Tutorial: Setting Valve lash and Points Timing on honda trailbike. (ct90 and others)

Couple details:
1: A #2 Robinson wood screw (square head) bent on a 90 makes a valve wrench.
2: You may need to disconnect the ignition wire leading to the coil in order for you static timing light to operate correctly, in other words you need to isolate the points "switch"
3: Get a JIS screwdriver instead of a Philips like I named in the video, JIS screwdrivers are like Philips in shape but they are designed to fit properly not "cam out" which is what Philips is designed to do. JIS screwdrivers and bits will fit the fasteners on these bikes properly.
Full service manuals HERE: ct90-ct110.com/...
Thank you for joining me for this short tutorial on how to set the timing and valve lash for many common Honda horizontal engines and four stroke Chinese clones. These engines were sold on pretty much any small bike you can imagine, Chinese kids quads, kids bikes, the fabled Honda passport and many many others. This specific tutorial is for a 1972 Honda CT-90 but the principles in this video should apply to pretty much every one of these single cylinder horizontal engines with points.

[@MYCHANNELWITHMYSTUFF]

@ 3:55: You can use a multimeter set to continuity instead of a timing light if you don't have or don't want to make a timing light. The multimeter will stop beeping when the F mark passes the position mark.

[@megastick9324]

Can also use a 12v test light.

[@megastick9324]

FYI, pumping the throttle before starting does nothing, nothing at all. There is no accelerator pump on these carbs. It het no fuel from pumping. Also, after adjust points, use some very fine grit sand paper and drag across them, this gets any oil or grease off and cleans any carbon. It’ll start easier clean because it’s not searching for a good contact point. This is on anything with points. Good job.

[@tomsmith1390]

I was working and learning on these machines back in the 1960s-72 in Jack Tracey's Harley, Honda dealership and shop in Yonkers NY. I put a 1974 CT 90 back together some 5 or so years back, just to go back in time. You did an outstanding job with this tutorial and brought back memories archived in my mind for over half a century. Great job, Thank you.

[@Max_Marz]

Thank you man, very sweet comment. I’ve come a very long way in understanding these motors and technical abilities since I made this video even. Last year I rode an 86’ ct110 cross country and back

[@AlanHardacre]

A good investment for anyone working on old Japanese bikes is a set of JIS screwdrivers. All the Phillips-looking screws on a CT90 are actually JIS. You can tell by the little punch mark in the head of the screw. JIS, or Japanese Industry Standard screws are just different enough in shape that Phillips drivers will not fit well and slip/strip them. The difference is in the leading angle of the point of the driver. Phillips bits have a larger angle and therefore don't bottom out in the JIS screws, causing slippage.

[@Max_Marz]

Thanks for the comment, you are absolutely right. I made this video before I learned that detail! Vessel sells a very nice set of 3 bits that I have been using ever since.

[@ridetolive382]

Great video so glad I found this. I am working on my 72' Man, ballsy to do that with such a dirty bike hahaha I was waiting for an avalanche of mud to fall onto your valve... Thanks for the great info!

[@famillebussieres-mainville4831]

Thanks for putting up this video Max. Helped me figure out how to properly set the points on my k0 ct90. Finally got it started! Now to figure out why there's no more years after riding it for a half hour or so... Cheers from Montreal Canada!

[@AdventuresWithNimby]

Great video! A #2 Robison wood screws fits like a glove on that square set screw makes a quick cheap tool and easy to work around. Just put a bend it and some tape on the threads.

[@DbeeSapphire]

Thanks Max. I appreciate the easy to understand tutorial. I just finished making the timing light from a pocket flash light. Haven't tried it yet though, it's a bit late at night.

[@bradleyjohnson452]

Great video. Only 2 suggestions. 1 try to reposition so there is not a shadow and 2 clean the bike first so there is less chance of debris falling inside.

[@kelpcreeper]

Well done. You had good shots of what you were doing and everything was explained without any extra bs.

[@Max_Marz]

Thank you! I really appreciate the feedback.

[@edwardgolonka-jd4sc]

The dry pan 🥘 for parts is a nice touch if ur running late for lunch u can dry up some 🥓 while working lol

[@jraiello]

The proper order on most Honda’s is timing chain, valves, then points and timing. This is due to the former could affect the latter adjustments. Due to timing advance mechanisms, the best is to use a real timing light that attaches to the spark plug. Then you can ensure the timing is advancing as you increase rpm. If you follow this procedure, you will have everything perfectly adjusted.

[@opinion4246]

Thank you very much. U showed it clear👍

[@joecorrie1]

Great video thanks for posting

[@dutchman56t]

Nice job Sir! Made it look easy, as it is. Keep it up!

[@everettthoman2097]

I have a 73 st 90 starts but stalls put after a few mins then impossible to start after it stalls . But the next day starts right up and does the same what should I look at

[@jameseastwood4984]

Thanks for posting.

[@motomanmexico]

Thanks for the video, very helpfull, My CT90 will be happy here in Mexico.

[@bankayhoodlum]

It’s “right before” but exactly 5° BTDC according to the manual. Measure it.

[@The1scooter]

loved the video. one question with the timing part. shouldn't the light turn on promptly after the "F" mark?

[@Max_Marz]

I show how the timing should be correctly set at 6:33, as you say it should go off at the F mark.

[@benjaminsalopek3394]

The light turn on as soon as you hit the F mark if you’re on the compression stroke, not before or after. You will see the points just start to open as you approach F and at this time the light should turn ON

[@mytidawg]

Hi Max....great video.......hey I was wondering do you know what this sound might be in my gearbox??...i made a video ..... The particular noise only comes about when I'm accelerating....giving it gas......when coasting it seems quiet down and be totally absent. At first I thought it might be the chain hitting the guard........Well that was not it....so then I got my head way down to listen as I was riding....trying not to run into the parked cars or curbs......I found out the noise is coming from the gear box trans area......it sounds as if a nut is flying around in there I put the bike up on a stand and sent her through the gears......once it gets up to third and is going pretty good you can hear the noise.......I'm kinda bummed since I just got her out of hibernation and up and running.....with a new battery on the way as well.....now it looks like I have a major issue within the gear box...... So any insight as to what you think it may be....clutch adjustment....timing chain...etc....I would greatly appreciate it....here's the video below.. kzbin.info/www/bejne/gGOVkHp_hZZ0p7s Vince San Jose , CA

[@johnda5640]

Very well done. Thank you.

[@alex993cc1]

mate keep it up this was fucking good job.

[@fredkeil9529]

I'm trying to get a late 67 CT90 running, when I try to adjust timing my light is staying on when the points are open and going off when the points close. Why would this be?

[@jondoe954]

so if i open my engine on that side it only has a cam, i dont see a spot to clip the red cable, i dont see the ignition cable

[@MsNevadakid]

thanks "max" ,very helpful..

[@samanthayost8538]

Why does my timing light never turn off? Even when I move that metal piece?

[@scottp7587]

adjust your points first, then time it.

[@hotbeerjosh9019]

Cant you use a multimeter instead of a homemade timing light?

[@Max_Marz]

Yep.

[@hotbeerjosh9019]

@@Max_Marz Your vid helped me out today. I used multimeter on continuity, but got it going. Check out the short vid I made today. My timing and points were way out of whack, and 1 valve out of spec.

[@quocluu1326]

Hi. do 1969 honda s90 share the same engine as the 1968 honda CD90? thank

[@Mogman150]

I believe the s90 and CL90 are the same. May be some minor differences in the CD

[@jayhawk184]

What if I cant get my light to shut off if I unhook it all together lights off but when its hooked up the way you have it it never turns off

[@jayhawk184]

Had to turn the key off and disconnect the green wire coming from the timing plate with the points on it

[@kubooynykh8136]

You are like ChrisFix

[@johnvest4216]

Hey quick question, I'm trying to adjust this on a 1969 CT90 that doesn't seem to be running that smoothly and has a hard time starting. The light goes off at just the right point just past the F mark ... my question is when is the light supposed to come on (ie: when should the points close initially). Is it right there at the double index mark where it is at 6:41 in the video? Mine comes on well before that, actually right where the arrow is and I suspect that's the problem. I checked the point gap and it's where it's supposed to be.

[@Max_Marz]

John Vest If the light goes off at the right point the point at which the light comes on is completely dependent by the shape of the timing cam on the flywheel. its not something you can adjust. I'm sure you have a carb issue if its hard to start.

[@johnvest4216]

***** Thanks so much for the reply and for this great video too PS. Yeah I could see where the cam was controlling the opening and closing and that cam seems to be in really good shape. I agree about the carb, now that I have the timing and valves inspected/set up it's on to that.

[@Max_Marz]

Right on man, good luck. Feel free to ask away.

[@am55vids]

+Max Maruszewski the info on how you put that light together? I'd like to do something similar to set mine up.

[@Max_Marz]

It came out of an erector set, i cut one of the wires going to the light bulb and put alligators in, any battery flashlight bulb or led will work just fine, the points are acting like a light switch completing the circuit from the battery through the bulb. Super simple.

[@jasonveilleux9791]

Thank you!

[@CarlosBookerPhoto]

More trail 90 videos!

[@1982pantro]

my 1968 ct is slipp8ng a few gears PLEASEany help is greatly appreciated

[@scottgutierrez9867]

Slipping like the clutch isn't fully engaged or slipping out of gear?

[@1982pantro]

what number do i need on the feelers gauge, can you please help me?im about to do my timing on the morning. when you say two thousands of an inch,what number is it?thank yiu so very much and merry christmas from arizona

[@Max_Marz]

1982pantro .002"

[@1982pantro]

Max Maruszewski .thanks for your quick response,i have my feelers gauge with me this is the number that is written on it .002 .051 mm this is exactly how its engraved. is this the correct one?

[@Max_Marz]

Yes.

[@1982pantro]

Max Maruszewski . AWESOME,thanks again for the video dude, awesome job.

[@Max_Marz]

It's not critical, you don't want them too tight or too loose, just a light pressure on feeler strip.

[@scottp7587]

did anybody see him tighten the points plate screws ?

[@Max_Marz]

👻-It is a mystery-

[@edwardgolonka-jd4sc]

Thx ur techie, but a good first step would be to wash it

[@jakedavid8187]

great job telling the idiots...(myself) how to do this in the most easy way possible.. i need all the help i can get... im assuming i can use my multi meter as a timing light? on ohms... when it goes to zero that when your light would go out... let me know if that is wrong. thanks

[@Max_Marz]

jake david yup, continuity mode for beep is fine too

[@Max_Marz]

this is called static timing

[@jakedavid8187]

@@Max_Marz cool thanks. much more easy as that is what i have already. why do you want to lose continuity at the point of "F" wouldnt you want closed contacts on the points? or is the only point you dont have contact to ground therefore it sparks? i dont really have to know im just confused

[@Max_Marz]

The coil/condenser is charging when the points are closed and fire as soon as the points open.

[@alex993cc1]

my only gripe is the shadow

[@Max_Marz]

The shadow played a key role in the closeups of the timing light :P But yeah this was really early in the morning, was kinda hard to get the lighting proper. When my shop is clean I wanna get a shitload of T8 fixtures and do this sort of video inside.

[@buckmaster5552]

my only gripe is the point adjustment is not shown

[@Max_Marz]

Larry Trodden do you have any questions? you just rotate the plate the points are mounted on to adjust it. loosen, tap with a small hammer, tighten, re check.

[@scottp7587]

@@Max_Marz i think buckmaster is talking about the point gap setting.

[@benjaminsalopek3394]

you actually want the light to come ON as soon as you hit the F mark and continue for the entire stroke or rotation. Your video is confusing. The light should stay on after the F mark for a full rotation, as that is when the points start to open and they stay open. You may be on the wrong stroke. Plus the valves should be adjusted BEFORE the timing, not after.

[@Max_Marz]

Plug fires when points open not when they close…

[@Max_Marz]

Also this procedure called static timing should always be followed by doing it with the bike running and with the use of a timing light, this procedure only gets you to the point of having a running bike which you can then time with a light properly.

[@benjaminsalopek3394]

@@Max_Marz Exactly. I know