Catalina 28 engine vibration issue resolved

[jansan]

For those out there with a Catalina 28 Mk1 with an engine vibration issue at low revs.

Had a great result with mounting the exhaust box on silicone " feet " in such a way that the box is no longer now in physical contact with the hull on the boat.This together with a new silicone " Hump Hose " from Trident has dramatically reduced the previously horrible vibrations throughout the boat whenever the engine was reduced below 1000rpm.

One comment when on a recent cruise from " old crew " is that somehow the boat now even seems more reponsive when under engine power -------- which may just be imagination --------- but then again there might be something else at work ?

There is still a very slight vibration when under power but one would expect that with the " solid " connection that the propshaft has with the cutless bearing.

Massive stride forward with motoring now a pleasure.

 

[Stu Jackson]

The hump hose has been around for many years, glad you found it. It also extends the life of your muffler, since the vibration was directed right at the inlet ports of the muffler.

What engine do you have? That'd help for us to know.

Did you buy the hump hose from Catalina Direct?

 

[jansan]

The hump hose has been around for many years, glad you found it. It also extends the life of your muffler, since the vibration was directed right at the inlet ports of the muffler.

What engine do you have? That'd help for us to know.

Did you buy the hump hose from Catalina Direct?

Got the Hump Hose direct from Trident via the internet and paid for via the UK agent for Trident. Great and quick service considering the potential for problems. Actually had the parts to hand before I got the bill from the UK agent !!

The Hump Hose was fitted last season and although it helped reduce some vibration the big improvement has come about from isolating the exhaust box from the hull. If you think about it -----every car exhaust " hangs " from the car chassis on rubber doughnuts so " isolating " the engine from the car chassis. I thought about " hanging " the exhaust box via stringers of some sort but the space availble around the box made this arkward.Hence the silicone feet as the fall-back option.

Engine is a Universal M20 ------ I believe fitted as standard to this boat .

Gear box is by Newage Engineering as I have had failures with several Hurth gearboxes. The Hurth box as fitted ( the smallest one ) did not seem up to the job.