whatever Bluntz, lets stay on topic because it looks like people have some different opinions on different things because we didnt learn the same way and didnt have the same teachers obviously but its alright like that.
Lets be gentleman and respect each others and share our knowledge and ideas about the topics. If we dont always agree, its alright, we can mention our opinion but we shall do it with respect.
Its a vintage yamaha forum, not a honda civic forum.

I took the time to do a video for you guys. It should be up in a few minutes, ill give you the link.

Let's play nice fellas.

One thing to remember on this bike is if you are NOT running an air filter, you are probably getting a better air flow than WITH an air filter. More air means that the mixture going into the motor is leaner than the stock setup - all other factors being equal.

Indeed you are right, running no exhaust reduce back pressure and leans it as well, but for some reasons the spark plugs are far from looking lean.

I am gonna steal the its a Yamaha Forum not a HOnda Civic forum for a T-Shirt. Seriously funny.

Send me one of these t-shirts and it'll be good ahah :p

This is how the Rm 250 spark plug looks like.
Pretty black and it still works.
This bike is jetted for winter so its running very rich. (thats what i want)
Ive got about 5 hours on this plug
This is actually the same spark plug with 3 different light settings.








There is the link for the video. Dont forget to select 1080P HD.

I start the 1990 Slingshot Rm 250 with this nasty spark plug and i try to start the yamaha with 2 different type of brand new spark plugs.



If you are not interested about the suzuki you can skip to 2:00 in the video, but i recommend you watch it all if you have a couple of minutes.

Some say 2 strokes aint reliable. It aint true when you own a suzuki

What comes around,goes around......

I never meant to agitate you like I obviously have...

Since you asked, I did not read about the case leak issue anywhere. I took that picture myself of a case half I have on a shelf in my garage that has the problem I described. What I did was share my real life experience and observations so that someone else might benefit.

This forum and others like it are great resources. There are many very experienced and knowledgeable people on forums that I have personally learned a great deal from and have a great deal of respect for.

One of my shortcomings is not having enough patience with people who, often with very good intentions, go way beyond expressing their opinions or advice to others and attempt to back up their claim with pseudo-science and a BS story.

To answer your first two questions: 1) the crankcase is pressurized with low pressure air and the leaks show up when soapy water is sprayed on the area. 2) It would not hold pressure with the side cover installed. The transmission is vented to the atmosphere.

Just for fun:

Not 100% sure about a cigar but I believe a cigarette burns at a temperature just below the ignition temperature of gasoline... red hot steel temperature is many hundred degrees above a cigarette and well above the ignition temperature of gasoline. BIG difference. (The temperature of a spark is even higher yet which is why sparks are so dangerous around flammable liquids. Don't confuse "temperature" with the "amount of heat released" ...two separate things...)

And if you could submerge a sparking spark plug in a bowl of gasoline it wouldn't ignite the liquid... but the fumes around the bowl would likely ignite... gasoline requires a stoichiometrically suitable mixture of air and gasoline for ignition... too rich or too lean and no ignition.

The carbon deposits I've cleaned out of pipes with a torch or by packing the pipe in hot coals are not sticky and gooey like you claim... they are rock hard deposits that turn to dust when heated to a high enough temperature. (Again, not read on the Internet but from my personal experience. )

I've spent more than enough time with this... I hope you stay and learn and become an experienced and valuable member of this forum... or you can continue to post BS and continue to do your best to detract from and undermine this forum... your choice.

I actually posted the NGK information so you could verify the correct plug and/or ask questions about using extended tips and hotter heat ranges or whatever else. They might even be able to diagnose a spark plug if you send it to them?

And unfortunately cleaning the deposits to restore a fouled plug often doesn't work...

To check your timing the first step would be to check the "workshop" section and look for the manual for your bike... That might not be too much help though but it's a place to start.

Basically, you want to make sure the points are opening when the piston is the right distance before top dead center... the two challenges are finding that point (easy with a dial indicator tool) and verifying exactly when the points open (again, easy with the right tool).

There might be a "timing tab" and mark on the flywheel that could be close to correct timing when they are aligned... and there are methods to determine when the points open without a factory tool... (ohm meter or even a very thin piece of paper or cellophane can be used to get close)

This was meant as a Joke DudeYou certainly thought it was funny when you said those very same words to me earlier in this thread though.
I am no expert or make any claim to be one.You will find that I have asked for as much if not more advice as I have given anyone.
I asked A question about your bleed down test because I have not ever done one.
I was not nor am I even now incited by your pompous response.You may take it however you like,if it upsets you so much that someone has a different opinion than yours we have doctors than can help you with that today.