Sq4 finally completed...

[nevhunter]

it's repairable. Some coils used a good quality pitch surrounding everything, cooling and waterproofing it. It will overheat without something there. Nev

[MARK.WALSH]

Brian
early on my square 4 rebuild the coil leaked all its oil on a crimped seam leaving me stranded.
As for engine missing - sometimes partially blocked jets or ht leads touching the head and melting the insulation. sometimes just a wipe on the inside of the ht cap can pay dividends if it hunts on tickover. I use B6HS plugs and they are always a bit on the black side of normal unless I go for a fast run. - I don't like the idea of white plugs you describe..
keep working at it, when these bikes settle down they are great to ride
Mark

[simon.holyfield]

Definitely true Mark. Mine has just turned away from the main roads after a 60 mph run up from Norwich, to the coast:

Great bike.

[simon.holyfield]

An eye test gave me an excuse for a trip to the city yesterday: not a particularly nice day, but the SQ4 has not been out for a bit so it was time to stretch her legs. I chose an A-road route outward, with 60 mph stretches for several miles and she is flying along; a mixed A & B-road route back gave me more of the same with some twisties and peaceful roads at the end.

In town traffic, in the morning, you can feel that she's not happy. She gets hot, and the carburation appears rough - not too bad to be called a misfire but not relaxing either. Arriving home, I noticed the same arriving in our small seaside town, and you can see oil on the HT leads so perhaps this is not carburation at all. The clutch also starts to drag a little, so maybe some adjustment there.

At the start of the trip, the early morning starting ritual revealed the carburetter flooding: switching off, starting the engine, and switching on again, the flood did not repeat itself - I think the float sticks occasionally.

On the road, my 28/24 psi front/rear tyre pressure combination may be questionable. The front end feels light and not terribly planted - I may need to reduce the pressure on the front. The bike wants to drift to the side of the road so I think I will look at the wheel alignment.

Stopping to pick up some Argon on the way back (The TIG welder is hungry again) I noticed a slight clonk when moving the handlebars - this may not come from the front end, but needs investigating. The wheel and head bearings are good; the forks have been rebushed.

I also noticed a little oil leak, two in fact - both from the primary drive, one at the clutch and one at the front. The chain is also not getting any lubricant from the primary case oil feed.

I had the LED headlamp on all the way back - it's nice to see the bike balances charge in town with this fitted. Not so nice was the flickering rear lamp apparent with the bike idling, when I took these pictures.

So, a few little jobs (including the perpetual speedo fault) but generally a grand day out. I must have been going some, because my shoulders ache this morning!

[paul.jameson]

What plugs are you using Simes and what do they look like when you take them out? The symptoms you describe are very much those I had at the end of last year on my Square and I have changed plugs to try to overcome the problem. I haven't done enough miles on it so far this year to find out if I have been successful.

[simon.holyfield]

I'm pretty sure that I have a set of NGK B5HS in at the moment. I changed them from B6HS which were sooting up.

I'll have a look in a bit. I've not had them out yet.

[MARK.WALSH]

I was thinking more of reducing the idle jet size as I take my bike off choke in less than a minute and feel some hesitation when hot until I go to main jet,
Some of the old literature talks about this and it would make sense if the plugs are okay at higher speeds (assuming timing is set right)

cheers
Mark