did I bend my valve??

[damann33]

Hey all, I got my engine all together and when I was trying to torque the flyweel I used shoe lace and put it down the plug hole to prevent the engine from spinning. I torqued the flywheel to 30 pounds, I just hope that I didint bend my valves, the engine is also spinning nice still, I probably didint do damage but let me know what you think, thankss

 

[tubes380]

shoe lace???
probably not the best way of doing it

 

[tormentandglory]

50/50 chance. If the valves were open (exhaust stroke) they're most likely trashed. If they were shut (compression stroke) they'll be fine.

 

[Hans]

You would have lost engine compression if you bent a valve..does it still run?..next time put it in gear 3rd or 4th... and lock the rear wheel...

 

[Sidney]

Wouldn't it just be easier to estimate if 30 pounds could bend a valve?

 

[tubes380]

estimate, then what??? your estimate is wrong and you find out the hard way, on the redline when all goes wrong?

 

[Sidney]

its more likely that the engine is fine so i think just see if it has good compression before you start it.

 

[damann33]

well this mornin I pulled the head off and checked to see if the valves were sealing and all looks good, I want to fire up this engine today and see how she runs, just need to hook up the exhaust along with the carb and im good The engine is all new I have not tryed starting it up yet, I have just finished modding it and putting it all together I will let you guys know how the engine runs with all the mods done to it

 

[damann33]

oh yea at first I was trying to change the gears to lock the flywheel, but it still turned freely, I think I only went into second not 3rd or fourth

 

[themountain]

Wow ...after tinkering five month with this engine its finally alive...congratulation!! ..better late than never

 

[damann33]

lol yea looking for the right parts, waiting for them to come in, being ripped off a couple times, wronge parts and now its together and running like **** lmao. The bike picks up speed, dies, picks up speed, then dies it aint running smoothly at all. I am suspecting the carb, I will be replacing the 50 pilot and putting in a 40 pilot, and I ay drop the main from a 105 to 100. Its a 26mm oko. If that doesnt work ill check my rocker to stem clearance, make sure the carb boot aint leeking, and if all fails it gotta be the exhaust valve. I double checked to see if the exhaust valve was sealing and it wasnt completly, pushed down on the valve springs a couple times and it seemed to seal better, so I dont know foresure if the valve is bent. ill keep everything posted

 

[themountain]

Is it idleing fine?? did you checked your ignition?? Whats the plug look like??If you slammed your valve your engine would be gone already...so , has to be something different!

 

[tubes380]

sounds like the carby, do the jet change and it should fix it up, might need to go down a couple on the main though, i had the same problem getting mine dialed in but its worth it

 

[damann33]

heyy, the problem was the cdi. It is a good thing I bought a race cdi on ebay because the stock one let go. The engine is running perfect right now, and has tons of torque and speed. I still have to fool around with the carb to get the right jetting, all I changed was the pilot jet from 50 to 43. Today I will be riding the bike a little more and testing it out

 

[numroe]

Shoe lace. Interesting. Next time you need to stop your engine from turning, try 4th gear as mentioned, and then to lock the rear wheel, remove the rear brake disc, then put a strong metal rod thru the rear sprocket and across the swing arms with rag on each end so no scratching. Then the rear wheel wont turn! That's what I've done in the past on big bikes when I have no impact wrench or whatever proper tools and I need to apply 100nm on some nut. Hopefully on a chinese mini this method wont bend the swing arm bolt. Probably it will though.

It's real easy to bend a valve. I bent one after a cam swap. Visibly no bend or gap to be seen. With a WD40 "leak" test it looked okay. But it whistled when the engine turned over and yep it was bent.

But your engine runs. So your valves are probably ok. Probably.

Sounds like you need to search for tips on 4 stroke jetting. It's not that hard. The gains can be huge. Cactus wrote a good guide on this site somewhere. I wrote a step outline here once too - I think. The general concept involves using tallish gear selection and noting throttle position and "snapping reasonably quick to that position" to set the main (wide open), then the slow(1/3 open), then fine tune the needle (2/3 open), and maybe go over the whole sequence again to fine tune. Oh and fiddle with the screw, but on my OKO26 the screw (where close to right) only affected to about 1/8th open.

For what its worth (not much) I have an OKO26, and in 20C at sea level with moderate humidity, and very good intake filter breathing I use: Main=(K102 or K105), slow=K38, needle up 1 posn (rich).

Don't forget to try a nice new spark plug.

AND dont forget to use fresh fuel, check your float level, always drain the carb bowl after washing and/or before riding. Else you might waste some time chasing your tail.