Topic: CB550 k1 oil restrictor jets removal

[davidcumbria]

Stripping down my engine. Rockers looking like suffering from oil starvation. Have got the barrels off and want to remove the oil restrictor jets in the crankcase that feed the top end and act as dowels for the barrels. I can twist them but won’t pull out. So far, annoyingly,  have just scored the outside of the restrictor  trying to twist and pull with pliers. Don’t want to leave them in place when the case is blasted and also very interested to see how clear they are. How have others got them out ? I don’t suppose they are accessible from underneath when cases are split are they ? Can find nothing about this on here or in service manuals. Soaking overnight in penetrating oil and next  step is breaking out the heat gun but not hopeful. 
Thanks
David

[bryanj]

Done more of these engines than i care to think about and never had ones that didnt fall out if engine inverted so cant help there, lots of penetrating oil, heat and brute force but be carefull these are only available used now

[davidcumbria]

Done more of these engines than i care to think about and never had ones that didnt fall out if engine inverted so cant help there, lots of penetrating oil, heat and brute force but be carefull these are only available used now

Many thanks for the reply. Looking at those for sale on eBay most have rust where they interface with the crankcase. So I’m surprised you haven’t had this problem - just my luck. I might try freezing the jet with one of those sprays. Be interested to hear if anyone else has had my problem and will keep this thread updated.

[robvangulik]

I seem to recall Pewe pushed them out with pressurized grease from underneath.

[davidcumbria]

After a soaking overnight in AcF50 both jets could be turned reasonably easily. But turning and pulling up wards with pliers was getting me nowhere after half an hour of trying,  heating, freezer spray and more acf. In the end what worked was using a mole wrench and using the crankcase face as a fulcrum. The contact anulus is actually quite narrow so once they move a smidge they start to tilt and come out easily.  Both restrictors  were badly scored by the pliers / mole grips on their less critical outer surface. The effort ( approaching 2 hours I reckon ) was worth it because having removed them it was obvious both jets were partially blocked. There was a small piece of gasket bond in the cavity underneath one of  them. After cleaning them  out  light could be seen right through the jet and the pressure to blow through was much reduced. Hooray Ive found a smoking gun for my poor camgear lubrication. As for the scored jets they are now confined to my horrors shelf and a very decent used pair are on the way for a very reasonable £15.

[Don R]

 I take my head to the machine shop where the oil jets always seem to fall out. The problem is when they lose one.

[bryanj]

As you are in uk have you joined the uk forum? Bet those jets were from stratford on fkeabay

[Nurse Julie]

As you are in uk have you joined the uk forum? Bet those jets were from stratford on fkeabay

I'm sure we have a big stash of jets here Bryan, we seem to have a big stash of most obscure CB SOHC/4 bits 🤣🤣🤣🤣
Yes David , join us on www.sohc.co.uk

[BenelliSEI]

After a soaking overnight in AcF50 both jets could be turned reasonably easily. But turning and pulling up wards with pliers was getting me nowhere after half an hour of trying,  heating, freezer spray and more acf. In the end what worked was using a mole wrench and using the crankcase face as a fulcrum. The contact anulus is actually quite narrow so once they move a smidge they start to tilt and come out easily.  Both restrictors  were badly scored by the pliers / mole grips on their less critical outer surface. The effort ( approaching 2 hours I reckon ) was worth it because having removed them it was obvious both jets were partially blocked. There was a small piece of gasket bond in the cavity underneath one of  them. After cleaning them  out  light could be seen right through the jet and the pressure to blow through was much reduced. Hooray Ive found a smoking gun for my poor camgear lubrication. As for the scored jets they are now confined to my horrors shelf and a very decent used pair are on the way for a very reasonable £15.

I find these restrictors scary. The ones in my early Sandcast head are even smaller. They are just an alloy plug driven in the hole and then cross drilled to the stud hole. So easily plugged......

[davidcumbria]

As you are in uk have you joined the uk forum? Bet those jets were from stratford on fkeabay

I'm sure we have a big stash of jets here Bryan, we seem to have a big stash of most obscure CB SOHC/4 bits 🤣🤣🤣🤣
Yes David , join us on www.sohc.co.uk

Thanks Will do my intro on uk forum asap

[rollypoli]

Is this a common thing to do? I am rebuilding my k1 also and I am trying to do everything I should.

[dave500]

ive never seen them stuck in,ive had heaps of these 500/550s and never stuck or close to it.