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Re: Severn Cruising
« Reply #141 on: Jun 30, 2019, 9:49 pm »
Took my neighbour out on the craft today - he's been out once before, so I thought it about time that he had a little instruction in the art of hovercraft piloting. No real trouble for him, despite the slightly gusty breeze and twisty river giving plently of opportunity for learning!



Ian
Ian Brooks
Gloucester, UK

Re: Severn Cruising
« Reply #140 on: May 20, 2019, 10:43 pm »
Last year at Loch Fyne I had a couple of occasions when the engine missed a beat, usually just for a second but not enough to deflate the skirt. After a while I noticed that it only happened one one tank (I have two tanks, both have integrated fuel pumps and gauges). On home turf I can get right out to the Severn Bridge and back on one tank, so the issue has remained dormant all year! I finally got around to looking at it tonight.

I had a spare fuel pump, so first I just changed that along with all wiring on the basis that must fix it! Then I took apart the old one to diagnose the problem.

The wiring appeared intact at first sight, but a gentle pull showed that it was just the heat shrink holding the wire to the terminal. The connection was properly strain relieved by the heat shrink and connector backshell, and there was no bvious corrosion, so I  suspect a dormant dry joint. It took 6 years to eventually turn into a crack. I'll have a look under the microscope tomorrow and see if that is the case.

« Last Edit: May 20, 2019, 10:57 pm by Ian Brooks »
Ian Brooks
Gloucester, UK

Re: Severn Cruising
« Reply #139 on: Apr 19, 2019, 1:41 pm »
If anyone is looking for an "emergency engine" I have 2006 Mariner 3.3 hp two stroke LONG shaft. It is in excellent condition and used for about 3 hours having been an emergency engine for my rib. (Which I sold)
 As a precaution last month I changed the waterpump impellor and the lower unit gear oil.
Anyone interested PM me.

Re: Severn Cruising
« Reply #138 on: Apr 19, 2019, 9:47 am »
A temperature gauge would give an early warning of something wrong!!

Re: Severn Cruising
« Reply #137 on: Apr 19, 2019, 8:37 am »
Im so used to air cooled thumpy things i would never have thought of that.  ::)
If this turns out to be the problem-----

Perhaps a low warning sensor in the coolant system?



Memories are BETTER than Dreams---"Capn" FLINT

Re: Severn Cruising
« Reply #136 on: Apr 19, 2019, 8:17 am »
Well done on Plan B Ian - I do like a Plan B...... and C and D if possible!! Hope the fix is an easy one 8)

Re: Severn Cruising
« Reply #135 on: Apr 18, 2019, 9:21 pm »
Any sign of water in the oil?

Re: Severn Cruising
« Reply #134 on: Apr 18, 2019, 8:27 pm »
It is possible to have water in the header/expansion tank and none (or little) in the engine/radiator - assuming it's a unpressurised expansion tank?  It takes a few hot/cold cycles to equalise the water volume in the system.  In theory, air (and coolant) is pushed from the radiator into the expansion vessel as the engine heats up - when it cools, the water is sucked back into the radiator through the cap (it has a one-way valve to allow this - as well as the "normal" pressure valve in the other direction.

Might be worth checking for a drip from the water pump leakage hole?
« Last Edit: Apr 18, 2019, 8:41 pm by John Robertson »

Re: Severn Cruising
« Reply #133 on: Apr 18, 2019, 8:00 pm »
Looked at it today -no water in it.  It was ok (at least there was water in the header tank) before I set off. Must be a leak somewhere though. The engine was pretty hot when it stopped, but seems ok now that theres water in it. It has a temperature sensor and is programmed to shut down at about 115C if I remember correctly.

I suspected a water leak yesterday when it happened, and thought it was probably a big one but no obvious sign of it today. More investigation needed, but at least the engine protected itself and survived the ordeal. Hurray for modern electrics!

Ian
Ian Brooks
Gloucester, UK

Re: Severn Cruising
« Reply #132 on: Apr 18, 2019, 9:15 am »
"Oooooh the SOUND of silence"
With Simon AND Garfunkel wailing away in the background, I'm sure we all commiserate, as flash backs (or is it "flashes back") crowd in on ones memory bank. Yuk (apart from the the well earned beer on the bank) swiftly followed by all the WHYs?
Not however "WHY am I doing this?"---- oooh no- just the cause (s) and prevention/mitigations necessary to avoid repeats.
I hope the severn banks (WHY so many??????! ;) ) ECHOED to that good old Yorkshire BELLOWED expression---------
---------------------------------------------"SOILED - ME - PANTS"------------------------------------------------
                                                                         :o
Memories are BETTER than Dreams---"Capn" FLINT

Re: Severn Cruising
« Reply #131 on: Apr 17, 2019, 9:42 pm »
Well it's been 4 years that I've been solo cruising from monster worth, it had to happen eventually. I took the craft out for a short cruise after work, started it going a few miles up river then came back. Passing my place I headed off down river bound for Garden Cliff or Hock Cliff. Didn't get too far before the engine went down to one cylinder then cut out. This was 6ish with the tide due at 7:50 so no time to faff really, engage Plan B without further ado!

Plan B consists of a tiny Chinese outboard, this was deployed to bring me to a suitable spot on the bank to tie up and to get out to the road. It really doesn't have the puff to oppose the current, but there's a world of difference between in the stream and on the bank (especially if it's the right side!). Once the craft was tied up I had about a 2 mile walk back to my place to collect the "tug", a 14ft Dory with an ancient 40 horse mariner on it.

The boat was soon in the river, and in fine 2 stroke style started first pull (really!) But I won't mention that it stopped after a few seconds then was a right bugger to restart :-\ but start it did so we were good.

Taking the craft into tow was no faff at all, although steering was "interesting" as we made a drunken return journey at a decent walking pace.  And then the beer. Still, the boat has now earned its space on the bank!




« Last Edit: Apr 17, 2019, 9:53 pm by Ian Brooks »
Ian Brooks
Gloucester, UK

Re: Severn Cruising
« Reply #130 on: Mar 23, 2019, 7:38 am »
Little trip out today - in deference to the huge tides this weekend, upstream rather than downstream. In truth upstream is a bit dull really once you've done it a few times but it suited me to go out and given that a huge bore was expected in the evening it gave me a chance of recovery should I have a breakdown. Breaking down in  the lower Severn on such a tide would mean the loss of the craft almost without doubt. Not to mention the chance of a little helicopter ride!

The bridges at Gloucester and Maisemore were a bit touch and go - I got under them (slowly!) but there was not much to spare with the amount of water coming down the river from Wales. Makes for a good bore though!
Ian Brooks
Gloucester, UK

Re: Severn Cruising
« Reply #129 on: Mar 09, 2019, 10:57 pm »
Finally fixed it.  I put a new solenoid in, only to find the symptoms unchanged. Doubting my original diagnosis, I methodically went through the whole system with my meter, on to arrive back at the same diagnosis - defective solenoid. Which is of course brand new. Removing it from the circuit confirmed an open circuit coil 😥 Still, found another solenoid and it's all good now.

Also cranking much more energetically - this issue has been developing for some while. Ordered a replacement for the spare (carried on the craft) which I will bench test when it arrives!

 
Ian Brooks
Gloucester, UK

Re: Severn Cruising
« Reply #128 on: Feb 16, 2019, 6:37 pm »
Those loud blue flashes are most unnerving, as you "feel" its YOU being electrocuted, and NOT the spark to earth---
Ive cut myself whilst withdrawing my hand VERY fast in the past!  :-[
Memories are BETTER than Dreams---"Capn" FLINT

Re: Severn Cruising
« Reply #127 on: Feb 16, 2019, 5:51 pm »
Three rules:

If something changes with your hovercraft, find out why
Don't turn off your engine if you're in an exposed position
Only stop somewhere you can walk out of

Two broken!

Turn key : nothing. Sh*te!

Should have investigated why it was turning over slowly when I started. With tide coming in, the only saving grace was that I chose to stop on the bank rather than an isolated sand bar and the light failing.

It was about a 30 minute walk to the road, but I wouldn't be able to leave the craft until high tide about 7:00 so that will be in the dark :( so thats plan B. At least I did have a plan B - If I'd been on the sandbar it would have been mayday, much bigger craft get rolled over by the flood tide on these sandbars.

Plan A is fix it. Break out the tools, soon found the dead solenoid. I carry a spare but given the gathering darkness a spanner, some big blue flashes and loud cursing had it running again.

Phew! New solenoid in the morning.

Ian

Ian Brooks
Gloucester, UK