Engine hot?

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Aug 30, 2012
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Hi all,
It’s been a while since posting on here.
126 industrial single port motor with a Solex H30/31 PICT carb, and a 205T vacuum distributor, Bosch blue coil. I’ve got a save my bug dipstick temp ‘sensor’ and it doesn’t show as hot only half or three quarters to the contact point.
This year I’ve taken my 70 bus out for short 10 - 30mile trips and it seems to be a bit on the hot side when parking up. The last time I drove it it wanted to die when coming to a stop so had to feather the gas approaching a stop. It also backfired when coasting down a hill in second or third. Once it popped the little pressure plug out, luckily i found it on the tray and pushed it back in. So I did a tune up today, checking the valves (0.15mm) a couple were very slightly tight, timing (static at TDC) was out by 1 degree advanced. Took it for a drive around the block for 5-10 minutes going up a hill and back down pulled nicely but wanted to cut out on stops. So sprayed carb cleaner (didn’t have WD40 or started spray) on carb throttle linkage (there is a very slight wobble when pushing it forward backward when throttle is open), carb to manifold and manifold to head connections. No change in sound or speed. I tightened the carb to manifold nuts slightly and did a compression test.
1-131; 2- 141; 3-132; 4-145.
Seemed not to be able to push down as hard or get in 1 & 3 as easily just used a hand dial with a rubber plug that you push in to the spark plug hole.
Photos of spark plugs (Beru Ultra) below in order as seen from engine bay. They look grey no brown. No.4 is slightly black.
Changed the oil (Halfords classic green 20W-50).
Then took it out to take garden waste to the tip and the cutting out at stops is gone (since tightening the carb base), on downhills coasting only a very slight bubble here and there no real backfire. Drives really nicely and sounds good at idle and revving it.
Read somewhere these engines should be valve gapped at 0.10mm and timed at 7.5BTDC??
If this is correct would it run sounding this good at 0.15mm and 0TDC?
Just wondering is it too lean (jetting of carb, or still a slight vacuum leak) or are valves too tight or timing out?
Thinking the spark plugs look a little too grey?
Cheers me dears7255E106-6F9A-4346-96DF-1CD513B12818.jpegD610BCE8-769E-4BA1-8A4E-30FF31669051.jpeg66B540A8-8D5B-4C90-BA38-210C5ED0CF40.jpeg
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Nope, sounds like you’ve done all the good stuff. The only thing I can think of is because if this little bubble / burble when coasting, I’m thinks you still got leaks here, possibly zoorst leaks or even carb gasket leaks but I’d still spray around the carb/s and look there as well.. last thing in my head is the vac can and pipe up to the carb. Have a bit of a wiggle with the can, and the pipe and the junctions to see if anything changes. Have a blow up AND down your vac pipe and fittings, and last but not least, pull that dissy apart and make sure everything is moving inside nice and smoothly and a bit of lube in there too.

Ozziedog,,,,,,gettin old int they :)
Hi, when I had the same set up as you, up until a few months back, I was timing at 0 deg at idle with Vac connected. Admittedly mine is a B code engine and this was the recommended timing for a Vac only dizzy, so yours maybe different. It never ran hot even on long runs.

I also have my 123 timed the same, 0 at idle, but tweak the advance curve to give a bit more earlier in the curve 👍
I think if you run valve gap at 10mm or even 6mm it will be noisy, that is if it even runs!!

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