Decompression valve problems Ariel NG

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brenton.roy
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Re: Decompression valve problems Ariel NG

Postby brenton.roy » Mon Oct 15, 2012 12:04 pm

Hi William,
There isn't much to add to John's comments but some caution.
The gasket behind the pump must be replaced. It might leak air. If you suspect this is happening, you can use two gaskets.
Wash the pump out carefully in a solvent. Tap the ball bearings into their seats (with a small hammer!)

The original W/NG had ball and spring arrangements to regulate oil pressure (photo is of a '37 NG). This could well be the problem. If you have this setup, undo the bottom nut, not the screw above it. This need to be checked, cleaned and refitted. Again, tap the ball bearing, fairly firmly, (same small hammer). If this isn't working, or the pipe to the rockers is blocked, oil will just go back into the engine.
Put some fine wire through the oil pipe to make sure it is clear.

Sometimes new oil with detergent - like 20/50 ie GTX or similar, will loosen very old oil deposits, especially if the motor hasn't been running for a long time. These can swim around in your oil system, and might cause a problem with the ball valves. If this is the case, it would be a good idea to wash out the oil tank very carefully.
Also put in cheap oil and change it often.

If there is feed to the bottom end, maybe you could squirt some oil into the rockers with an oil can before starting the bike.
This info is in the W/NG and earlier manuals on the club website. http://www.arielownersmcc.co.uk/members ... ide6_7.jpg
http://www.arielownersmcc.co.uk/members ... manual.htm
Brenton
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Postby william.forsth » Sat Oct 27, 2012 2:49 pm

Thanks Breton and all you others,I have the other setup than you have shown on the picture, but one thought struck me, hod do one taka out the connector that the bras pipe is fitted to from the pump?

just gonna fill her up with new oil now and se if I can get it running. What kind of oil do you use? 20w50 or something else. Seems it has to be quite thin to work well?
Last edited by william.forsth on Sat Oct 27, 2012 6:27 pm, edited 1 time in total.
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Postby admin » Sat Oct 27, 2012 3:45 pm

I use straight (monograde) 40 or 50 and change it often. You'll find different opinions though....
My feeling is that without a proper filter, then changing the oil (and flushing the oil tank) is more important that what goes in.
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Postby william.forsth » Sat Oct 27, 2012 6:24 pm

I have a 50 oil right now, it says extra heavy on it and it feels to thick, I gonna try a 15/40 I think, so I get propper circulation, at least in the beginning now when the system needs to be flushed
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Re: Decompression valve problems Ariel NG

Postby william.forsth » Sat Oct 27, 2012 8:26 pm

Eero, how do I get access to the fly wheel easiest? If I am gonna check the flywheel sludge trap! Do I have to take apart the who,e side of the engine?
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Postby brenton.roy » Sat Oct 27, 2012 10:37 pm

William, 15/40 might be a little too thin, but as John said, clean oil is what you need.
To get to the sludge trap, undo the plate under the motor. It's in the flywheel and it looks like a bolt. Part # 1077-33 in this picture http://www.draganfly.co.uk/shop/pi-4563 ... egoryId=75
You might want to take the spark plug out and put the bike in 4th gear. Turn the back wheel until it lines up.
You'll need a tight fitting socket - 7/16 AF will work. It'll probably be very tight.
When you get the filter plug out, as well as cleaning the stuff in it, clean the channel above it as well. You'll need strong wire, or a drill bit.

Just some notes. Don't use a wrong size socket. If you round the head of the trap, you'll stuff it (big repair job, engine out).
It will be tight to undo, so lean on it a bit. Pull straight.
When you have finished, do it up, not over tight, just tight, with a small amount of low strength loctite.

Re the connector - do you mean the pipe outside the motor?
If so, you can't take the stud out, but you can take off the pipe by undoing the domed nut. You'll probably need new washers for either side of the banjo.

If you have cleaned all the oilways, don't forget to clean out the oil tank. There will be crap in there.
Brenton
'51,'56 Squares, '48 VH, '27 Model C, R67/2, Mk IV Le Mans, '06 Super Duke and Ariel projects.

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Postby william.forsth » Sun Oct 28, 2012 7:52 am

Thanks Brenton, I´ll try that.

What I have done so far is

1) Taken apart all the brass pipes and checked them
2) taken off and cleaned the oil tank
3) Changed the oil pump to a new one
4) opened up under the engine, the plate and cleaned the filter

What I have noticed

1) Oil pump does not deliver oil in any direction
2) Old oil still stuck in the return pipes to the oil tank


So I am guessing it has to be the oil pump, but I guess it might be something stuck in a channel somewhere, so the whole system is not able to work.

Gonna go and get some oil now and see what happens

Thanks

W
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Re: Decompression valve problems Ariel NG

Postby keith.hodgenia » Sun Oct 28, 2012 11:48 am

Hi William. You need to go through it step by step.
1. When you remove the oil pump does oil leak out of one of the holes in the inner timing case? If not there is a blockage or you have the supply and return pipes mixed up.
2. With the oil pump removed push and pull the plungers. You should feel it pumping and hear the ball valves snapping on their seats. If not why not?
3. If you have a check valved fitted in the timing case behind the oil pump, is it stuck or blocked?
Having worked your way through these points it should now pump oil. The scavenging side can have its own issues but that is a story for another day.
Most people stick with mono grade oil. Multi grade oil is high detergent, the sludge trap isn't able to remove anything so it just goes round and round.
Stick with it, you will beat it eventually. Keith.

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Postby Simon.Gardiner » Sun Oct 28, 2012 1:22 pm

Every time I've used multigrade I've ended up with a siezed piston, stick with monograde!
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)

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Re: Decompression valve problems Ariel NG

Postby Eero.Korhonen » Mon Oct 29, 2012 9:35 am

I have always used 20W/50 in my VH and it has been worked well.
I check oil circulation by openening oil tank before getting in road.
-Eero
Ariel VH 1954, IZH 350 1962, H-D Sportster Hugger 1992, AOMCC Member 133


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