Help with tuning.

Matt Spencer said:

" I will check timing again in the AM. "

Check howfar a spark jumps , from a scredriver ? in the plug cap . If it aint 6 mm it aint gunna work , unner load . Pshaw .

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You really should stay off that stuff Matt!

B+Bogus said:

All the coil advice is interesting, but given the symptoms are one side only I'd venture to suggest the ignition/coils etc are unlikely to be the problem?

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He asked one question but has two problems. I'm sure the ignition system is not causing the oil smoke, but coils can cause the poor running. Assuming the poor running is the same as before he changed the coils, then they are probably eliminated. Still, even in an electronic ignition with two coils wired in series, one coil can cause its side to run poorly.

...and the engine not coming down to a proper idle is telling.
None of the engines I've ever rebuilt smoked like that.
I rescued a local shops failed attempt at rebuild, that T150 was smoking bad.
OP, tell us about the pistons, rings, bore sizes.

I can't claim to be able to read your plugs. Why not swap in a pair of new plugs - maybe just standard design NGKs or Champions. If that cures your problem - great. If it cures it for a while, but then it comes back - pretty much confirms you have an oil problem from rings, valves or rocker shaft. Alternatively, if you think it's a coil problem you could swap in a set with the same voltage from another bike.

Pure guess work on my part as most forum advice is. That right side plug looks fuel fouled to me. Skinny electrode and ground are fully black. Not firing every time. Explains the misfire.

Are you sure all the electrical components are talking to each other without excessive EMI or an intermittent short somewhere? Go over your grounds. The more the merrier with grounding and EI.

You could just have a bad plug. It happens.

I am compelled to say just run it some more as already suggested. The rings are a long way from bedded in with only 5 miles on a new motor.

My motor took a lot of miles to get the rings to bed in. They finally did after way more miles that I will list here.

If pump gas fuel was left in the bowls, two years is a long time, and the fuel will more than likely have evaporated and left a chalky residue that is a pain in the butt to clean out. You probably already addressed it, but just mentioning it.

I don't know what plugs you are running. But if not running the resistor caps and non-resistor plugs, you could try a slightly hotter resistor plug that I know works. You can take them out after you ensure the motor runs on both cylinders and have put a few mild miles on the engine. I use Autolite APP 3924 plugs. Small 5/8ths plug wrench plug. You can get the equivalent plug in a 13/16th wrench size, but I don't know what part the number is off the top of my head. The APP 3924 plugs are cheaper than what you are using and good for troubleshooting.

By the way, there should be some Norton members near you in Oregon. A second set of eyes on the prize might help.

Sorry about the babble, but you did ask for help. Be careful what you wish for.

If the motor is very loose and oily, the next lower heat range in spark plugs might help. If you are using NGK9 go to NGK8.

Al, or anybody really, how about a definition for a poor uneducated guy like myself?

Is a lower heat range plug about the heat a plug produces holds transfers (less heat), or the engine characteristic being addressed by the plug? For example, does an engine that runs too cold need a colder heat range plug because the colder range plug produces holds transfers more heat into the combustion chamber for a better burn?

I have a feeling that I have the heat range definition reversed in my head and have ever since I figured out what a spark plug is.

By the way, I have tried to find the answer on the web on occasion, but still can't get a simple answer.

Colder plugs are for use under more severe heat conditions (hotter) in the combustion chamber.

Also called “harder” plugs.

acotrel said:

If the motor is very loose and oily, the next lower heat range in spark plugs might help. If you are using NGK9 go to NGK8.

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Interesting. The shop that just did my bikes first overbore put in NGK8's, so cooler than the 7's most recommend. Will run these for first few hundred miles of break in period and see how they go.

Schwany said:

Al, or anybody really, how about a definition for a poor uneducated guy like myself?

Is a lower heat range plug about the heat a plug produces holds transfers (less heat), or the engine characteristic being addressed by the plug? For example, does an engine that runs too cold need a colder heat range plug because the colder range plug produces holds transfers more heat into the combustion chamber for a better burn?

I have a feeling that I have the heat range definition reversed in my head and have ever since I figured out what a spark plug is.

By the way, I have tried to find the answer on the web on occasion, but still can't get a simple answer.

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My understanding is heat range determines the operating temp of the plug electrodes. A higher temp rating means the plug is designed to shed less heat, keeping electrodes hotter for better self cleaning. A cooler rating means more shedding and lower electrode temp, less self cleaning but better protection from electrode degradation, better longevity.

Triton Thrasher said:

Colder plugs are for use under more severe heat conditions (hotter) in the combustion chamber.

Also called “harder” plugs.

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Tornado said:

My understanding is heat range determines the operating temp of the plug electrodes. A higher temp rating means the plug is designed to shed less heat, keeping electrodes hotter for better self cleaning. A cooler rating means more shedding and lower electrode temp, less self cleaning but better protection from electrode degradation, better longevity.

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Thanks

Apparently, I've known all along. My example was the opposite of what I thought was how it all worked intentionally, since I (right or wrong) would use a higher heat range plug in an oil burner. Al made me think I must be confused with his colder plug advice.

Probably covered under other misfiring scenarios

Carburetion synchronization not correct
float height to high too low
float needle deterioration
Needle clip positions not the same
idle mixtures way off

Last but not least that damn o-ring seal at the carburetor flange. Why? I know most of youz guys adore it, but I never understood that lawn mower design feature.

Had the same problem with my combat after engine rebuild by a “professional shop”!
finally I pulled it apart and found oil expansion ring was overlapped and not putting enough pressure on oil rings. It’s now running perfectly. Check for oil at end of exhaust.

Generally when I have found the need for "hotter" plugs (plugs that have a longer cooling path resulting in more retained heat) was when cam timing or other tuning requirements resulted in a richer than ideal A/F ratio at low-mid range RPMs. "Hotter" plugs resist fuel fouling better by burning off soot that might otherwise foul the plugs while operating in traffic or other part throttle conditions. My 86 cu in Panhead stroker benefitted from "Splitfire" plugs that had a forked ground electrode. I could run a slightly colder "splitfire" and prevent fouling better than a standard 14Y Champion plug while being less prone to detonation. That was the only time I saw any advantage over regular copper plugs in any hopped up internal combustion engine. The old Pan had lots of cam lobe overlap and ran a bit lumpy at idle.

The tradeoff is that "hotter" plugs can cause detonation so a balancing act is required. Too "cold" and plug fouling can be an issue. Too "hot" and detonation can become an altogether different problem.

Hot plugs are also useful to prevent oil fouling. I once ran a Champion 14Y plug in a Briggs & Stratton roto-tiller engine that burned oil so bad you had to stop and top off the oil 2X for every tankful of gasoline. (fill her up with oil and check the gas) Eventually the ash from the burned oil would bridge the gap of the plug and require periodic cleaning.

Thank you everyone for your input. Running much better today. As you can see I cant run it around the block, its snowing and the roads are icy. Oil smoke has miraculously disappeared. Must be the new plugs as nothing else changed. The right side pipe has oil in it as it is weeping out the silencer connection and head.

Carbs are synchronized but ill wait till I can run it on the road to fine tune. I have put together a few engine but nothing has smoked like this.

https://youtu.be/o1w15NeHF7M

marshg246 said:

He asked one question but has two problems. I'm sure the ignition system is not causing the oil smoke, but coils can cause the poor running. Assuming the poor running is the same as before he changed the coils, then they are probably eliminated. Still, even in an electronic ignition with two coils wired in series, one coil can cause its side to run poorly.

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I had a couple of new old school Champion N7YC plugs. I did swap the coils side to side. Timing was right on mark @ 31 Degrees @3500RPM

Schwany said:

If pump gas fuel was left in the bowls, two years is a long time, and the fuel will more than likely have evaporated and left a chalky residue that is a pain in the butt to clean out. You probably already addressed it, but just mentioning it.

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The Carbs are rebuilt, last month, stay up, viton, new needles ,new jets, pilot air cleaned out. Chokes removed.

concours said:

OP, tell us about the pistons, rings, bore sizes.

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Pistons JCC+20, Rings are Hastings, I had Franz and Grubb in Socal bore the barrels with the pistons in hand. Cam is a JS1 with radiused followers. Head by Comnoz,

Right plug fouled badly. On a JC done head, I wouldn't think guides are bad.

Have you checked torque on head?

L plug looks lean. Also looks too hot, but that could be from running lean.

Heat Range = Ground Strap, the ground strap indicates the heat-range of the spark plug. If the "color" of the ground strap "changes" too close to the ground strap's end, (which is above the center electrode), then the heat-range is "too cold", meaning that the strap is loosing heat too quickly to the base ring, and is not able to burn off deposits until near its end.

If the "color" of the strap changes near where it is welded/attached to the base ring (last thread ring), then it means that the plug heat-range is "too hot", because heat is not being transferred/cooled from the strap to the base ring quickly enough !!!! The strap might begin to act like a "glow-plug", eventually causing preignition and/or detonation later on.

Proper heat-range is when the "color" is at the halfway point on the strap, neither too cold or too hot.

(Color = meaning the evidence of heat/or lack of heat by the appearance dark vs lightened color of metal)

A NGK BP7ES is hotter than a BP8ES.

A Champion N7YC is hotter than a N6YC.

Their part numbers are numerically opposite.

​

Not everyone has had good experiences with Hastings rings.
Wassells, the UK supplier of 'Hepolite' branded piston kits stopped supplying Hastings rings a few years back and now supply AE/Goetze rings.
Your bike now seems to be running as well as any high-tune motor which just needs a few final tweaks. My guess is the oil was due likely due to wet-sumping after a prolonged rest period.

B+Bogus said:

Not everyone has had good experiences with Hastings rings.
Wassells, the UK supplier of 'Hepolite' branded piston kits stopped supplying Hastings rings a few years back and now supply AE/Goetze rings.

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I removed the top end to replace the (new) Goetze rings, mainly for the one piece oil scraper ring. (With Hastings / three piece scraper pack)
There is something not right about the coil expander (imho), the ring tension once they are in place is extremely high due to that expander to the point they are quite hard to fit into the bore (The compression rings were fine)
Time will tell eventually.
I cut the Goetze expander down around a millimetre at a time as a test and only a 'few mm made all the difference (ring in hand with expander and compress / close the end gap.
A check showed it was not the ring groove base but the high circumference pressure they were applying and I mean crazy high.

The engine on the bench still rotated smoothly without noticeable drag but it played on my mind for some time including the new alloy KW push rods (that were also replaced)

The Hastings rings seemed more acceptable (to me based on a lot of rings in general over the last 40 years or so) but bore finish and running in might have some influence.
Maybe it will be a smoker straight off the bat.

"

concours said:

OP, tell us about the pistons, rings, bore sizes.

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Pistons JCC+20, Rings are Hastings, I had Franz and Grubb in Socal bore the barrels with the pistons in hand. Cam is a JS1 with radiused followers. Head by Comnoz,"

Hastings... are the oil rings ONE piece, or THREE piece?

Time Warp said:

I removed the top end to replace the (new) Goetze rings, mainly for the one piece oil scraper ring. (With Hastings / three piece scraper pack)
There is something not right about the coil expander (imho), the ring tension once they are in place is extremely high due to that expander to the point they are quite hard to fit into the bore (The compression rings were fine)
Time will tell eventually.
I cut the Goetze expander down around a millimetre at a time as a test and only a 'few mm made all the difference (ring in hand with expander and compress / close the end gap.
A check showed it was not the ring groove base but the high circumference pressure they were applying and I mean crazy high.

The engine on the bench still rotated smoothly without noticeable drag but it played on my mind for some time including the new alloy KW push rods (that were also replaced)

The Hastings rings seemed more acceptable (to me based on a lot of rings in general over the last 40 years or so) but bore finish and running in might have some influence.
Maybe it will be a smoker straight off the bat.

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You make me wonder if I could have the same problem , as for the first time I will have to deal with those Goetze rings in a new 750 barrel , I had checked the ring gaps of the two upper rings all is ok , then after your post I had tried to fit the piston with the oil controll one in the barrel and just like you , it was pretty tight , so I stop where i was and will see later , previously I allways use hastings ( dozen of engines )and yes they were tight but when fitted (never file the gap ) no problem .........so , may be I will use a ring compressor that I don't have , as i had all ways use my fingers !!!