Waking up a Darmah

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Phil Ranucci
Cucciolo - the Lil Pup
Posts: 4
Joined: Wed May 28, 2014 8:38 pm

Waking up a Darmah

Post by Phil Ranucci » Mon Jul 07, 2014 7:44 pm

First post here. I'm going to try and get my '78 Darmah running this summer. It's been sitting for 15 years, and I need some advice on where to start. I'll be coating the tank and rebuilding the carbs. What to do about the engine? I won't try starting it or even kicking it over. Obviously, the engine could be rusted solid even though it's lived in a garage. Assuming it isn't, and realizing a rebuild is not in the budget, how should I proceed?
My idea is to spray Kroil into the barrels and let it sit for awhile. On the centerstand, try to turn the rear wheel and see if the engine frees up.
Am I delusional or might this work? Any ideas?
Thanks,
Phil

GeoffW
Mariana
Posts: 43
Joined: Sat May 19, 2012 2:01 am

Re: Waking up a Darmah

Post by GeoffW » Tue Jul 08, 2014 4:54 am

I'm no expert on reviving engines that sat for a long time but if it were mine and it sat for 15 years without being regularly turned over - I'd dump the old oil and put some fresh stuff in there, turn it over lots and lots to get the oil circulated thoroughly with the plugs out, then check for compression before firing it up. If there's corrosion in the bores or other problems they will show up after it's run for a bit. Did you check valve clearances?

GeoffW
Mariana
Posts: 43
Joined: Sat May 19, 2012 2:01 am

Re: Waking up a Darmah

Post by GeoffW » Tue Jul 08, 2014 3:26 pm

I dunno what Kroil is, but I'll assume it's like Penetrene, the idea being to free the pistons & rings in case they have stuck in a corroded bore, is that right? If yours is a 78 model then surely it has a kick starter which would be easy enough to turn the motor with. Still, if you suspect corroded bores maybe the cautious thing would be to pull the heads and have a real good look first, in case you can salvage the existing bores/rings with a gentle clean up by hand. If you've not had the heads and barrels off before, it's really quite straightforward if you need a little guidance through the process I can help. Of course it's possible I've just demonstrated my ignorance, but I'm playing it cautiously because you are on a limited budget....but I'm interested in what others might chime in with too for sure.

Phil Ranucci
Cucciolo - the Lil Pup
Posts: 4
Joined: Wed May 28, 2014 8:38 pm

Re: Waking up a Darmah

Post by Phil Ranucci » Sat Jul 12, 2014 9:53 pm

Thanks for the replies. Kroil is a "creeping" oil that is supposed to be able to free up light corrosion. The oil will be dumped before anything else is done. I think that pulling the heads might be beyond my abilities, but I'll check the shop manual. I'd be worried about getting the timing wrong afterwards. Yes, the bike has a kick start. I was planning to use that to turn it over once I'd sprayed the bores. It still needs a battery, anyway, so this will be a leisurely process. Have not checked valve clearances, it ran fine when parked. Stupid question, can they change from lack of use?
Thanks again!

GeoffW
Mariana
Posts: 43
Joined: Sat May 19, 2012 2:01 am

Re: Waking up a Darmah

Post by GeoffW » Sun Jul 13, 2014 2:28 pm

Pulling the heads is really not difficult at all. By all means consult the service manual and don't rely on me alone, I hope somebody with more experience chimes in with a second opinion. On the Darmah after removing plugs, carbs, manifolds and exhaust (from memory here, it's been a long time since I had one), you need to tip the engine forward in the frame, which necessitates removal of engine side covers (I'm pretty sure) to clear the front frame down tubes. This is not a bad thing because you can get a look at things with those covers off anyhow and clean out any muck. So you tip the engine forward, line up the timing marks on the bevel gears etc, then undo the head nuts (I do that sequentially diagonally a little at a time just like when tightening them) - once the head nuts are a few threads up you start lifting the head or gently tapping (not on the fins) with plastic mallet or similar if required and the heads come off pretty easily. Keep an eye out for o-rings, which will need replacing. Once the heads are off it's much easier to check condition of the bores and check valve clearances/valve seats & guides/seals etc. The other thing now is it's a very simple step to get the cylinders and pistons off so you can measure them, de-glaze the bores if required (without taking much metal off) or put rings in if required. Depending on mileage you also have access to the sludge trap plug in the crank bob-weight that can be unscrewed (I use an impact driver, not sure what other people use) and cleaned out before replacing with new plug and locking back in (locktite & centre punch edges), assuming there's no excess play in the big ends that necessitates a serious rebuild you can then pop it back together with new cylinder base gaskets new head o-rings and be confident it won't weep oil due to perished o-rings sitting there for years. As for valve clearances, you can check them more easily with the heads on the workbench, plenty of info out there on how to do this stuff.

Of course it's your bike so you might just wanna stick new oil in it after checking the pistons move freely and fire the old bastard up instead.

wdietz186
888
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Joined: Sun Sep 10, 2006 4:40 pm

Re: Waking up a Darmah

Post by wdietz186 » Sun Jul 13, 2014 3:28 pm

If it was stored in a relatively dry environment it should be pretty easy to get running. You've really got nothing to lose by pulling the plugs and trying to turn the engine over. If the bores are rusted, no amount of penetrating oil will fix anything beyond freeing it up. The cyl. walls will be pitted and the ring faces will have been eroded and that means rings and a rebore.
I found a 650 Yamaha that had been sitting for 20+ years in a garage here in the mid atlantic [hot,humid summers,cold humid winters] and it turned freely when I kicked it. You could see where the rings had been sitting looking through the plug hole but it had decent compression and didn't smoke or use much oil after I got it running. So if yours turns without great effort it should likely run once you get the carbs and fuel tank sorted. Your biggest concern will be the carbs and if they are full of the brownish white crud in the float bowls and jet/ passages. That stuff is a royal PITA to get out of the carb bodies.

acceler
Cucciolo - the Lil Pup
Posts: 5
Joined: Tue Nov 05, 2013 10:33 am
Location: Austin Texas USA

Re: Waking up a Darmah

Post by acceler » Wed Mar 09, 2016 4:33 pm

fired my 78 darmah barn find up that had sat since 1987 with no problems. over 25 years that bike sat in a barn. put a battery and fresh gas in it and it fired up within a few seconds and sat there idling perfectly. couldn't rev due to all the frozen cables but she did sound nice idling.
that was after the bee nest and dust blew outta the pipes. covered the back wall of my garage. lol ^>^

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