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by berniejones
Thu Jun 21, 2018 7:56 am
Forum: Four stroke
Topic: Recurring weak spark SQ4 Mk2
Replies: 3
Views: 609

Recurring weak spark SQ4 Mk2

Since my rebuild I've had a number of experiences of difficulty or failure to start which I've traced to a weak spark. Each time I've replaced the coil and the problem has been solved for a while but then seems to reoccur. I've tried new Lucas and others and also some old Lucas originals from other ...
by berniejones
Wed Jun 13, 2018 2:18 pm
Forum: Four stroke
Topic: SQ(ueek) 4 !
Replies: 11
Views: 1254

Re: SQ(ueek) 4 !

Well, it wasn't an air leak at all. Current suspicion is a dry LHS exhaust rocker. Running the engine with the rocker covers off I'm getting healthy dripos from both RHS rockers but less from the LHS inlet and hardly anything from the exhaust. It could be a restriction in the feed via the 'U' pipe f...
by berniejones
Tue Jun 12, 2018 8:16 am
Forum: Four stroke
Topic: SQ(ueek) 4 !
Replies: 11
Views: 1254

Re: SQ(ueek) 4 !

Haha! Yes, it takes all sorts! Maybe just as well I was off the river at the w/e as it's Broads hire boat change-over time and it's quite entertaining to watch the game of dodgems as the holidaymakers try to master the controls of boats that they really shouldn't be allowed to drive!! I'll try that ...
by berniejones
Mon Jun 11, 2018 5:44 pm
Forum: Four stroke
Topic: SQ(ueek) 4 !
Replies: 11
Views: 1254

Re: SQ(ueek) 4 !

Hi Simon, it's ihe long inlet pipe from the carb to the head - not sure if the Solex is the same but the SU casting is secured by two bolts at the back and one at the front. Would have taken it for a spin this afternoon but been changing water pump impeller in my Yamaha outboard - would test the pat...
by berniejones
Mon Jun 11, 2018 2:14 pm
Forum: Four stroke
Topic: SQ(ueek) 4 !
Replies: 11
Views: 1254

Re: SQ(ueek) 4 !

I think I tracked it down - seems the thread on the front mounting bolt for the inlet pipe has stripped and the bolt was loose. I think the sound was air being sucked in. It will need a helicoil to fix properly but hopefully my quick bodge with Loctite will last long enough for a test run.... Cheers...
by berniejones
Sat Jun 09, 2018 9:42 am
Forum: Four stroke
Topic: SQ(ueek) 4 !
Replies: 11
Views: 1254

Re: SQ(ueek) 4 !

Thanks Nev - will be first point of call!
by berniejones
Sat Jun 09, 2018 9:09 am
Forum: Four stroke
Topic: SQ(ueek) 4 !
Replies: 11
Views: 1254

SQ(ueek) 4 !

I've now put around 50 miles on the SQ4 since the build and sorted most of the snags. So far so good but after the last short run I can hear a distinct squeaking/squealing sound when idling. It sounds as if it might be the sort of noise a dry bearing could make but I'm not sure where to start lookin...
by berniejones
Thu Mar 29, 2018 8:53 am
Forum: Four stroke
Topic: SQ 4 MkII first start - oil and smoke....
Replies: 27
Views: 3340

Re: SQ 4 MkII first start - oil and smoke....

Thanks Paul, that's very interesting - anything that reduces the level in the sump would be good so I'm wondering if it might be possible to crimp something around the pipe from below after removing the sump plate.... or stretch a piece of silicon tube over the end. Food for thought!

Cheers,
Bernie
by berniejones
Tue Mar 27, 2018 12:26 pm
Forum: Four stroke
Topic: SQ 4 MkII first start - oil and smoke....
Replies: 27
Views: 3340

Re: SQ 4 MkII first start - oil and smoke....

In the end I didn't send the pump off to Morgo as I did my own simple test that seemed to show all was well with it. Similar to what I'm proposing now, I first disconnected the return line and diverted it into a measuring cylinder, ran for 30 secs and recorded the volume of oil returned. This was wi...
by berniejones
Tue Mar 27, 2018 8:44 am
Forum: Four stroke
Topic: SQ 4 MkII first start - oil and smoke....
Replies: 27
Views: 3340

Re: SQ 4 MkII first start - oil and smoke....

It's been a while so I thought I'd update. Spent the winter working through a snagging list including fixing the dynamo, investigating oil leaks and attending to carb issues. Put a few miles on the clock when the sun shone yesterday and no disasters but.... still lots of smoke once warmed up and par...

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