1:11

[@mozer30]

Just a quick note, if you go too advanced in ignition timing, it can cause detonation which will be catastrophic for the engine. Higher compression ratios, lean air/fuel mixture, poor squish clearance, and low octane fuel can also contribute to detonation, or “ping, knock” as it is also known.

[@UpAllNight91]

Yes sir! That is correct.

[@bunnyman6321]

What's detonation?

[@mozer30]

@@bunnyman6321 quote “Detonation is when the air : fuel mixture burns at an extremely fast rate due to chamber conditions resulting in multiple flame fronts. Detonation results in a sharp rise in cylinder pressure and temperature far in excess of normal combustion. Detonation can vary in intensity from light, moderate, to severe depending on several factors.” It gets one of its names from the specific frequency produced by detonation, which causes a “pinging” sound from the cylinder. Modern car engines are fitted with a “knock sensor” that detects the frequency of detonation. When this occurs the ecu will retard ignition timing back to safe levels.

[@bunnyman6321]

@mozer30 I didn't know that bout modern cars. Do modern motorcycles come with knock sensors?

[@mozer30]

@@bunnyman6321 I’m Not sure about modern motorcycles as I’ve lost touch with the new technology, but it wouldn’t surprise me if they did use knock sensors, purely on the basis of the variety of fuels available at the pump (octane rating). Different octane ratings require different ignition timings to achieve maximum efficiency. With a knock sensor the ecu can adjust for that….otherwise a manufacturer would have to state to use a specific octane fuel eg “super unleaded only”.

[@mosesjennings4690]

Man you are the best on Yamaha bikes thanks

[@UpAllNight91]

Thanks!

[@robbidi123]

Great explanation. TY!

[@UpAllNight91]

Your welcome. Thanks for watching!

[@michellatour150]

Not sure if it was already mentioned but the reason most strip out those 'Phillips' screws is that..they're not Phillips! Any such screw found on a Japanese motorcycle will be a J.I.S. type screw (Japanese Industrial Standard) and require the proper drive / hex bit to loosen and tighten them without any risk of damage.

[@UpAllNight91]

Well heck I learn something new every day. Gonna order some of them up!

[@Graplernapler]

Hey man, thank you so much for all these videos - you’ve been a huge help to me in my own garage. Hope you keep it up, let us know how we can support.

[@UpAllNight91]

Ahh thanks man. And thanks for watching. Yes I do plan to keep making these videos as ideas and jobs that could make a good video come around. Thanks again for watching!

[@GregDunn-p9k]

Man I really enjoy your videos! You explain everything soooo well. Thank you for sharing your knowledge. Keep it up 👍

[@UpAllNight91]

Thanks! I appreciate you coming along for the ride!

[@lawrencecampbell9885]

Awesome man thanks keep them videos flying out. Regards South Africa

[@UpAllNight91]

Thanks! Sure will!!!

[@smcsumo]

Very well explained!👏👏

[@UpAllNight91]

Thanks!

[@johndeborg6606]

Another informative video ,you doin a great job dude ,I enjoy your vids well done. You would be a great trade teacher at college ,your knowledge,predictability and expertise would make u spot on as one. Your style would keep students attentive and remain interested and easy to learn. Thanks for your knowledge ,regards Johnny australia....

[@UpAllNight91]

Thanks for the compliments and thanks for watching. These videos have been fun making and sharing. They have also done me well in my own work, pushing me to dig deeper and learn more. I also have gained knowledge from reading the comments of viewers here, tips and experiences they have shared. I'm thankful for all viewers. This may just be dirt bikes but its my life and to have a chance to share with the world has been a blessing. I'm learning along the way, from video editing to trying to keep the attention of the viewer. Thanks for commenting and watching, I truly appreciate it!

[@johndeborg6606]

@@UpAllNight91 thanks 4 sending your comment to me I wasn't expecting that! I enjoy very much the way you do your videos and your so good at it the way you work on your bikes. Thanks again , Johnny australia...

[@250race]

Watch my video on the yz125 advancing timing .010

[@kenitsanoutragecandia3939]

Amazing info!

[@UpAllNight91]

Thanks!

[@justinfodor4304]

@upallnight91 solid video thanks for all the tips! Question for you - do you know what the appropriate squish adjustment is for 05 yz250 running 91 octane pump gas? I’ve read .045 Also curious to know how this influences timing and main jet size. Thanks for the help, brother!

[@UpAllNight91]

Thanks! For 91 pump I would suggest a squish arpund 0.050". Any tighter than that and it will be too much without running some race fuel in the mix. Apex heads set their heads at 0.050" and a slightly lower compression to allow the use of pump gas. The timing set to stock usually does the best on the yz250, not matter what head profile is used. However the jetting usually likes to be a little leaner on the main jet as the squish becomes tighter. At 0.050" you will find it will like about one main jet size leaner.

[@justinfodor4304]

Sweet! Thanks so much! As a quicker fix, you think I can run VP or 110 octane to mitigate the pinging?

[@UpAllNight91]

For sure, 110 leaded race fuel will allow you to tune very far into the red zone with no worries

[@declanhaider515]

Can you do a list off all the tools you used in this video?

[@UpAllNight91]

Just to line the marks or to actually break out a dial indicator?

[@rockman49er]

I got a kx250 but same thing thanks

[@UpAllNight91]

Yes sir! Alot of the Kawis also gave you 3 marks, one for dead center and the other two for retard or advanced. Pretty cool.

[@barkeep25]

Another great vid man. You think that a slight advance in ignition timing would help keep you from bogging down out of a turn w/o having to fan the clutch? Like when your in the wrong gear.

[@UpAllNight91]

Thanks. For sure it does help, especially on a 125. But its also always a trade off up top so keep that in mind

[@bubalachuulu267]

Hi. I have a 2011 yz125. Sweet sweet machine. I do all my bike maintenence myself as I am mechanically inclined. These videos are so clear and pragmatic. Beautiful. I do have a quick question though.... On the stock silencers there a ring in the end of it kind of like a washer making the exit diameter of the pipe smaller. What's the use of it? Would the bike be a smidge louder if it was ground out? Thanks

[@UpAllNight91]

Hello. Thanks! The ring on the end of the silencer are what they call a back pressure ring. The back pressure ring is used to tune in the pipes back pressure under heavy throttle. More back pressure does make more potential power on a 2 stroke but it can also increase combustion temperature and octane requirements. Pro circuit on a shorty silencer has a 24mm back pressure ring. On a 125 I have seen them range from like 22mm to 27mm. 22mm will make the most power but will also increase the temperature in the combustion chamber and require higher octane. The magic is finding the perfect balance between power output and not being too hard on the motor or requiring tons of octane. Racers with connections to a exhaust company are often given silencers with various sizes of back pressure rings to test and tune to the conditions and rider.

[@DariusBarazandeh]

Great video...where is the video on the YZ 250 timing? Was there another one? It sounded like you mentioned there was another one? Also does the YZ 250X come with a retarded timing?

[@UpAllNight91]

Hello. Thanks! I am not sure on the 250x, but I would surely remove the stator cover and check it. The other video mentioned in this video is this link... kzbin.info/www/bejne/oGO3c4KGbp6ej80

[@SSRacing66]

Nice job, did you ride the RCSX at Daytona a few days ago?

[@UpAllNight91]

Thanks. No I didn't. I probably should have. I did go though and while replaced a friend's clutch who was racing. Ran into friend's and even ones i haven't seen in years. Was a great time!

[@Blake_Guajardo]

Bro if I had a dollar for every time you said dial indicator lol

[@UpAllNight91]

LoL :)

[@derweibhai]

I have a 23 YZ125 that I am converting to an X model and using as a trials/enduro bike. I run 12/52 Sprockets, apex xc head, and the Berad freight train kit ( Lectron, reeds, head and funnelweb. I plan on changing the power valve when I do the next piston. I don't use any top end and would like the best off idle to midrange possible. Any ideas on timing for this application?

[@UpAllNight91]

Hmm. I would think cracking the ignition a hair advanced over the would be where I start. If your fuel is good it should be able to handle advancing a fair amount

[@braydendupre9059]

Need some help please I have a 2000 yz 125 and just changed the top end it backfires and won’t start is the timing off?

[@UpAllNight91]

Did you remove the stator or change it while doing the top end? How does the compression feel on the kick start lever, feel good? Start with a new plug, Make sure the piston was put in facing the correct direction. Check that the reeds are not chipping away. I would check them things first.

[@braydendupre9059]

@@UpAllNight91 I have the stator and I have compression new spark I’m getting spark and the piston was the right way everything it needs to start is good I cleaned the carb and jetting like 3 times so my guess is just the timing

[@bunnyman6321]

​@@braydendupre9059You figure it out yet?

[@braydendupre9059]

@@bunnyman6321 I ordered a ignition timing kit

[@bunnyman6321]

@@braydendupre9059 It solved the problem?

[@jojokarli]

Hello I’ve taken my shock high low speed adjuster cap off and it hasn’t got a washer it’s an 05 yz125 should it have one ? If so do you have a part number here in the uk its hard to find anything all I can find is the whole RCU SHOCK COMPRESSION ADJUSTER

[@UpAllNight91]

Oh man I honestly can't remember if the 2005 had that washer or not. Hmm, wish I had one here that I could open up and view. Don't think yamaha sells just that washer but I will check around a little and see if I can locate one.

[@UpAllNight91]

Technicaltouchusa.com sells the whole compression adjustment assembly but right now thier page seems to be down

[@jojokarli]

Thanks mate I’ve looked everywhere I can’t find that washer only the whole thing and can’t seem to find the parts manual for just the adjuster either but if you find anything please let me know much appreciated 🤙🏻

[@UpAllNight91]

@@jojokarli sure thing. But honestly if that washer is missing it will still work ok. So I would let that allow me to miss a weekend lol. Maybe just assemble it and keep on researching till we know. Did it come with one and if it did where can one be bought

[@jojokarli]

Yh I might just put it back together without it because I can not find nothing that tells me if the 05 has a washer or not. While I’m here how much nitrogen should I put back in thanks for all your help mate 🤙🏻