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Will not start!

eyhonda
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Will not start!

Post by eyhonda » Fri Nov 13, 2009 12:25 pm

I had thought I covered everything before I tried firing it up. But it won't start! I have compression, fuel, spark & timing. No a single pop. A little smoke comes out but that's it. Any ideas or anything I may have missed?
63 cb77 cafe
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Superchicken
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Post by Superchicken » Fri Nov 13, 2009 7:40 pm

first thing, I would do, is turn off the fuel petcock, and then remove one of the float bowls. It will show if you really have gas. Those bowl gaskets are easy to touch the float, then no fuel.

Gunner_CAF
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Post by Gunner_CAF » Fri Nov 13, 2009 8:15 pm

Did you use Ed's method for setting the timing and carbs? If not, make sure you do this and take some time to get it right on. If you have compression, fuel, spark, and some smoke, that leaves timing. If your in Detroit and it's cold, you are most likely giving it plenty of choke. Check the plugs to see if they are wet and getting too much fuel.

Gunner

eyhonda
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Post by eyhonda » Fri Nov 13, 2009 9:25 pm

Yes, I went thru the timing faq. It's fine. I open the drain screws to check for gas. It's OK. Two things I think are wrong. One, I set the floats to 26.5mm, which I read on one of the posts. Later, after receiving the BS manuals, I learned that this was the setting for the 22mm carbs. I reset the carbs to 22.5mm but still nothing. I get spark with plugs out. Oh, the voltage drops to 9 or 10 volts while cranking. Is this normal? Pulling the plugs, they are wet and the oil smells like gas from so much cranking. I went ahead and changed it. I think the spark might be weak.

The second thing, the compression numbers was 125 left and 150 right. This was with oil squirted in the cylinder. I then set the crank at TDC and shot compressed air into the cylinders. The right cylinder turned one crank, which I think is normal and the left was only half a crank. The left is pretty weak. If the numbers I'm getting are with oil squirted in, then maybe the rings are bad? Is the compression test supposed to be dry with no oil in it?

One last thing, I set the valve clearances to .002". After reading the manuals, I reset them to .004".

So, now, I think I will just remove the motor and do a rebuild, at least a top end rebuild. Winter is upon us and I think I will just move on and just do the teardown. I was hoping to get it started to see any running problems, especially any transmission issues.
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e3steve
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Post by e3steve » Sat Nov 14, 2009 2:24 am

Ey, compression seems a bit low on one side, but it should still start. Wet plugs indicate no spark. Condenser? An indication of a failing one is lots of arcing at the points when cranking; like, every time they open or close.
Oh, the voltage drops to 9 or 10 volts while cranking. Is this normal?
Yes, more or less. If the motor spins without sounding like it's dragging its feet, then that should be OK.

Try to get it running first, before tearing it down; at least you'll have a datum to work from.

dkwilfert
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Post by dkwilfert » Sat Nov 14, 2009 5:32 am

Also before going into a motor rebuild, I'd suggest trying a new set of spark plugs. These bikes seem to be real sensitive to spark plugs working exactly right or they will not run/run right. If you have everything else set up pretty close, plugs are an easy thing to try and you will need them someday anyway.

jensen
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Post by jensen » Sat Nov 14, 2009 1:34 pm

Hi,

What kind of caps plug caps do you use ?, new modern caps could lead to failure, these plugs caps have another resistance than the ones Honda used in those days, this leads to a weaker spark.

If the spark is weaker and the battery is low, the spark is even weaker. If the voltage to the plug is too low it will give a weak spark outside the engine, but not inside the engine under pressure.

Connect the high tension cord directly to a new set of plugs, install them, and make sure that your battery is charged.

Air + fuel + compression + spark (on the right time) will lead to detonation of the mixture.

If the plugs are wet from petrol, and the timing is correct, and there's compression the engine should show evidence that's alive.

jensen
assembly of Japanese motorcycles requires great peace of mind (Pirsig)

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