Oil, oil pumps and primary chains

[Graeme77]

Thought i'd put this is a new topic.

Continuing my 'rattle' issue, i dropped the sump pan and investigated a little.

First off though, the oil sitution seems a little odd to me. Im new to all this though.

I drained the oil cold (i know, but the petrol tank was off and i was impatient).

Oil tank dipstick read about 1" above minimum.

I drained about 2 liters of oil from the engine (didnt drain the tank).

How much oil should be in the case? Manual says 3.5 liters of oil for oil change, seems about right for my total, but shouldnt it be mainly in the tank, reading higher on the dipstick? Engine was last run last night for about 10 mins. Been run for about 10 mins most nights over the last week.

Next thing is the oil seems very thin to me. Clean though. Sort of single cream consistancy. Seems thin for either 10/40 or 20/40.
I dont know what oil is in it though. Smells a little too, not 100% sure if it smells a bit like petrol, but its a bit fumey. Possible for petrol to get into the case?
Was a little bit of crap in the pan, but nothing major. Looks like little bits of scraped off gasket, probably from previous rebuild. Nothing that concerns me too much.

I was going to pull the oil pump anyway, check it over. Make sure the check valve is ok etc. Any reason why i shouldnt?

Now, the primary chain. Took a measurement to the chain adjuster. 69.4mm. Got to love digital callipers
JUST within spec. Ok to leave it for now? Its alot of wrk to change isnt it. Ok to leave it untill winter, maybe 1000 miles tops, or need doing now? Tensioner doesnt seem to have an awful lot of resistance/presure, pretty easy to pull back down. Ive no idea how much tension there should be though.

All looks nice up inside there though.


Thats more writing than i expected, so to sumerise...

1, distribution of oil between tank/sump ok, or odd?
2, possible for petrol to leak down?
3, primary chain, be ok for a bit, or do now!
4, oil pump, strip and check, or leave? Sort of depends on the answer to 1 really, is it scavenging properly.

Thanks
Wish i hadnt spent the last 17 years purely messing with cars now, might know a bit more about bike engines

[K2-K6]

Primary chain tensioner is not that strong it just keeps the slack at bay and slows down a bit of backlash nothing more. Sounds reasonably ok from your inspection.

The primary seems easily strong enough to take the strain from a standard motor and shouldn't give many problems. I believe it has a harder time if you were to thump it down through the gears as when the torque is driving the crank from the clutch then the tensioner is pushed out of the way so the chain can flap around (I guess if it was really too worn it runs the risk of trying to wrap round the crank in the above scenario) it's very rare to hear of a road bike have a problem with this though.

Petrol will get into the oil if you keep running it on choke, in my opinion it will also kill the engine (loss of protection for plain bearings and cam) if left like that so worth changing it asap.

I've always run 20/50 oil in these with no detergent addatives.

Oil system is a two stage dry sump. Scavenge lifts oil from sump to tank and there will always be oil in the sump pan or the pump would suck air. second stage of pump is fed a stable supply from tank and feeds direct to bearing system so should be maintained above minimum to avoid air intake there as well. levels sound about right I usually check this with the bike level and engine running.

[kaceyk2]

Hya Bro, when you say you got two litres out of the sump, is that just from undoing the sump plug?
Or did you take the oil filter and container off from the front of the motor and count the oil that came out of that too?
The whole system has a three litre capacity, and if you found two litres in your sump, then I would cetainly check out the check valve and pump.
These old girls have a dry sump system, Furthermore 10/40 oil is recomended. (those restrictors are pretty small for oil that is too thick on a winters day!)
Drain the oil tank, and give it a clean out whilst you are at it, this never hurts, especially if you suspect the oil of being dodgy or smelling funny.

Check the oil pump/ and or check valve out in a meticulously clean enviroment, do it methodically, and keep everything scrupously clean... Imagine your work area is going to be for a surgeon to operate on you, and you wont go far wrong!

Any probs, report back.. have you got a manual?

[steff750]

  in reguards to the amount of oil in the sump , i would say its just WET-SUMPING, as oil does get pass the oil stopper valve over a long period of time,if the bikes left standing, this is disasterous on old brittish bikes as it cant suck up the oil and blows the seals,but not a problem HONDA CB750,S they just suck the surplus back into the oil tank,i bet if you had warmed the bike up first you would not have had 2 litres of oil in the sump 

[Graeme77]

Ok, thanks folks.

I have the chelmer? book and a copy of the factory manual.

Ill take the oil pump out while im in there and check it for good measure.

Ill leave the chain untill winter. Good news that, cant really afford to do it yet.

On a seperate note, i found a place selling primary chain and tensioner kits.
They described it as an 'simple to fit kit'.

I wouldnt call what is esentialy a complete engine strip simple LOL.

Ill strip and go through the engine in the winter when its off the road. Plan of powder coating the frame then too.
Fumjey oil from running on choke sounds about right, has only realy run on choke recently.

For future reference, if the engine has just been run the oil should read near the max on the dip stick right? With a properly working pump/check valve, how long would it normaly take to run down into the sump?

Ill clean the pump up, fit a new filter, clean tank and refill.

Thanks for the advice.

I havent took the filter off yet either. The 2 liters is a guess, but thats just from the sump. Sump plug was stuck solid (still is) so i just dropped the pan.

[Graeme77]

Oil pump is out, check valve was stuck fully open.

I think the pressure valve was stuck too.
Not going to open it up, ive free'd up the stuck items so ill re-fit it as it is.

Need new O rings as the old ones are a bit flat.

Oil filter looked mank, but have 2 new spares. I even took the roll pin out of the oil filter bolt to make sure the little plunger was free. Dont know what it dos, but if it is supposed to move ive made sure it does

The 1 liter or so of oil left in the oil tank had drained out over the last 24 hours, luckily the catch can was still under the engine!

Tried to get the neutral switch out to check too, sometimes you put it in neutral but the light doesnt come on for a while. Figured the switch might be sticking.
Unfortunately the terminal screw is solid and rounded out and the 10mm bolt is stuck fast. Its soaking now, hopefuly ill have more luck tomorrow. Annoying that the frame is in the way, stops me getting any decent tool on it.

Speaking of O rings, anyone changed the one behind the counter shaft bearing holder, behind the gear change mech? Read on the other site that it helped the guy's problem of getting it into neutral when stationary.
The screws rounded out on him though, anyone else experienced this?
While im at it i might as well do all the crappy little jobs.

[Graeme77]

I see most people like mineral oil rather than semi synthetic.
Are you finding mineral mitorbike oil, or just using normal car oil?

[kaceyk2]

Thought you would find something amiss with the check valve,  I am glad you found the problem quick and sorted it out. Two litres was much to much to find in the sump!!

you say you have the clymer manual, watch out, for the Torque on the oil filter housing bolt, If I am remembering correct the clymer gives it as something reall y really WRONG, like ridiculously high...
You do not want to strip that bolt..
Be carefull with it, the correct torque is 20 - 24 ftlbs.
hope this helps.

[Bryanj]

Tesco 10 w 40 mineral Diesel oil at

[SteveD CB500K0]

Don't use car oil. Just Google it if you want chapter and verse!

[Spitfire]

Still use Duckhams 20/50, change the oil and filter every 1000 miles. Although that Tesco oil that Bryan mentioned sounds interesting.

Cheers

Den

[UK Pete]

Tesco 10 w 40 mineral Diesel oil at

[totty]

I'll stay out of the car oil debate, had a few arguments on other forums about it..... but do you have a link to the place selling primary chain and tensioner kits? They may be of interest to owners of the bikes that don't have one like the 550.

[Graeme77]

Ill try and find the link again, but the 'kit' was just the chains and tensioner together, for the cb750.

Tesco diesel oil?

That'll be for cars then

I did google about car oil but didnt find much, ill look again.

[Graeme77]

Thought you would find something amiss with the check valve,  I am glad you found the problem quick and sorted it out. Two litres was much to much to find in the sump!!

you say you have the clymer manual, watch out, for the Torque on the oil filter housing bolt, If I am remembering correct the clymer gives it as something reall y really WRONG, like ridiculously high...
You do not want to strip that bolt..
Be carefull with it, the correct torque is 20 - 24 ftlbs.
hope this helps.

Thanks, i tend to use the factory manual anyway.

My oil filter bolt has a 21m nut welded on it! Was pretty tight LOL.

Im not a big fan of torque settings anyway. The only things i torque are heads, flywheels, con rods, rockers, things like that. Anything else gets done how i want it done. I'd rather trust my experience, gut instinct and the feel of it on everything else.
I dont even torque clutch bolts
I guess alot of folk will laugh at that, but ive never had any problems in 17 years of re-building and modifying old engines, even on ones converted to turbo and running high PSI figures.