Aloha everyone,
Ok, long story but bear with with me... question comes at the end...
After for some time having had a bit of a too weak return flow to the oiltank at took the pump apart. It turned out so be quite warped in the surfaces between the body and the "lid" on the feed-side, there was also a large amount of play in the gears up and down in relation to the body/lid. It was obvious the pump was a bit worn, and the oil flow therefore to weak!
After some work making the surfaces flat I had to grind the gears in with paste in order for them to turn freely. Refit the pump and voila! ...the same weak dripping from the return pipe. And after a little while oil started pissing out of the crank vent hose, like really flowing. I quite clearly had fixed the pump one way but not the other. :wink:
Took the pump apart again and refurbished the bottom part of the pump, it had quite a bit of play and also the surfaces were rather warped. Fixed it and put everything back together and I now have the strongest return flow that I have ever seen och an engine with roller bearings, when revving the engine it was almost to the point where it flooded straight out from the pipe a la my Triumph Bonneville.
But still some oil coming out if the crank vent.
Before I take it apart once again:
Is there any other probable cause for this than the feed side of the pump being "too good" compared to the return side of the pump?
Best regards,
Simon
(Oh, and I have the automatic checkvalve on the feed side so no wetsumping while parked issue.)
What, not a single thought on this?
I assume you all fell asleep while reeding and never made it through to the question at the end... :innocent:
Best regards,
Simon
Did you drain the crankcase completely after you did the second repair?....It sounds as if you might not have....The strong return to the oiltank should only last as long as there is oil in the crankcase..When that has been cleared the only return you will get is a 'spit and bubble', as the larger capacity return gears will scavenge (empty) the crank case...
However, if there is too much oil in the crankcase from a previous weak return side on the pump it will be too much for the pump to immediately deal with and will be ejected from the breather until everything returns to the correct state...
If the bike is left standing and the engine 'wet sumps' as the oil drains into the engine you might get exactly the same result the next time you start it up unless you first drain the crankcase..
I don't like repeatedly taking out and replacing the drain plug as it can compromise the thread in the crank case..On all my engines I drill through the plug and tap it to 5mm to take a 5mm allen screw and fibre washer...That way you can just remove the screw to drain it and leave the plug in the cases.....Ian...
email (option): ian@wright52.plus.com
Yup,
Crankcase was drained, since I had the oil pump out that way in order to repair it. I always find it to be quite a nervous moment before the oil starts returning to the tank.
I have an aftermarket sump-plug of quite thick aluminum so no real worries about the threads.
Best regards,
Simon
Likely to be a bad flapper valve on the breather or even bad rings
I had a piston pin clip come loose and make a nice groove down the barrel
Up till 1/2 throttle ran like a gem
Over 1/2 throttle waterproofed everything behind and left a reaaly big pool of oil under the bike when parked .
Just trying to be helpful.
https://pesltd.uk/?product=15-0082
Mark
email (option): pes.sales@btconnect.com
Hm, interesting points gentlemen.
Thing is though, flap disc i just about new and the same goes for piston, rings and bore. I am kinda wondering if there is just plenty of oil in the "flap disc vicinity" from the first round of wetsumping...? I did rinse out the vent hose itself, perhaps I should take a look at the flap disc and what else. Maybe there isn't really a problem, just a case of airing it alla out...
However I did take the pump out (again) yesterday and found that the cogs on the return side measures a tiny bit smaller than some other cogs I had laying around. Going to put them in instead and adress the flap disc as well.
Keep ya posted!
/Simon
Hello again,
Today I finally found the problem:
The two holes in the pump body where the spindles/axels of the gears/cogs for the returnside sits hade become warn and loose to the point where they would let oil seep through. This then becomes an easier path for the oil to go rather than being pushed up all the way through the oiltank. The oil ended up going through to the feed side of the pump along with the new oil that is being fed from the tank. Voila wet sumping!
The problem only occurred when I fixed the feed side of the pump (se above) because before that the amount of oil going in was not enough for wet sumping.
Had a small bag of pump parts laying around and it seems I got it together ok. Did some driving round the block a few times and up and down the street and no dripping from the crank vent. Great success!
Best regards,
Simon
Glad to hear you found the answer Simon...It's always interesting to hear of an unusual problem...Ian
email (option): ian@wright52.plus.com
Best regards,
Simon