oil overflow and idle problem

[jmontague]

Looking for some guidance on what seems straightforward issues. I am new to the Ariel but not to bikes. I recently took delivery of a restored SQ4 MK2 and have a few teething problems.

I added the 8 pints(imp.) oil and after about 5 mins of running I had oil leaking from the breather tube and out from the cap of the oil tank. I'm wondering whether this is simply too much oil or there is a blockage of some kind ? Either way I am reluctant to run her as I feel I may be damaging her? Not sure what to do other than drain the oil and go with 7 pints.

Unfortunately the throttle cable snapped and I have replaced that courtesy of Draganfly however the the throttle twist grip does not return to the idle position. It is as if there is no throttle return spring. There is a screw on the bottom of the twist grip housing with a locking nut. when tightened the twist grip will not turn. What is this for ? My other question is two fold, where is the throttle return spring and how do I adjust the idle ?

Thank you in advance

Best,
James

[Knud.Degnbol]

I'm amazed.
In my opinion it's normal for old bikes not to close the throttle, when you are making a signal to turn right. How would you else do it?
It is supposed to be like that.


And perhaps your engine have just wetsumped. That's not uncommon for a Mk2 with a gearpump.

[MARK.WALSH]

James
the bike will hold 8 pints but when you refill her it will only take 7 pints (and a bit more) because oil will be sitting in different parts of the engine such as the timing cover and other places where it pools.(making up the 8 pints) As long as the oil flows back you are generally okay. The reason the level rises is probably oil in the sump going back to the main tank causing it to be overfilled. I assume your new bike has not been stood up for some time as the only potential blockages could be the crankshaft feeds being restricted.
As for the throttle - cant answer that one as I assume its an SU as opposed to a solex (which I have)
I would have expected a spring return on the cable - either post a picture of your set up or try looking at some square 4 MK2 pics on google to see if your bike has an incorrect set up
Mark

[paul.jameson]

James,

Take the timing cover off and see what the oil pump looks like. If it it flattish and says MORGO on it, be relieved. If it is rounded with no name on it, then PM me with details of whoever restored the bike. The issue is whether the restorer cleaned out the sludge traps in the flywheels. Any competent restorer would clean out the sludge traps but would almost certainly fit a Morgo pump. If the restorer has fitted an original pump, that indicates cutting of corners and hence the sludge traps may not have been cleaned out. A Morgo pump will not wet sump but an original pump will.

Is the inside of the timing case clean enough to eat your dinner off? If so, this indicates competence, but if it is generally black in colour then you need to worry AND DO NOT RUN THE ENGINE AGAIN UNTIL YOU HAVE CHECKED THE SLUDGE TRAPS.

Ignore this warning and expect your con-rod to exit your crankcases, thus wrecking your engine, in the very near future.

[jmontague]

Right, there is a " throttle return spring " but appears to not have enough "spring" to return the throttle. Wondering if it needs replacing, think i located now. Still not sure how to adjust the idle prior to the throttle cable snapping it was idling just fine.

The oil, I'm just not sure, I was under the impression it was a dry sump

[roland robinson]

James,
Reading through your posts I get the impression that you have not had many dealings with old bikes. I would humbly suggest that you request an experienced Sq4 owner near you to come and give you some guidance. You will of course eventually pick up all the info off this forum but it takes time as you find all the foibles. Give us your location, you can see where Paul and myself live, and make a request.
All the best with your new aquisition, they are a good ride.
Roland.

[simon.holyfield]

Right, there is a " throttle return spring " but appears to not have enough "spring" to return the throttle. Wondering if it needs replacing, think i located now. Still not sure how to adjust the idle prior to the throttle cable snapping it was idling just fine.

Can you post a picture? If you have a Solex, it uses a volute spring. I've had a few problems in that direction.

[alan.moore]

There is a screw on the bottom of the twist grip housing with a locking nut. when tightened the twist grip will not turn. What is this for ?

James,
This is a 'friction' screw. When you tighten it the screw pushes a strip of metal against the 'drum' the throttle cable sits in. The idea is that you adjust the screw just enough to hold the throttle twistgrip in place / stop it returning to the closed position when you take your hand off to signal. If you unscrew this screw the throttle should return / rotate easily. If you remove the cable at the carb end you should be able to adjust this screw and feel how it restricts free twistgrip movement as it is progressively tightened. If the twistgrip is not completely free with the screw backed fully off check the metal strip inside the twistgrip housing is not distorted.

Regarding no idle it is possible that the old cable length was such that it was setting the idle speed. If your new cable inner is even slightly longer the setting will now be out. There should be adjusters on the cable itself.....use these to give maybe an 1/8th inch of free play in the cable before it starts to operate the throttle in the carb. Then set tickover speed with the relevant adjusting screw on the carb.

Post some pics of the carb on the forum (there is a 'how to' guide here http://forum.arielownersmcc.com/viewt ... =35&t=4735)
Cheers
Alan

[jmontague]

Alan

Thank you, I just wasn't sure what the friction screw was for and know little about vintage bikes but know enough not to assume! Thank you for the clarification.

I included a picture of an SU carb on a 1957 Sq4 mk2 (not mine), you can see a spring between the throttle linkage on the carb and the throttle cable stop. I was researching 57's on the web to see if I was indeed missing a spring to help the throttle return and found this video which i took a screen shot of. Was this spring standard or an afterthought you think ?

I do have an adjuster on the new cable which is at its maximum (bought from Draganfly), I have no play so will adjust so I hav as you suggest.

[alan.moore]

James,
I have no first hand knowledge of the Su on a Sq4 but I am sure the chaps who have them will reply and help you out. On cars the return spring is normally around the throttle spindle so maybe the spring on the cable in your post is an addition...someone on the forum will know.

I did find this webpage http://joecurto.com/ariel-square-four-m ... u-mc2-carb which shows the spindle coil spring (last image) and the idle adjuster (last but one image... the knurled slotted screw with the spring under it). With the cable set so that there is some free play the knurled screw is turned in to raise the idle.
Also see the page on the Draganfly website https://www.draganfly.co.uk/index.php/a ... rburetters

Cheers
Alan