Pitch Control Prop with Sabb engine woes

[smonard]

Pitch Control Prop with Sabb engine woes

Finally took the boat out for the first time a couple of days ago. Its a 1969 Halcyon 27 with its original engine. The 8 or 10hp Sabb G series engine ran like a champ and didn't miss a beat. It has the Sabb variable pitch propellor with the pitch controlled from a lever in the cockpit. But... when we put in into reverse the boat moved very very slowly, when in forward it also moved slowly, barely able to reach 2kts. The pitch control lever was hard to shift when the engine was running. There was plenty of water churning about beneath the boat so don't think its the clutch slipping. Luckily we had sails so did eventually get back to the marina. Anyone know anything about these, seems like either the prop has something wrapped around it (unlikely) or probably the pitch is insufficient. I suspect something is worn in the stern gear preventing the proper pitch being set, any ideas? What is the likely culprit? Really don't want to take it out the water.

 

[KenMcCulloch]

Re: Pitch Control Prop with Sabb engine woes

Hi Portogeezer, Your berth is almost opposite me! Why don't you book yourself onto the drying berth for a tide, at least you can have a look at what's happening. I know nothing about Sabb variable pitch propellors but would be happy to give a hand. Incidentally if you have been stationary on that berth for some weeks it would be no surprise if you had weed or flotsam tangled around.

 

[smonard]

Re: Pitch Control Prop with Sabb engine woes

Cheers Ken, I should do that, I'm sure the bottom is coved with stuff and the log paddle wheel doesn't turn, it has been stationary for a while. I've noticed your very handsome FB across the way. I'm a bit nervous about the boat falling over when drying out.

 

[Bilgediver]

Re: Pitch Control Prop with Sabb engine woes

Seems you must be opposite me....I have a periscope for looking at propellers...We could look at it with the engine stopped and see what is happening...Should be around over the weekend.

 

[smonard]

Re: Pitch Control Prop with Sabb engine woes

Thanks bilgediver that would be awesome. I'm in C64, the boat has a pale blue deck, no dodgers and wooden combings. I'll be hanging about on Saturday.

 

[KenMcCulloch]

Re: Pitch Control Prop with Sabb engine woes

[ QUOTE ]
I'm a bit nervous about the boat falling over when drying out.

[/ QUOTE ]
No need, so long as you put a substantial line around the mast and ashore you won't fall over. However with Bilgediver on the case you should be OK, he knows about engines and propellors I think.

 

[oldvarnish]

Re: Pitch Control Prop with Sabb engine woes

I once had a Rustler 31 with the Sabb variable pitch. I found only two settings - slow and very slow. Once, I was hurtling into an Amsterdam marina with a fresh following wind and the foredeck crew shouted 'put her in astern.' I replied, 'She is! And has been for the last two minutes.'
Best thing to be said about a Sabb engine is that it is easily serviced with a hammer.

 

[smonard]

Re: Pitch Control Prop with Sabb engine woes

I'll prove you wrong old varish once I get to the stern of this. Its a lovely engine, huge and strong, like an old tractor engine.

 

[tillergirl]

Re: Pitch Control Prop with Sabb engine woes

This may not help but here goes. I use to have a variable pitch prop on an Albin and I guess the mechanics are pretty similar. First point is that if its two blade on a Rustler, the astern thing is not going to be that great. Mine never really performed astern. Second, on mine you 'went through' astern to feather the prop. It was very easy to go past the point of max stern thrust into the beginning of feathering for sailing. That used to generate enormous threshing of water and absolutely no effect on going or stopping! Once I had dried her out and marked the control lever with the max point of astern, we had a happier life! Third, when the prop is set up, an incorrect set up can really b**ger the performance.

On the Albin, the propeller shaft was a normal shaft that went from engine flywheel to boss of propeller plus a close fitting outer tube that moved forwards and backwards courtesy of the control lever mechanism. Inside the propellor was a rack connected to the tube which obviously moved backwards and forwards as the lever was moved. As the rack moved, it spun the propellor blades. There were two points to set up: one the attitude of the blades in relation to the rack. As I recall it to permit feathering, the set up for neutral (blades at right angles to waterline) was towards one end of the rack. Get this wrong and you could have two much pitch in ahead and not be able to feather. If the Sabb system is the other way around you might not be getting enough stern pitch on the blades. At the engine end where the this outer tube met the very clever thing that engaged the control lever - a device that impressed me enormously with its cleverness - there was another set up. As I recall the end of the tube had to be in line with a mark on the shaft. If this was out, again the pitch at the prop would be wrong. I also recall on the Albin system there was an 'o' ring that needed renewing each time the shaft and tube were uncoupled from the engine lest for fear of flooding.

The other time was that the Albin prop benefitted enourmously from grease - most of which oozed out from sundry places. You used to remove a blanking stud, screw in a grease nipple and squeeze away.

Hope this helps. Once I got it sorted I thought it was wonderful. Initially I didn't have a proper control lever and you could not keep the prop in neutral. You could never work out whether it would work its way into ahead or astern and SWMBO and I became very practiced at leaping ashore and lassoing cleats as the torque turned the prop into full ahead or full astern. People used to shake their heads at these two nutters who got off their boat leaving it full astern or full ahead. But there was nothing we could do until I saved up enough for a nice Morse system after which calm and tranquility descended upon the East Coast.

 

[bluedragon]

Re: Pitch Control Prop with Sabb engine woes

We have the Sabb H with VP prop. Very happy with it. Great little engines that will run on forever, and the VP mechanism allows very fine control at fixed engine rpm. Great for marina handling. Normally you should get plenty of thrust in both forward and reverse (5-6 knots in flat water). Might be something on the prop, but do you know for certain the clutch is not slipping? If it's not been properly adjusted and/or the lever not pushed right home, it can/will slip. Stiffness of the lever is normal unless you drop the engine rpm right down before trying to change pitch. There is a pitch control bolt at the back of the engine that sets max pitch, but only for ahead...so if this was set wrongly, it should still have plenty of power in reverse. The other things I can think of means stripping the prop down (worn internal parts...quite possibly the thrust rings). When you've eliminated all the other reasons, PM me and I'll dig out some info on how to do this. It's not difficult, but you do need a diagram and instructions. Let me know how you get on.

 

[ebbtide]

Re: Pitch Control Prop with Sabb engine woes

First boat was a Halcyon 27 and had no problems with engine, VP prop OR drying out, only electrolysis and de-zincification. Then they invented cathodic protection!
PM me for more.

 

[smonard]

Re: Pitch Control Prop with Sabb engine woes

Thanks for all your suggestions, I didn't think of the prop feathering for sailing, or that it could be over pitched in forward. We did notice when sailing that the lever moved all the way back by itself and was very reluctant to move forward until the engine was stopped. I need to see the prop see to what it does with different lever positions, I'll also check the clutch lever is fully engaged and pump a bunch of grease in everywhere. I'll see on Saturday whats going on. I have a manual for the engine and sterngear, the fine folks at Sabb have there manuals online.

 

[bluedragon]

Re: Pitch Control Prop with Sabb engine woes

Not sure I follow you here "We did notice when sailing that the lever moved all the way back by itself and was very reluctant to move forward until the engine was stopped".

When you say all the way back, what do you mean...from feathered? Because then you're in reverse. From the halfway point (feathered) there should be no problem moving it in either direction. If there is, then something is wrong. The need to reduce engine rpm is when going from full ahead to reverse, or vice versa on ours. One other point, over pitching the prop slows the boat down. The engine can't rev high enough because of the load the extra pitch creates.

The Sabb manuals don't give all the detailed info you need to strip the prop down as I recall. There were extensive notes from the previous UK distributor that explained much better how to do this, and set the clutch. You may or may not have these from the previous owner.

 

[smonard]

Re: Pitch Control Prop with Sabb engine woes

Thanks Blue Dragon. In my system when the lever is in the central position the prop is not feathered just the opposite, the blades are perpendicular to the direction of travel giving maximum drag. I don't think it is possible to feather this prop, you would have to go past maximum pitch and then some. I think I have sorted the problem, the linkage was connected wrong which didn't give enough movement of the lever on the pitch control/clutch housing, the cable went to the middle hole of that lever. I changed it to the inner hole nearest the pivot and I now can get maximum pitch. I pumped in a bunch of grease in and lubed up all the linkage and its now smooth as butter. I have yet to take it out but am optimistic.