover
Gary

[ericstew]

K0 camshaft is the hottest.The engine delivers 67 hp and the K1 65hp only due to a camshaft change(same carbs settings).Later models use different carbs setting to reduce pollution but same camshaft(not the F2).The worst is the Automatic one:only 60 Hp(using a F2 cylinder head!).

[the twig]

steelo
once you have done what all other readers advise, get a 1mm drill and very carefully drill out the oil rectrictor. dont go any bigger otherwise you will loose oil pressure to the top end. once i did this to my motor i had no more problems, but be sure once you have done this to change oil & filter every 5k to keep motor clean. happy riding

[Steelo]

steelo
once you have done what all other readers advise, get a 1mm drill and very carefully drill out the oil rectrictor. dont go any bigger otherwise you will loose oil pressure to the top end. once i did this to my motor i had no more problems, but be sure once you have done this to change oil & filter every 5k to keep motor clean. happy riding

This is intrigueing but a bit scary! Have any others heard of doing this? I guess if the hole was too big you could block it a little with "Vegemite" (The stolen Aussie Edible Gasket Goo!)

[MRieck]

worst is the Automatic one:only 60 Hp(using a F2 cylinder head!).

Actually the late K/Auto head doesn't have the larger valves of the F2. They do have the larger ID intake ports/mounting spigots/intake boots and keeper/retainer set up of the F2. There are 8 oil return oils as opposed to 4 for the F2 too. I'd say the late K/Auto head is the best head made for the CB except for the intake boots which have to sharp a turn in them because of their short length.