Has anyone had the same problem I am experiencing? It sounds as though the clutch is slipping - Is this possible as I am clueless when it comes to this type of gearbox? Up to about 2500 RPM, No issues at all. Then push her to the stops and the engine sounds as though she's racing without any load, back it of a little and she takes up the strain again???
Don't have a Hurth so can't say I have had your problem. But I do have a manual for the HBW Short Profile Sailing Gear. I took a look at it. There is a mechanically operate mutiliple-disc clutch in there.
The manufacturer does emphasise the importance of having the proper throw on the cable. The lever should move 35mm (1.37") in the top hole of the lever. Their exact wording goes; "if lever travel is shorter, proper gear engagement might be impeded which, in turn, might mean premature wear, excessive heat generation resulting in damage".
There does not appear to be any other adjustment on this gear which to me means if it is fully engaged and still slipping, it might be time for new clutch plates.
Take a look at your cable. Good luck with this.
Pete W.
Thanks Pete,
The latest update:-it's a bit of a story but recently I had the V drive overhauled. The previous owner had applied glass to the original mounts which enabled me to put the box back in exactly the same location. Which was great, when checking the prop shaft flange to g/box it aligned beautifully. At the same time I changed my engine mounts which had the effect of raising the engine about 1/8 - 3/16" this made little to no efect on the alignment to the top of the V box due to the length of the output shaft with fresh oil in the V drive I'm happy she is doing fine, however I now have noises like a girl screaming at a constant pitch coming from the depths ! ! Is it the Tranny? The engine doesnt rattle so much now that its not hitting its mounts so Is it a noise I've always had that I never heard before? The slipping clutch hasn't gone away but at 2500 revs she pushed us through wind over tide for six hours last week at speeds of 2.2 to 4.5 knots ( a jouney that took less than four under the same conditions a year ago). It took just less than four hours under main and drifter running at 7-7.5 knots.
Well I've just bitten the bullet and purchased a 4 year old tranny from eBay so we'll see how that turns out. If not good then I'll have one to strip and play with. I love my boat she teaches me so much Grrrr. Well its better than chasing a white ball into a ridiculously small hole for less than half the money eh !