2015 Tandem Island Mast jumping inside the base every tack,

The base is secure where it meets the hull bottom, and Turnbuckles are snug. The lock engages when the mast is set. Nothing is in the bottom of the well, or jammed in the pin hole, and nothing looks cracked, broke or missing around the collar area.

Pictures are forthcoming, in the meantime, whatever could this be?

Double check that the socket screw at the bottom of the V-base that pulls the whole mast assembly down onto the hull is tight, likewise for the locknut.
Also check the aka bar socket bolts are all tight.

The only thing that is loose or has any slop is the retainer clip whose screw where it pivots could be snugged up about a turn. Could this be the cause of the problem? Has anyone had this as an issue?

Also look closely at the mast drum to check it hasn’t slipped on the mast. The epoxy can fail.

Check the crossbar clamps. The crossbar may be moving side to side.

_________________
Matt Miller
Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA

Crossbar is solid. On a tack you can see the mast “jump” up and cock itself in the base with the accompanying clunk.

Notice the screw holding the release lever looks a little loose and angled itself. How much up-and-down play is acceptable for this part?



Don’t think there’s anything to see here. The nut at the bottom was loose but after tightening it up, the problem was no less diminished.



Or here-

What does your dealer say?

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Tony Stott
2012 Tandem Island "SIC EM" with Hobie spinnaker

Tightened the release lever screw. There's about 3/16" gap between the ledge on the mast, and corresponding notch on the release lever. With wind pressure, it's causing the mast to "jump" up 1/4" or more, and the clunking is the mast falling back on the pin when the sail luffs.

Is this within tolerances? I've had 2 older AIs and never had this issue.

I have a 2012 Tandem and have the same problem. With every upwind tack the mast would walk itself up a tiny bit so after a while the mast spool has creeped up 3/16" from where it should normally sit. If I roll in the sail I can re-step the mast and am good for a short time. Downwind and broad reach never seem to be a problem. I have 2 other AIs but only have this problem on the tandem.

I have played with the mast retainer clip, tightened, oiled, added tension to the spring and checked V-brace and bottom mast receiver bolt. Nothing seems to fix it & everything is tight. What did seem to help was adding a small shim under the mast retainer clip to add more stiffness. What appears to be happening is play in the retainer clip where the screw goes thu the slotted part into the mast cup. A bit of flexing on that retainer and the mast keeps wanting to crawl upward in tiny increments.

Anyway, now that the mast receiver has broken the replacement will give me all new retainer clip, spring ect. While I think the mast receiver & retainer clip are easy to use I would have preferred Hobie had used something a bit more substantial than the small plastic clip and tiny screw to hold it all down.

BTW I'm not sailing in anything extreme and yet I have to watch the mast spool location to the base like a hawk or risk catastrophic mast failure.