Part 18: 4 stroke how to set timing and determine TDC. YZ250F example
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- čas přidán 2. 06. 2010
- Part 18 of a series on building a motocross bike. How to set timing and determine TDC. Please subscribe and thanks for watching!
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Im 13 and rebuilding that same bike. I had it given to me. Your videos are helping me out big time. Keep up the good work man
Now your 22.....
@@cordbreon5417 😳
@@cordbreon5417 that hits hard ngl
Thanks! I'm glad I finally found your video!
great videos thank you so much for doing these
@Johnnysshop yh ok but do i need to set the pistion at the top of the cylinder sleeve b4 i put the magneto back on so i know were TDC is? not to sure :(
i am about to do the top end on my 2004 yz 250 f, i have never done motor work and was wondering if i have to remove the stator cover, and stator ?
well would this work the same way for a sohc 400 ex i think i have it almost right but it still wont fire any advice
my yz250f had a timing chain ratting noise. didnt think much of it cuz im new to 4t's. i kept riding it and then the next morning i was riding my bike and it wasnt pulling when i hit the gas it would go but if i put it into 2nd 3rd 4rth or 5th gear the speed and power stayed the same then it cutt off on me. now it will start for a second or to and shut off. i checked the timing tensioner and it seems fine. could it be the chain???
aligning the timing cam chains is pretty easy on most bikes. Find tdc start from the exhaust cam aligned then the intake. Keep in mind to keep tension on the side that has no tensioner. Then after the cams are aligned, release the tensioner and double check all your marks. Last test is to tighten cam caps and rotate the engine a few times and make sure your marks are aligned.
Do you have to be on the compression stroke to set cams? Or will it work out either way
I don't have that much experience in timing bikes but if I carefully followed this do you think I would have any possible problems? Cause my mechanic said that I couldn't do it
i haVE a 250 kxf it is glowing red how would i adjust the air fuel mix anyhelp would appreciate
2000 426yzf i put hot cams and auto cam in it ..but now i am trying too time it after topend rebuild and having trouble setting cams tdc ....the cam lobs are not the same so i think the book says too go with the middle onelevel,with punch marks and leavel with head ??chain loose 4th stroke ?? i know anuff too set tdc and put my cams leavel with motor but not sure ...nice videos
thanks for posting this video it comes in handy but im still stuck with one little problem.
basically i wanna know were to set the crank shaft cog before putting magneto back on.
i know how to do outlet and inlet cogs thanks to you jus stuck on that one thing can u help me please?
I have a 08 kx250f, I can't find any mark on my flywheel, also my timing chain had no where near the slack of yours even with the tensioner out makin it hard to put the cams in, when I do get them in the bike with kick half way an then lock
this glow is almost instant at start up it starts on the 3rd crank no smoke no oil in the water i will check to see if it glos while riding and get back at ya thanks for info water circulates to
@Johnnysshop Hey when I try to get my cams back in the chain is really tight any idea whats up?
The tensioner is still pushing on the chain
gracias por tu tiempo god
Hi johnnyshop can you please tell md if you can find out the correct year it is (Age of) as I want to change my clutch and am not sure the correct year,I don't want to purchase the wrong 1
when the tensioner is off, the exhaust and intake cams are perfect, but once i put the tensioner on the intake cam is a little off. the dot on the right side is a little low and the left side is a little high.
hey Johnny im having a problem reinstalling my timing chain its way to tight. it seems when you took of the caps it fit. what are the caps you took of?
Do you have the chain tensioner in?
hey , i don't have the dots to time my camshafts what should i do , there is to facing E in each cam
E's face to the left
@Johnnysshop yeah, you're telling me, im going to have to keep messing with it till i get it. lol this has been the longest rebuild for me they say 1st time is the hardest. earlier i droped a washer down in the cam chain area and had to take it app apart to get to it ):
Send me whapp number please
I cannot get one of the timing chain guides to come out. The guide on the exhaust side is stuck. Any ideas how to remove it?
Jesse The Baldy Ventura the guide on the exhaust can’t be taken out if only the valve cover was removed, the head needs to come off to remove the chain guide
i have a 2000 yz426f and im reusing the factory cams.... when i got the bike the crank was destroyed so full tear down. i dont know how to time my cams... the E and I marks i see on here so much dont exist on these cams its just dots in 90°s. HELP!!!!! lol
+Buubas Welding Here's a pic I found on the web that should help
nichelob.smugmug.com/photos/447916183_a68c2-L.jpg
the H I is the refrence to tdc right? one thing is for sure, i really want to complain to yamaha, because the markings on my flywheel ( H I ) is barely there, you have to look really close to see them, and thats annoying ...
Thanks so much for your yz250f videos. I am working on my 2004, and trying to reinstall the cam chain on the cams. The motor is in the bike. The chain is too tight to get over both cams. The chain tensioner has been removed. Any advice?
Make sure the cams are fully seated.
You will have to pull one can over towards the other and over lap the teeth pull chain over then will cam into its spot just did it last week same bike
@Johnnysshop turns out i was putting the tensioner on totally wrong. latter on i found out that it has to be fully compressed then put on. this was the timing didn't move at all.
hello,
at how many hours do i need to change my piston etc on a Yamaha yz250F from 2013, i am a strarting rider
Really depends on how you ride it. I would check the valve clearance every 12 hours of so, you may not need a new piston for 100 hours if looked after.
I have a 05 yz450f I believe I have a timing problem, when I went to check tdc I realized the person I purchased the bike off of has put a aftermarket cover case on that does not have a viewing glass to make sure my lines line up off the magneto. What to do?
dane conway thatsight glass is for oil level there should be two plastic caps with slots for flathead screwdriver on the left side of the bike those are for timing
អគុណបង🇰🇭
yes i do
With piston #1 at tdc, what should be the state of intake and exhaust valves for cylinder 1 for the engine to be synched? An answer to this will help me a great deal bse I have failed to learn how to time 4 stroke engines for that reason.
This is a single cylinder motor.
Now is that TDC on the compression stroke. or the exhaust stroke. I had to do a complete rebuild and I cant figure out how to get the crank at TDC on the compression stroke, so I can set the cams "o" to be lined up with the case and the other"o" with the chain.....
Same bike as in my vid?
i did a compression check had good compression did the valves now have no compression what could it be
Bye bye valves
I wanna go buy this 2002 yz450f, it's up for 1500. says it needs the timing adjusted. I think I'ma be able to do that just fine but he said it doesn't run because the timing was so bad. is there any way to be able to tell if it's timing by kicking it over? or if there are any other issues? do you think this bike will be worth it? I feel like even if it is not fixable for a reasonable amount fo money I could part it out and make maybe even more than I paid for it.
the bike looks decent itself the number plates on the sides r kinda crappy but plastics are cheap
Did you end up getting the bike and was it an easy fix?
@@andrewpergasorus3064 no dude sucks I wish I did
dial your exhaust valve to closing faster before inlet valve opening on overlapping position with drilling and moving (around 1mm depending on the dial result) those bolt that hold timing gear on the exhaust cam will make the power going up and giving you more acceleration, but to avoid overheating you must lowering the compression to 11:1 or 12bar.. you can try it, just buy new timing gear on exhaust.
Great info!
Hi can I replace timing chain witout taking the cylinder out?wr250f
It would be pretty hard because of the chain guide.
Thx
Boba
What is the thing on the left came sprocket??? My bike doesn't have one!? But it's a 5 valve engine idk if that means anything lol I just want to set the timing got it but I noticed I don't have a thing on my exhaust sprocket..
+Damian Lamb It's the auto decompression. Not all of them have it. What year?
+Johnnysshop it's an 04.
+Damian Lamb Pretty sure it should have it as well. You may have an aftermarket cam.
+Johnnysshop would that cause it not to run?
+Damian Lamb It would still run but may be difficult to start.
If by top end you just mean the piston, no you dont.
But, if your replacing the piston, I would highly recommend replacing the cam chain as well, which would require removing the stator cover/stator and flywheel. To remove the flywheel, you will need a flywheel puller. About 15$ on eBay.
Try setting timing when intake cam spun.cant use dots on sprockets.
Do you have to remove the cam tower?
Cole Braun Yes
Okay
My bike is a 99 yz400 do I set the marks to the same positions?
Cole Braun It should be similar
I followed this exactly and all it does is back fire it won't run start or anything except backfire any ideas?
Could be a carb issue as well but the "back fire" makes it sound like the timing could be off. I would double check to make sure all the marks line up on the crank and cams. It's pretty easy to be off by a tooth.
chad kangas i know its late but the flywheel spins 2 rotations for every one cam rotation so u have to make sure the I on the flywheel is alligned on the up stroke not the down stroke. I just did the SAME thing and had the same issue.
Putting the chain on the cams is a pain sometime it rotates and is a pain ..
my 2006 Kx 250f runs great if I bump start it. it's a bitch to kick. sometimes it will kick when warm. could this be the problem? can this be done with motor in bike? thanks, new to four strokes
Could be but I would look at the carb first.
+Johnnysshop
carb is good. one intake valve was .001" clearance. re shimming tomorrow. hopefully that does the trick. thanks
Good luck, hope that does the trick!
Why do cars use a pulley? Wouldn't minor slippage kill efficiency or even the motor?
Yeah but it's minor.
Cars? You are thinking of the timing belt on cars that is outside the timing cover. None of those pulleys need pinpoint timing. All you are doing is turning pulleys that need to turn for different pumps to work (for example the compressor, steering pump, fan etc. There is a timing CHAIN inside the timing cover that does the same thing as the timing chain here and keeps it all in time where there is no slippage.
viet nam :-)
i did this and then when i put the tentioner back on my cams were off by 1 link, but when the tentioner is off it looks dead on.. lol
that does not llooked timed right the exhaust cams one tooth to the left
A actual photo of the I would have been cool. This is first time setting and without actually being able see that mark kind of worthless. You couldn’t just point TDC mark out before putting cover on?
***** Hi,and on a two stroke how you set the timing ?
robin hood 2 strokes have no such thing.
ok thanks,that means a lot to me.
+robin hood theres no valves in a 2 stroke lol
+branden paquette there are valves on two stroke engines. Reed valves and power valves
To adjust the timing, please insert pink band and that advances the timing.
It would help if your fingers were not in the way
@nickiz1 next time ruby red fingernail polish haaaaaaaaaaaahaaaaaaa