Video at https://www.youtube.com/watch?v=W64-LJ7QwVE
It is a GY125 engine which is similar to our 167FMM.
Part 2 follows.
I don't think you need to remove the engine on the DF.
Printable View
Video at https://www.youtube.com/watch?v=W64-LJ7QwVE
It is a GY125 engine which is similar to our 167FMM.
Part 2 follows.
I don't think you need to remove the engine on the DF.
bow,
IMHO I wouldn't run the engine until you get someone to help you diagnose the problem. Might be a minor problem that could cause more damage.
Not running anymore, just wanted to record the sound to get an opinion on it. Thanks for the videos, I was hopeing there was not a type of timing chain in there. glad to see it is pretty easy to do. Gonna go through the videos a couple times before i catual dismantle to look. Just did an over view without sound.. hoping in there has something about torque specs once I figure out the issue, and hope it is minor, so i can put it back together. will keep everyone posted. And with pictures I hope. I may have my son set up the video camera and do soe filming so i can send it to you huys. You are all the best.
Quote:
Originally Posted by bowtiewagon
Another 2000 mile diagnosis, but its same as my first, that sound tells me you have a small leak in the head gasket, and if you say it stopped running was likely because when a small leak runs it quickly gets bigger until there is no compression.
Still, if it does run, dont run, because if im wrong as mentioned a small problem surely gets worse.
Take your time, watch the vid, no argument there, but you can pull the head off and diagnose this cuz its honestly plain easy to do what you need to.
I watched that video, good info and its very similar, but fwiw i don't think you need to take off the valve train as he does. nor do you need to pull out the rods as he does, but you do need to make sure that the rods sit right when you finally put it back together, no big deal. He mentions to be sure to put the rods back in the same place they came out, i dont have an argument with that, but they are the same part, i think since you should be checking, setting, running, then checking again the valve spacing, then it doesnt matter.
3 bolts to take off the head cover,
4 bolts to take off the head.
not much to it.
Finally proper assembly torque is important, i got 21 or 22 ft lbs from the honda cg 125, for lack of any specific info.
i do all the 6mm head cover bolts 6 or 7 lbs in aluminum.
ive taken and assembled this engine about 4 times for various reasons.
its really simple.
by the way a new gasket is less than 7$ on ebay, dont you dare pay more.
Why would you think it would have a cam chain?Quote:
Originally Posted by bowtiewagon
here is your engine
Mjh, just ignorance of not knowing the inner working thats all, no biggie. But thanks for the PDF .. helps out alot. Axa, Thanks also. In process of getting started to work on her. Weather looks questionable, so I am probably stuck inside the cramped space of the garage. But it is what it is. I will keep everyone posted. You guys are awesome. Thanks.
http://www.mychinamoto.com/forums/at...id=18421&stc=1http://www.mychinamoto.com/forums/at...id=18422&stc=1http://www.mychinamoto.com/forums/at...id=18423&stc=1http://www.mychinamoto.com/forums/at...id=18424&stc=1http://www.mychinamoto.com/forums/at...id=18425&stc=1
gasket looks good, but I am going to get another one anyway.. no rips tears, or anything, but still could be bad.
any one else have input?
No signs of a bad head gasket.I would replace it just to be safe.The sound in the video sounds like an exhaust leak between the header and head.I would replace that gasket as well.The intermittent running could be a coil,pick up,or CDI starting to fail.They all do wierd things when they start to go out.
also would this be tha same.. it says for a CG250, but it looks the same. http://www.ebay.com/itm/160293568896...%3AMEBIDX%3AIT
ben, I have been trying to find a new gasket for the exhaust but the three I purchased thinking they were it, were to small. have not had any luck with descritions and these sellers answering back.
whats a pickup? I know what the coil is, and maybe the CDI although I could be wrong. please advise.
Try to match it up at a dealer, and then see what online prices are going for on the same P/N.Quote:
Originally Posted by bowtiewagon
The gasket does not look that good to me but I am miles away.
Check your head for flatness https://www.youtube.com/watch?v=qCMZGaLSO8w You can use a piece of flat glass for the flat surface.
If you can get the rear wheel off the ground then put the bike in gear and turn the wheel and listen for noise.
http://www.scooterparts4less.com/web...ust_gasket.htm
Measure the exhaust port and select size from chart above.
this gasket is fine. i think i bought from the same guy some time ago.Quote:
Originally Posted by bowtiewagon
heres a cheaper one with bottom end gasket included
http://www.ebay.com/itm/191242927459...%3AMEBIDX%3AIT
I often use rolled up tin foil, but this is a decent deal.Quote:
Originally Posted by barnone
Quote:
Originally Posted by ben2go
I have to agree it doesn't 'appear' to be at all damaged. Mine looked like it was blown out about an inch in the circumference. i speculate i under tightened the the head bolts as i didnt take the time to get the specs.
But what I should have suggested is try to get a sense of where the leak was (by putting your hand around a pumping head) preferably before it stopped running for good.
now again supposing it is a head gasket leak cuz u stated power loss (and not a exhaust leak where you wouldn't lose much power just backfire alot) you must check for flatness.
If you cant find a warp, you will need to clean it up with acetone, seal it back in place, and see where the leak might still be, you might just get lucky and the problem gone.
(Its not beyond comprehension that your bolts just loosened up)
but be sure to let me know if you find either your mating surfaces, head or cylinder, warped.
But take your time to try and isolate if speculation has been utterly inaccurate thus far.
bow,
Too bad we didn't suggest a compression test before the head was removed.
I ordered the head gasket. Also the exhaust gasket. Problem I have with all this is that when it was running during the video I showed, I was getting smoke out the exhaust. I have never had smoke out the exhaust before this. Plus puffs out the intake filter as well when i shut it off. Thats is what lead me to believe it may have to do with the timing more than anything. once the gaskets arrive (botht of them. I will get it back together and hope we are good, and keep ya posted. Thanks again all.. very helpful.
bow,
Not so sure that you had a bad head gasket. From original post
"Was in the process of pulling out of a driveway from work, put her into first, large dathunk ,stalled, hard to restart, got her going and no power at all, stalled again, and would not start .."
I suggest you turn the engine over before you put the head back on and listen for noise.
Put the bike up on blocks so the back wheel is off the ground, put the bike in gear, and have someone rotate the back tire and listen for noise close to the engine.
Also check the head for flatness before you reinstall it.
yup a compression test would often be a prerequisite, but honestly i don't have the tool and never see myself getting one.Quote:
Originally Posted by bowtiewagon
but going off the "no power" part of the statement, i do think that much of a leak would be noticeable whether its a hole in the combustion chamber (gasket or otherwise), or worn piston rings causing blow by.
anyway, its easy to jump to conclusions; efficient diagnosis is really a methodical process.
ill be sorry if this all ends up to be a leaking exhaust gasket causing a big change in the combustion mix... but ive run with out a gasket and the worst of it is severe backfire, the accumulating smoke at stop lights was unsettling as well.
I've used my compression tester like this one below many times over the years. Should be done before tearing into an engine.
http://www.ebay.com/itm/Professional...-/321971101392
Maybe one can be borrowed from a auto parts store.
Really doubt this problem is caused by the leaking exhaust gasket.
The cause of the "loud dathunk " needs to be found.
I wonder if a valve adjuster backed off enough to not open the valve properly.
I am pretty sure the adjusters are tight. but once I get her back together I will triple check the gap.
If I could reach into this forum and give every one of you a firm hand shake I would. I want to thank each of you for the awesome assistance for helping me get my baby back on the road. Head gasket it was.. so it seems. It came in yesterday, I put her all back together today, and took her for a nice ride. She is practicaly new feeling. You are all the best. I have learned much from each of you, and hope we can all continue to support each other through our coming rides. Peace and respect and a hearty thanks.
im real glad for u. and just think, you guys were this close to picking out a new engine.Quote:
Originally Posted by bowtiewagon
did you torque to about 21 ft/lbs i think i read.
i bet it was your just your head bolts that got themselves loose over all those miles you rode.
bow,
Great news. May she run another 18k miles.
turns out I just broke all 4 rear sprocket kush bearing studs.
i already know others have complained about these likely having broke them.
I'd recommend taking the time to change them out before you run in to a problem. I've not even got 1800 miles or so.
many thing are life threatening on a bike, might as well eliminate the ones you can.
i just ran a failure analysis on my sprocket bolts and found all 4 had deep and smooth beach marks covering for a majority of the shear area, leaving a fast failure on a minority of the area.
This means that the process was long and slow, and only took a light load to break at the end (which was true as i was just pulling out of a stop)
I cant really tell if it was just the material being shit, or if it sat in the kush bearing hole too lose movement, or if the shoulder of the bolt was turned with a too sharp angle by a dull tool which allowed the tiny smooth cracking to begin.
But these all seem a problem, and a systemic one to Chinese manufacturing, imho everyone should swap these bolts out.
http://www.ebay.com/itm/NOS-OEM-GENU...NWuR93&vxp=mtr
Changed them out severals years ago when I changed the sprocket.
thanks for the link, those show the proper rounded shoulder instead of the 90° edge the stock came with.Quote:
Originally Posted by barnone
i found similar sets last nite, and i turned a new set this morning before work...
to a not for profit machinist like me, 24$ for a set of bolts seemed really outrageous
but then there are these, 2 sets for 9$, though you'll probably end up with the same problem later.