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luckydevil
12th July 2005, 21:52
I bought a hotter set of plugs. 4R instead of 4R5.
The guy at the dealership warned me about getting to hot.
He said be careful or i might burn a hole in my piston.
Really?
I did not think that was possible with a spark plug.
waja think?

883 custom
12th July 2005, 22:00
Why get a hotter plug? If it was running good with the other plugs I would not switch them. Not real sure about the hole in piston thing, guess it could happen. What you want is for the electrod on the plug to burn half and half, in other words the electrode will be black towards the threads and burn clean near the tip. Hope I didnt confuse you.

luckydevil
12th July 2005, 22:24
I bought em cause my bike was hard to start after a ride.
Let it sit for twenty and it won't wake up.
It just sits there and pops in the pipes or the carb
Every thing else seemed good.
Plugs have a bit a black on em. but no carbon smoke or bog.
The bendix pulls strong and smooth from idle up to 5000.

it's a 75 if that matters.

883 custom
12th July 2005, 22:30
Hmmm...if its popping in the pipes when trying to crank it is rich or "bleeding" past the seats. Try holding the throttle(not pumping) open abit and see if that helps. If the electrode is burning half and half that is the correct heat range for the engine.

luckydevil
12th July 2005, 22:43
The electrode is mostly black.
That means rich.
I live in broomfield colorado.
I have an ajustable main.

i don't want to lean it out too much i KNOW that burns pistons.

IronMick
13th July 2005, 00:55
I use a hotter plug in my rear cyl to burn off the carbon buildup. NGK6 in the front, NGK5 in the rear. With NGK the lower number is the hotter plug. This allows me to set the mixture rich enough that the front plug is gray to tan instead of white to gray [or just plain white!]. The rear plug is quite dark by comparison.

dabronco
13th July 2005, 01:48
If ya use too hot a plug, it can pre-ignite and that will BLOW a hole in a piston. Most bikes can take a few more cranks to start after a heat soak. The fuel wants to vaporize instead of atomize. Also the oil is thinner and doesn't seal the rings as well. Kick it thru with the throttle more open than normal a couple times. (Or crank it) Then close the throttle to your normal position. Some times all mine needs is a couple twists of the loud handle and hit the starter. Sometimes the fuel in the carb bowl evaporates some, (if you shut the gas off when you stop) and just turning the gas on a minute earlier while you get yer helmet on, works.

luckydevil
13th July 2005, 21:36
I do notice a little better burn on the front.
I will try mixing it up when i get it starting.

Does plug heat change head running temp at all?
Would going colder lower the operating temp?

I have tried all kinds of throttle positions.
twist + twist and hold works when cold.
The only one that worked hot is wide open, same as a flooded engine.
That only worked once.
The timing is good.

If the idle was too lean, and the main too rich?
Would it make it hard to start hot without flooding?

dabronco
13th July 2005, 21:42
They's all different man. It's hard to diagnose jetting with a starting problem.

luckydevil
13th July 2005, 21:51
Yeah.
I hoped not.
I'll just keep trying.
Change something: ride: wait: start
Change something else: ride: wait: start
Again
Again
At least i have an excuse to ride.

IronMick
14th July 2005, 04:24
I bought em cause my bike was hard to start after a ride.
Let it sit for twenty and it won't wake up.
It just sits there and pops in the pipes or the carb
Every thing else seemed good.
Plugs have a bit a black on em. but no carbon smoke or bog.
The bendix pulls strong and smooth from idle up to 5000.

it's a 75 if that matters.

First things to check, from my experience are the pushrod adjustments and air leaks. If any of the p-rods is out of adjustment you cannot get a good tuneup. If there is air leak at the intake manifold or at the exhaust headers also you cannot get a good tuneup.

To check for air leaks at the intakes spray WD40 on the joints while the engine is running. If the idle speed changes while you are spraying there is a leak.

To check for exhaust system leaks put 1/2 ounce of any oil into each cylinder, start 'er up, and watch where the smoke comes from. It will take 5 to 10 minutes of running to burn off that oil so you have lots of time to look around.