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transmitterdan · 10-07-2015, 06:02

Your installers are not telling you correctly. If you have enough solar to power your boat then you don't need an 1800AH bank. Especially so if you have a generator to top up on cloudy days. Your bank is too large for solar/wind to charge it properly. You need a bank of about 800AH in my opinion. Then you have a chance of solar/wind keeping it topped up every day.

Lithium would be good for your situation too.

DeepFrz · 10-07-2015, 09:59

Quote:

Lithium would be good for your situation too.

Only if you know how to use and maintain them. Lithium can not be discharged to zero without serious risk. LiFePo4 batteries need to have LV and HV disconnect.

Here is what lifeline say about their AGM batteries. It may be a bit optimistic but its closer to the truth than what you have been told. Information on other manufacturer's batteries can be found on the web.

Quote:

Unmatched Life-Cycles-
When discharged to the BCI recommended 50%, Lifeline batteries provide nearly 1000 life cycles, which is significantly more than other technologies. Other flooded and gelled batteries fall between 300 to 450 life cycles at 50% discharges.

yttrill · 11-07-2015, 19:59

Update on engine issue: I now have a good idea what happened. When the last service was done, the decompression level was disconnected from its control cable and the cable applied to the throttle instead.

Unfortunately, the decompression lever rotates through 180 degrees. In the on position with the cable pulled, the screw ends passing through the control rod prevent the valves fully closing. In the 90 degree position the decompression stops are disengaged. The cable would normally be fully pushed in for this position. However without the cable the lever will continue to rotate to 180 degrees bringing the screw heads with their lock nuts in range of the rockers. This is certain to be what happened because the screw heads are chewed out.

Then the vibrating force on the screw heads caused the free end of the control lever to vibrate, eventually snapping the control lever at the midpoint where the central bearing with the friction fit blot is located. The broken off rod then bounced around inside the rocker housing, jamming the rockers and bending the push rods. There is some damage inside the housing indicating this is what happened. The two valve clearance adjusting screws associated with the bent push rods were also so badly chewed out I had to use a hacksaw to open up the slot for the adjusting screwdriver.

I think this is a design fault in the Kubota Z600. When assembling the system it would be hard to screw the stoppers into the decompression control rod if they could not face out of the cover, so they're allowed to sit in that position even though if they were in that position during operation it could cause the problem that i had. [To adjust them, they are 180 degrees from that position and there are special cover plates that can be removed to perform the adjustment.]

There should be a lock that can be put in place after assembly to prevent an unsecured decompression control rod turning into the dangerous position. Relying on the control cable seems a bad idea.

Since I only have a decompression control rod i will remove the stopper from it and put it back in place (to allow the seal to prevent oil leaking out). However I will have to secure it somehow to prevent it falling out. I could also just put a cover over the hole. Repairing the control rod looks tricky. A weld would add to the length and move the stopper out of position. The ends would have to be ground down to account for this. Not sure it's worth it. Decompression lever is a nice tool but I guess I can live without it.

yttrill · 11-07-2015, 20:21

Quote:

Originally Posted by DeepFrz

Only if you know how to use and maintain them. Lithium can not be discharged to zero without serious risk. LiFePo4 batteries need to have LV and HV disconnect.

There's little need, it would all be done by a computer. My personal design would use three Li batteries: one being charged, one being discharged, and a buffer to allow the switch over without spiking. I'd probably combine this with AGMs somehow I haven't really thought about because I'm broke

Quote:

Here is what lifeline say about their AGM batteries. It may be a bit optimistic but its closer to the truth than what you have been told.

I've done quite a bit of research. In your quote it says 50% discharge give 1000 cycles. That's precisely why I have a LOT of batteries and never discharge below 75-80%. That gives a lot more cycles. 1000 cycles would be utterly useless. That's only 3 years. Multiple electricians have told me that the number of cycles increases significantly by raising the minimum charge level. I have got 7 years out of mine so far, and these are therefore using 7 year old technology. That's over 2000 cycles. Anecdotal evidence I know.

hellosailor · 11-07-2015, 20:37

yttril-
It sounds like your former mechanic needs to spend 48 hours in a telephone booth with Mr. Rubber Truncheon. There won't be a mark on him, but he will be a great deal more careful in the future if he goes back to mechanic-ing.

Plugging the hole can be easy, just depends on how much force/pressure might be on the plug. You could take something like a 3/4" nut or flange nut, and simply epoxy it on the OUTSIDE of the housing. Then screw a short bolt into the nut, using some blue Loctite. Bolt in, hole secured. Bolt out? And a new rod can just be slipped in, without even knocking off the nut. Or just drop a 2-3" plate or pipe end cap over the hole, and only apply epoxy around the outside 1/2", so it can't get in the hole. Knock it off when you get the new rod for it.

I heard metal rods are most finely tempered when they are reforged and quenched in the blood of a living mechanic....

yttrill · 11-07-2015, 22:51

A bit straighter now.

yttrill · 12-07-2015, 18:46

It's RUNNING! No popping sound. Higher revs too. I haven't done the valve clearances because I don't know the right numbers (and don't have any feeler gauges yet). Just have to hope the push rods stay straight. (well they're not entirely straight but the best i could do)

Thanks to everyone that helped!