I fitted the cycle computer today and it worked like a charm (assuming its telling the truth!).  Seems that I am low idling around 275-300rpm, cruising between 375 to 500+.

Also, I have corrected my description from Crunch to Clunk as crunch was a bit misleading. I have found that PRMs do have a reputation for being ‘clunky’ in certain circumstances and I am currently looking into installing a soft-shift valve which purportedly often cures the problem. Expensive though at £4-500.  Beta Marine also offer an accumulator that does the same job - I am currently waiting on a response from them.

Thanks Steve.

That cycle speedo idea is brilliant.  I will certainly give it a try.  I do have the specs for the PRM and I recently had work done on it so I am confident it is ok.  Trying to match the RPM as a first solution seems to be the best bet. I will order a computer soonest and let you know.

Hi,

I am running a jP3 in a narrowboat and am currently on the River Stort.  It has been shallow/weedy and places (deep draught)  so the engine has been loaded up more than normal.  This has been exacerbated by weed regularly wrapping around the prop causing even more drag (and load). The result is more smoke than usual (expected?) but also a lot of oil has been spraying out the vertical exhaust. There was actually pools of oil around the base of the exhaust (on the roof). Is this what you would expect when under heavy load?

I was advised, at purchase, to oil the rockers/valves etc and fill the cylinder head recess prior to each start, which I do. The manual only says to do this after a service/starting first time etc. Is it necessary to do this every time given that each running day is, at most, 4-5 hours and never at full revs?  I sometimes wonder whether I am giving her too much oil although I do keep an eye on the dipstick level.

Any advice/experience welcome.

Cheers

Steve