Forum

[Dezzy]

Hi. My Connie quickly dumps most of its engine oil into the sump and primary chaincase after several minutes running. A new top end (barrels and pistons) have not cured the problem which I thought maybe caused by increased crankcase pressure from a badly worn top end.

I then turned to the pump. On the larger return side, the spigot that drives the disc plunger very slightly fouls the cover evidenced by a light circular scoring. Easily cured with a thicker gasket or removing a few thou from the length of the spigot. End float????

On the feed side, there is slight damage to the disc, but it is where the spring recess has been machined,it leaves a thin wall of material adjacent to the plunger rod. This has broken away so the recess is not continuous leaving a gap at the edge of the flat milled area if that makes sense.

Anyhow, IMHO,K cannot see these defects ruining my scavenging. Or will they? I appeal to the vast knowledge base out there for guidance. Many thanks. Can send photos if anyone sufficiently interested.

[Cleggy]

You may have incorrect pump parts fitted. I would replace the pump discs & spindle. They sound like they are damaged/wrong type. Then conduct a thorough test of the oilways (Scavenge side anyway) to ensure they are clear. After that I'd be testing the return pump action. Primary side crank seal may be knackered, or just overwhelmed. You will need to become an expert at knowing exactly which return pump hole goes where both before & after the pump. Sounds like the return pump is not functioning; & the feed pump disc damaged but evidently working. They could be pump parts from an Interceptor or other model which might misalign the pump oilways. You can test the pumps with the timing cover off & turning the spindle by hand (if you know which hole does what).

[Mark M]

Sound advice from Cleggy there. Could you tell us something about the history of the bike? Has it been in your possession long, and either way, what work recently done? running well before? And anything else relevant, diagnosis in a vacuum is hard work!

REgards, Mark

[Dezzy]

Thanks for the suggestions. I have researched a little more and all 700 twins and Mk1 interceptor seem to have the same part number for the spindle and discs so the problem lies elsewhere. I used compressed air to blow through the return holes in the crankcase and got sprayed with oil from the oil tank return pipe so that is good. Similarly the feed holes are clear,so will just replace the discs and plungers and take it from there.

Just as a matter of interest I have noticed that even when the TC gasket is lined up with the fixing holes, there is still the potential to partially cover the small supply and return feed holes in the crankcase.

Finally, while I have the timing cover off, might it be a good idea to fit a breather in the mag area of the rear timing case and tee it into the breather at the bottom of the nearside cylinder directly into the top of the oil tank?

Thanks all. Your advice is most welcome. Dez

[Marko]

Hi Derek yes you could do a breather from the mag area if you wanted to (I wouldn't, i'd do it the way mentioned in the Gun " breathing article" even though that does mean parting the c/cases). Anyway, back to your idea: yes you can if you want to but I wouldn't T it to the breather you mentioned - i'd route it out to atmosphere via a one way breather (flap valve, reed valve, duckbill breather etc), anyway, good luck hope you get it sorted (theyre bloody good bikes when theyre sorted!), all the best, Mark