Trouble starting 49mm iron sleeve

[Street Ryderz]

It’s about 1mm from being fully seated but the plug fits so tight at the moment it will not go any further. I would be inclined to think there’s not a big enough loss of compression to cause the problem I’m having because it’s so tight fitting, There are tapered plugs that seal by a similar tight fit vs the crush ring. It’s definitely worth addressing whether it’s the cause of the problem or not. I thought possible the spark plug is not in the optimal position to ignite the air/fuel mixture.
Looks like I’m on hold til the thread chaser comes from Amazon as far as that goes unfortunately my tap set only goes to 12mm.

May run a compression test on it just to see what it says.
As far as the plug heat range, oddly there’s still been some colder days/ more so nights here in Kern County Ca but it’s only going to get warmer. Though, to my knowledge, temperature of the weather has little affect on what heat range plug to use, but more air fuel/ratios, oil/fuel ratios, hi vs lo compression, naturally aspirated/ boosted in 4 strokes, self cleaning ability, among other things … otherwise we’d all be changing plugs two times a year right???

What heat range plug needed can vary from engine to engine depending on the factors I listed above and more so it’s hard to say if you need a colder or hotter plug until you run it long enough to read the plug. But in general a lower compression, relatively low performance/ stock engine generally run warmer plugs.

The plug not being seated with the crush ring WILL lose compression, and hotter plugs make the engines over all temps higher this is a fact and yes if the plug tip isn't in the chamber fully the flame front wont propagate into the chamber correctly thus leaving an incomplete burn to where you will never be able to read the plug and it runs like s**t!

 

[Mc2Stroke]

And where @Mc2Stroke lives in Bakersfield, Ca. It can get as hot as where I am in Alamogordo, NM...I know, I have been there many times back in the early 70s...lol...I found the NGK-BR8HS the best plug for desert conditions.

Yeah it can get pretty hot here, I’m glad it seems to be warming up late this year I can’t stand the heat. I’ve only passed through NM on the 40 a few times but I’ve done it in the summer and it definitely gets hot there too.

Does changing plugs due to weather make a difference?
I’d assume if it were to have any affect it would make more of a difference on an air cooled engine as plug heat range affects how fast heat transfers from the plug to the head.

Is there some benefit I missed by sticking to a plug in the middle of the heat range? If so I sure didn’t notice but it would be nice to know if there is.
Unfortunately I haven’t had a 2 stroke for over 10 years aside from a chainsaw, ive mainly worked on Chevy v8s and there’s only a few reasons I can think of to go with a colder plug and none of them are the weather.

I only really had 2 strokes as a kid- teenager and only a few were air cooled.
( yz125, a ysr50 both off which I really regret trading, a few go peds, and pit bikes and mini bikes) Every since my first 2 stroke go ped I used to just try changing things like spark plugs, fuel mix ratios, I’d take them apart an clean them even though they weren’t dirty haha just so I could teach myself how everything worked and how to fix it. I really wanted to try n make it faster and run as well as possible unfortunately back then I hadn’t learned much about porting and custom pipes and all the other fun stuff.
back then I lived in southern Ca where the weather never really got too hot and rarely got too cold but was just nice year round. I did travel to the desert to ride dirt bikes where there were differences in altitude and definitely temperatures ( usually extreme heat difference) there was only a few I could tell that my bike could have benefited from changing jets, but I’ve never had an issue where it required changing to a different temp spark plug.
Even after moving from southern Ca to a small town in the Mojave desert I never had to change to a different heat range plug.

Sorry for rambling kind of fun reminiscing in the past. I’m also, actually curious to know what and exactly how much changing plug temp for different weather affects anything and is there verifiable proof.

 

[Mc2Stroke]

The plug not being seated with the crush ring WILL lose compression, and hotter plugs make the engines over all temps higher this is a fact and yes if the plug tip isn't in the chamber fully the flame front wont propagate into the chamber correctly thus leaving an incomplete burn to where you will never be able to read the plug and it runs like s**t!

I think in this particular case the compression loss is very minimal I got curious and put some soapy water around the spark plug turned the engine over and looked for bubbles and there’s nothing visible/ and could not hear anything. But I definitely agree there is a case of the spark plug not being completely in the chamber causing part of my problem.

Fact Check* plug temp (hot/ cold or in between) affects on combustion chamber temp is minute and even less the overall engine temp…
higher temp plugs are hot because they transfer less heat from the tip into the cylinder head hold that heat mainly in the plug tip which can get so hot it causes detonation, pre ignition etc. if the conditions are present for that to happen but under the right conditions also does things like help with carbon build up and fouling.

Cooler plugs are cooler because they release more of their heat from the plug tip into the cylinder head faster and more efficiently giving them a “colder tip” which can cause problems too if not used in the correct application.

I appreciate the input

 

[DAMIEN1307]

’m also, actually curious to know what and exactly how much changing plug temp for different weather affects anything and is there verifiable proof.

Nope...lol...No verifiable proof from me...lol...It just does seem to work better for some unknown reason to me, so at a 4500 ft altitude in the high desert of New Mexico, with very low humidity, (Right now it is up to 5%...lol)...about an hour and a half from the Mexican border, thats what I recommend to use as it works extremely well under these conditions for ME...YMMV...lol.

 

[Mc2Stroke]

Nope...lol...No verifiable proof from me...lol...It just does seem to work better for some unknown reason to me, so at a 4500 ft altitude in the high desert of New Mexico, with very low humidity, (Right now it is up to 5%...lol)...about an hour and a half from the Mexican border, thats what I recommend to use as it works extremely well under these conditions for ME...YMMV...lol.

Well in my experience every engine likes something a little different even if they’re built the same with the same parts run in the same area.
I’d say as long as it’s working for you and you’re happy with it then do what works for you.

I might have some insight into why “it works” but my eyes are burning from not sleeping and staring at a phone screen looking at all the things I wish I had money to buy for my bike among other expensive hobbies. My brain is also on reserve and it was hard enough to put together the words to type this.

 

[Mc2Stroke]

Street Ryderz “and it runs like s**t!”

Can’t argue with that part… hahaha

I’ll get it all figured out eventually, for now I’m going to hurry up and wait for this Amazon order so I can at least fix the s**t I know needs fixing.

 

[Street Ryderz]

I think in this particular case the compression loss is very minimal I got curious and put some soapy water around the spark plug turned the engine over and looked for bubbles and there’s nothing visible/ and could not hear anything. But I definitely agree there is a case of the spark plug not being completely in the chamber causing part of my problem.

Fact Check* plug temp (hot/ cold or in between) affects on combustion chamber temp is minute and even less the overall engine temp…
higher temp plugs are hot because they transfer less heat from the tip into the cylinder head hold that heat mainly in the plug tip which can get so hot it causes detonation, pre ignition etc. if the conditions are present for that to happen but under the right conditions also does things like help with carbon build up and fouling.

Cooler plugs are cooler because they release more of their heat from the plug tip into the cylinder head faster and more efficiently giving them a “colder tip” which can cause problems too if not used in the correct application.

I appreciate the input

Think about what your saying, a hotter plug that keeps it's heat at the tip and not the head heats up what?
A colder plug that transfers it's heat to the head does what?
When I've run hotter plugs the engines over all running temps go up with leaps and bounds when monitored with a heat sensor and the stock heads and with larger cooling area aftermarket heads it is still quite the difference one heat range can make.

 

[darwin]

Palm Springs summer.

 

[ImpulseRocket]

Yeah it can get pretty hot here, I’m glad it seems to be warming up late this year I can’t stand the heat. I’ve only passed through NM on the 40 a few times but I’ve done it in the summer and it definitely gets hot there too.

Does changing plugs due to weather make a difference?
I’d assume if it were to have any affect it would make more of a difference on an air cooled engine as plug heat range affects how fast heat transfers from the plug to the head.

Is there some benefit I missed by sticking to a plug in the middle of the heat range? If so I sure didn’t notice but it would be nice to know if there is.
Unfortunately I haven’t had a 2 stroke for over 10 years aside from a chainsaw, ive mainly worked on Chevy v8s and there’s only a few reasons I can think of to go with a colder plug and none of them are the weather.

I can simplify this.

You want to run the plug that is just "hot" enough in heat range to effectively self clean under normal operation. Basically, the coldest plug that still operates without fouling. Self cleaning ability is the reason heat ranges exist. Too hot and you can get pre-ignition. Too cold and you will foul plugs.

You are correct in that heat range of the plug does NOT affect combustion temps or operating temps of the engine directly. If the plug is causing another issue that can create that scenario, then it is the wrong plug.

If anybody wants to argue this I can hand you over to NGK's own website that explains this.

 

[DAMIEN1307]

I can simplify this.

You want to run the plug that is just "hot" enough in heat range to effectively self clean under normal operation. Basically, the coldest plug that still operates without fouling. Self cleaning ability is the reason heat ranges exist. Too hot and you can get pre-ignition. Too cold and you will foul plugs.

You are correct in that heat range of the plug does NOT affect combustion temps or operating temps of the engine directly. If the plug is causing another issue that can create that scenario, then it is the wrong plug.

If anybody wants to argue this I can hand you over to NGK's own website that explains this.

That is about the best way I have seen this plug issue of cold vs hot ever explained in simplistic terms thus far...Thanks Rocket...lol.