Author Topic: No combustion Help  (Read 1944 times)

Burntsteel

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No combustion Help
« on: April 13, 2020, 10:59:04 AM »
Ok guys, Im a newbie to this but I inherited my grandfathers bike that is all original and is one owner(grandfather).  My dad has over the years tried to work and ride this bike but without questioning my father I have decided to start fresh.

Not sure of the year bike I have, I think it is an "M" model.  Serial Number M22118B  stamped below the crank cover.

Anyway:
i set new points at .013 gap. 
I have a J17L spark plug which is currently gapped at .020
I am getting good spark but I can't seem to fire off starter fluid or gas/oil mix, Compression is good what am I doing wrong

My questions are :
What is the correct spark plug number
with running only one plug what are your recommended gaps on both points and plug

I am using 6volt coil from dennis carpenter for WICO

Any help would be appreciated.

.

Ricks

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Re: No combustion Help
« Reply #1 on: April 13, 2020, 11:43:10 AM »
Points are too tight, should be gapped at .020.  This is printed inside on the magneto backing plate.

I tried looking up a J17L plug, but could not find any specs on it, but if it is a champion, 17 heat range is really hot.  I have used Champion J8C with success.

My preferred spark plug is Autolite 295.

Did you take a compression test?  You should have at least 70 lbs of compression.
Rick

Burntsteel

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Re: No combustion Help
« Reply #2 on: April 13, 2020, 12:32:40 PM »
Thank you Rick,  I originally had them set at .020 but wasn't getting any fire. so I backed them down, just dawned on me I also changed the non-working condensor and that is when I started getting fire.
So in response,

Re-gap my points to .020
change to a J8C plug or Autolite 295 and gap at........? .035?

no compression test yet, but it has enough to make me want to rethink pushing the kickstarter with my hand. but I will check it.

Mainly what I am looking for is that 2-5 seconds of running off starter fluid to know it will run then move to new carb and fuel delivery 

Thank you for your input I greatly appreciate it.

Ricks

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Re: No combustion Help
« Reply #3 on: April 13, 2020, 01:43:12 PM »
Gap the plugs to .025.  A motor with good compression will be really hard to start by hand.
Rick

Burntsteel

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Re: No combustion Help
« Reply #4 on: April 13, 2020, 02:44:45 PM »
Local auto parts didnt have autolites or j8c they had the E3 more expensive J8c equivalent.  Regapped point to .020 and gapped plug to .025.    Still no change. Still is firing with plug out of cylinder but not igniting gas or starter fluid.

Ricks

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Re: No combustion Help
« Reply #5 on: April 13, 2020, 02:58:14 PM »
Post a couple of pictures of the motor.  Do you have the compression plate installed?  Is there a seal under the motor pulley?  It sounds like you are not getting fuel transfer from the crankcase to the combustion chamber.
Rick

Burntsteel

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Re: No combustion Help
« Reply #6 on: April 13, 2020, 03:08:35 PM »
Squiring fluids in the spark plug hole 

Ricks

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Re: No combustion Help
« Reply #7 on: April 13, 2020, 05:13:28 PM »
Is the throttle hooked up?  If not, is the throttle plate open to allow air in? Squirt some starting fluid in the carburetor and then give a kick.

If the above gives nothing, remove the side cover. Under that should be a compression plate.  Without a compression plate, it will never run.

Did you do a compression test?
Rick

Burntsteel

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Re: No combustion Help
« Reply #8 on: April 13, 2020, 05:52:28 PM »
Spoke to Mr Mahaffey  yes compression plate is in. Crankcase was full of fluids so i cleaned it. He also told me to seal off the hole at the carb going to motor  havent dont that yet.  Waiting on new carb to get here so the original is still on and worthless. Has no seals.  I am squirting directly into the head and if i pull a plug and turn it over i have a wonderful fire show. But with both plugs in i cant seem to get a combustion fire.   Again this thing hasnt been cranked in at least 35 years. So im sure there are more seals or something im missing.   Still no compression test

Ricks

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Re: No combustion Help
« Reply #9 on: April 14, 2020, 04:03:08 AM »
Was the motor taken apart and put back together? The piston on these motors has a slant on it, and only works when the slant is pointed at the exhaust side of the motor.  Pull off the exhaust manifold, and slowly turn over the motor. You can see inside the exhaust port and make sure the piston is installed correctly.
Rick

Burntsteel

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Re: No combustion Help
« Reply #10 on: April 14, 2020, 05:32:43 PM »
Okay no progression so i pulled the head. Current piston is 010 clean airways  rings look good.  Also have a std piston and head should i swap these? Doesnt look like any blowby is occuring

Ricks

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Re: No combustion Help
« Reply #11 on: April 15, 2020, 05:17:16 AM »
Take the rings off and measure the gap. I'd bet the rings are shot.  Ring gap should be .008-.010.

What's your name and where do you live?


Rick

Burntsteel

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Re: No combustion Help
« Reply #12 on: April 15, 2020, 06:27:02 AM »
Mike McCollum.  Athens Ga

Burntsteel

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Re: No combustion Help
« Reply #13 on: April 15, 2020, 06:36:20 AM »
Its almost like when i put both plugs in it smothers or “chokes” any air from getting in the cylinder. When I take one plug out i have fire and combustion. Really odd.



And looking at the rings I don’t see any blow by, but i will measure them later this evening.

Burntsteel

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Re: No combustion Help
« Reply #14 on: April 15, 2020, 03:28:37 PM »
Great news   Yay yay yay.  She fired off and ran for about 2 seconds. 

When i put the cylinder head back on i made sure the ring gaps were offset   Which i think was the problem.    Added a cap full of mystery oil and couple cc’s of fuel.  First kick.   Makes me very happy.  Rick thank you for your assistance   Still not done but this hurdle seems to be out of the way