78' SE...Mystified...post tune up...

[Mojodad]

Mystified... done a tune up on the 78'SE...
All done by the book, in sequence, had it running, replaced points, timing done, (dead on) new plugs @.0030"...
Timed with light, at first it did idle down well enough to set timing right on at 1200rmp... then had issue with low idle, would surge and stall.
Okay no problems, I have a carb issue, it would run alright @3000 had it running alright in the shop for 7-8 mins with 2 fans on the 650...
I shut the bike down, next day I go to start the the bike and no go...nothing and nothing since...
I drained the tank, fresh gas, spark to both points, spark to both plugs, new battery voltage up...
So what does a Guy do?...start from scratch, double and triple checked everything...
Getting fuel, spark, reset the timing with multimeter but its not even giving me a hint at starting, when I had it running (decent) after tune up...

Would appreciate advice on what to look for next...

(At this point I'm convinced there are Gremlins in the hiding in the shop, all I did was turn the bike off...)

 

[TwoManyXS1Bs]

... new plugs @.0030"...

I certainly hope that's an extra zero in there. 0.025" may be a better starting place.

Time to read the plugs. Do a start attempt, immediately pull the plugs.

If wet, too much choke/fuel. Clean/dry them, turn fuel off, open throttle, kick-thru several times, reinstall plugs, retry without choke.

If dry, probably clogged pilot jets, or enrichener problem...

 

[retiredgentleman]

If your feeler gauges had some oil on them, they may have contaminated the points. Try cleaning the points..............maybe drag a piecs of paper, with some contact cleaner on it, between the points.

I would also use a VOM to measure the resistance of both sets of points. They need to read 0.0 ohms when closed.

 

[fredintoon]

Hi Mojodad,
.003" vs .030", eh?
Us bodgers don't need no steenkin' feeler gauge to check the plug gap.
Nature has already given you one.
Shove your thumbnail in there.
That's close enough that the bike will happily run on it.
But only if you've fixed the real problem.

 

[Mojodad]

Thanks all...
I'll dress/clean up the points again, their at 13-14 thou' and getting spark to both...(both reading 0 when closed)
plugs at 30 thou' (I'll forget the decimals from now on and getting good spark to both when out...
Back to the Gremlin story...
Reading the plugs...right side carboned up... I pulled the carbs, cleaned all, there was an issue with the right side choke plunger, seemed it was not completly coming off (re-seating) left side fine, this could explain the right side rich running.?..
pilot screws out and cleaned, all open...re-set them to 2 1/4 out...
re-checked the floats to 24mm, new fuel and vac lines...
I'll be going back at the bike later on today...

 

[Mojodad]

Yeah...
Thinking I'm into bigger problems, still not a hint at starting, compression low, will re-check with a better gauge...
Seems I'm looking at a top end re-build here...

 

[TwoManyXS1Bs]

There's the rare outside chance that a (or more) valve(s) stuck in the guide(s), and you set your valve clearances for stuck (non-seating) valve(s).

A quick test/fix is to reset your valve clearances really loose, say about 0.030"-0.050", and attempt a restart. Then, later, set your valves to 0.003" Intake, 0.006" Exhaust...