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Post by dollartwentyfive on Jun 20, 2020 10:19:34 GMT -5
Thanks! I checked it out and the rubber o-ring had come apart. It was half out of the hole. I replaced the choke w/a new one and took it for a ride, same problem. Nature of the issue was exactly the same. Back to the drawing board😥 the problem will not be solved by replacing the choke with a 12v model unless the OEM choke is a 12v model.
apparently you do not understand the issue with the honda 244cc. the issue is the 244cc has a choke that runs directly off the alternator. the alternator produces an AC voltage well in excess of 12DC, somewhere in the neighborhood of 70v. replacing this choke with a 12v model will result in an IMMEDIATE burnout.
i replaced my choke 3 times before i realized this.
i finally came up with a workable solution. i had to tear apart one of the old chokes to see how it worked, then i used a second one to fashion the replacement. i didn't have starting problems until the temp fell into the low 50s, but a simple hand over the intake for a moment while starting worked. my intake was an airbox that rested on top of the CVT. i didn't have to dismount to choke it.
anyway, good luck.
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Post by dollartwentyfive on Jun 19, 2020 22:15:09 GMT -5
another name for the valve is the air cutoff valve. (check number 6 below) here's a good resource for you, some good stuff at this site:
engine service manuals: |
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Post by dollartwentyfive on Jun 19, 2020 15:20:29 GMT -5
the only way i know of to check for correct cam timing is through the plug hole on the right side of the engine.
this is VERY HARD to do with one person because you need to verify if there actually is a mark.
i can't imagine a cam manufacturer not marking their cams.
i never had to deal with this on my engine so i'm not too sure of the procedures.
i highly suspect that choke though.
replacing it will do no good unless you get it from a honda dealer, and honda dealers don't want to sell parts for non honda products.
almost all of the problems i had with my ride was electrical.
the choke was one of them.
an intermittent short was another, it wasn't enough to blow fuses but was enough to prevent WOT.
it took me 6 months to whip that beast into shape, but once there she stayed there until she died.
and i rode it HARD.
about 4 years ago i had it cranked out on a country road and the engine let go with what reminded me of the starter clutch engaging.
it ground to a stop within 2 seconds and hasn't started since.
RIP buddy, yeah she was my friend.
okay, enough of that.
you can find some excellent service manuals online for this engine.
look for a cn250 honda helix service manual.
it's too bad i can't upload them to you.
good luck
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Post by dollartwentyfive on Jun 19, 2020 9:32:59 GMT -5
Yes, I feel I am throwing a lot of repairs at this issue too! But thankfully its not my main bike so I can take some time w/it. Does the air bypass valve have another name? I googled it for my cvk carb but couldn’t find anything in the diagrams, and everything is connected properly. The choke seems to be working perfectly. Its a genuine Honda unit & the system is 12volt. It pulls off after about 3-5 min. Getting back to the timing, its an after-market cam (endigo rock crawler) & I’ve read that these could be off by a couple teeth & the motor will start and run fine, except for higher rpms. I have a timing light gun, can this be checked? Thanks for any insights. i'm not sure if the valve has another name. i also believe the OEM carb is 172mm.
the timing issue can be addressed by removing the plug, use a coat hanger to determine TDC, then notching the crank. you can then use a strobe. plus, there is a plug on the right side of the engine that can be removed and you can view a mark to determine if the cam has been timed properly. this process is very difficult to do visually without a strobe.
be aware that the 244 uses what it called a "wasted spark" ignition timing, the plug fires both at the end of the exhaust stroke and again at the end of compression.
also, DO NOT use the running method to set the valve gap. honda specs calls for this gap to be set with the valves cold and the engine not running.
replace the plug with an iridium plug, pricey but well worth it. this alone solved a number of my idling problems.
once you get all the bugs out of this 244 you'll find it to be a fantastic ride. mine could easily do 70mph and got between 52-55mpg. i used 20gram rollers.
also, do not use "thread lockers" or "gasket sealers" on your 244. remember, these engines are ALUMINUM and are easily damaged by the use of such compounds. use only fluids safe for aluminum engines.
questions: did you buy the bike new or used? does your bike have 1 or 2 radiators? are you SURE the choke is 12 volt? the bike might be 12v but the choke doesn't run off the 12v system, it runs off the alternator.
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Post by dollartwentyfive on Jun 18, 2020 20:05:59 GMT -5
I have an aftermarket carb, so I don’t think I have a bypass valve. that's what air bypass valves are for, to prevent backfires on deceleration. i believe you are throwing a lot of unneeded repairs at this problem.
another thing you should be aware of with the cfmoto 244. the "choke" is run off the alternater. if you have purchased a 12v model of this choke, it won't last long. i've burned out 3 of them before i discovered this. i found a workaround but it wasn't easy to fabricate. the problem is you simply can't remove it or unplug it, you have to disable it in the "off" position. if your ride doesn't perform well, then this can be your problem. but the backfires are caused by the missing air bypass valve. i've put over 10,000 miles on my 244 so i know my way around them.
good luck.
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Post by dollartwentyfive on Jun 18, 2020 9:24:42 GMT -5
ok, like i said, it's the air bypassvalve, and it is operated by manifold vacuum.
i've eliminated the vacuum operated gas valve, replacing it with a manual shutoff.
my manifold vacuum connects directly to the air bypass valve and nothing else.
there are 2 ports on the valve. one on top that points backward, this connects to the manifold
the other one points to the left and connects to a port on the left side of the carb.
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Post by dollartwentyfive on Jun 18, 2020 9:10:18 GMT -5
Hello, I’m getting popping/backfiring/lose of power when I back-off wide-open-throttle. I have a rock crawler cam, which I’ve read could be off even when installed correctly. Can the timing be checked w/a timing gun? I’d hate to try the ‘reinstall a tooth off’ method til it works. What’s strange is that this problem occurs when hot. Its fine when warm/cold. And wot is mostly good. Could this indicate a fuel mix problem? (Jets, vac leak, etc) I’ve went up & down in main jet size but the nature of the problem remains exactly same. (#145 main/ 40 idle) I know its hard (Impossible!)to diagnose over the net, but I’m just looking for suggestions. It has a 32mm carb, k&n air filter, & stainless exhaust.(stock cdi) Plug reading looks textbook (medium-dark gray) Gasoline is fresh, gas filter is new. Could a petcock be restricting fuel flow? Wouldn’t that happen at wot also? Can this be checked? this is a carburetor problem. air bypass valve to be exact. the hose has come loose, has rotted, or the diaphragm has rotted. i'll have to take a look at mine to give specifics.
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Post by dollartwentyfive on Mar 16, 2018 11:41:14 GMT -5
i don't know if it's been mentioned, but an electrical short can cause you throttle problems.
i had all kinds of problems with the enrichener, and it was because of electrical, not the carb.
a frayed wire on my ride was scraping on the frame.
it wasn't enough to blow any fuses but it was causing me acceleration problems.
and of course, the standard carb service.
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Post by dollartwentyfive on Jan 22, 2018 10:54:33 GMT -5
2017 taotao lancer 150, whenever the temp dips below freezing the throttle locks, works again above freezing. Took it off lubricated well to no avail, ordered new one, any ideas  yes, replace the cable. the wire inside theses cables is made of a bundle of finer wires. these fine wires will rust and break over time and will eventually "ball up" inside the sheath. throttle cables should be adjusted for about a quarter inch play on the throttle grip. |
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Post by dollartwentyfive on Oct 12, 2017 9:56:41 GMT -5
i don't see how a malfunctioning SE valve would prevent your scoot from starting.
they either have fail open or closed.
if they fail open, this is the normal position for starting.
if they fail closed, then choking the intake will start the scoot.
the only other possibility would be a shorted turn, and this would cause an excessive current drain on the system.
i doubt if this would be enough to cause a no start, but it seems it would prevent WOT.
SE valves can definitely cause idling and running problems though.
i found a way to disable mine, and i had no problems starting my ride down to about 50 or so degrees.
i didn't ride in colder temps.
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Post by dollartwentyfive on Oct 10, 2017 7:55:42 GMT -5
the ignition system on these scoots are pretty simple.
you have a pulse pickup located inside the engine with the stator.
the CDI.
the coil.
the plug.
that's it.
there are some safegaurds, like a sidestand cutoff switch, but these can be simply unplugged to bypass them.
if all of the items you replaced actually work, then the only options you overlooked are the cutoff switches and the pulse pickup.
also, seeing as the scoot sat for 6 months, personally i would squirt some mobile1 into the cylinder (not much) and turn the engine over a few times before i fired it up.
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Post by dollartwentyfive on Sept 27, 2017 14:57:15 GMT -5
jasper,
50 to 100 volts of input to the coil seems excessive to me, and quite likely has burned out the coil.
i would imagine that the CDI isn't really a capacitive discharge but instead relies on the coil to give the voltage increase.
this would imply the CDI output be a maximum of battery voltage.
i have no idea how you measured these voltage spikes with a multimeter, they are of such short duration that only an oscilloscope can detect them.
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Post by dollartwentyfive on Sept 27, 2017 1:24:21 GMT -5
It came up a while back it is a relay, I think JR settled this the last time. John Id say its a high/low beam realy... Hot, switched ground, and two outputs, would make electrical sense if using high watt dc bulbs. along these same lines, it could also be a modulator, switching between high and low beam. my scoots (i had 2) didn't have high or low beam headlights. in either case, it wouldn't hurt anything to bypass it, but a modulated headlight will make you more conspicuous. |
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Post by dollartwentyfive on Sept 25, 2017 12:47:48 GMT -5
kat,
when storing your bike for long periods then periodically starting it, be sure to allow it to run for at least 15 to 20 minutes.
this will drive off any condensation in the crankcase.
condensation is the number 1 cause of sludge in the oil.
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Post by dollartwentyfive on Sept 25, 2017 4:27:59 GMT -5
engines with pushrods are good engines, but they can't handle rpms much higher than about 8000.
i would imagine that most shop repairs are caused by the rider over taxing the engine. (other than warranty service)
this probably explains why most chinese engines just don't simply blow up.
they are better equipped to deal with high rmps AND most have rev limiters.
a 250cc is the minimum stock scooter i would take on the interstate.
i only rode mine short distances on state roads approximately 20 miles or so, some longer some shorter.
the majority of my miles was on county roads.
i would be hesitant to take a small wheeled scooter on the interstate.
i've hit bumps in my car that would probably wreck a bike.
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