ofna lx ultra one force .28 Large problem
 

hey guys i am new to the forums and had nowhere else to go
i have had this car for about 2-3 years and have put maybe 2-3 gallons through it. i am planning on using it more often now. so tonight i went out and ran a tank through it in the 20 degree weather, tuned rich for the weather and was working flawlessly so when i was done i cleaned it and put after run oil in the jug through the glow plug hole. i then notice i put to much in and try and dump the access into the sink, then put the glow plug in and spin the engine over with my fingers via the bottom of the buggy, it felt like there was resistance but not like i could not move it it was kind of bouncy, i notice i can barely move it like it has extreme compression i use both of my thumbs and it spins over so i take it outside and spin it over with my roto start with the plug out upside down then go inside and put the plug in and spin it with the roto start and hear a loud metallic knock so i take the plug out and spin it upside down again and put it back and it still knocks i may have seen a metal shavings then i immediately stopped and came here. i will tear it apart and see if there is anything wrong help is greatly appreciated.

Broken rod?

"Hydro lock"
 

It sounds like you hydro locked the engine even though you thought you had pumped all the oil out of the engine the crank case can hold alot of oil and when you turn it back over and put the plug in it, it was just the right amount of pressure to push the rest of the oil from the crank case and I hate to say it but that 28 you're running had a really soft piston and a really hard wrist pin and more than likely you ovaled the slot in the piston where the wrist rides. or it could have happened on the other end at the crank and the piston rod.

Lets see- spin start,pull cord, or bump box. Maybe, just just maybe, the one way bearing is going ga-ga. If not go ahead and play taps over it and start shopping. Good luck.

thanks for the fast replies i took the engine off and tore apart the Roto start assembly and the backing plate assembly and looked into the engine all looked in order the rod was there the little pin for the starter and i have replaced the one way bearing not too long ago. and the crank case was not full of oil at all so i did not hydro lock it it was all evenly coated in oil with a coating of oil over the bottom where the wrist pin rides. what i think it may be is the glow plug hitting the top of the piston i believe i am running the correct plug though i will look it up i am running a mc-8 mcoy

ok.....so i just put in my glow plug and put the piston top dead center and move the engine back and forth in quick secession in small movements and noticed my wrist pin that connects the connecting rod to my crankshaft has about .2 mm of play in and out is there something that holds that in ? i mean it goes in and out horizontally .2mm

Keep in mind, if you do blow up your engine (I've blown 2 con rods in my Force .26's in my LX Comp) you can send your mangled engine back to Ofna (call them first) and they'll send you a rebuilt one for $80. Not a bad deal. The force engines get a bum-wrap, but honestly, my Force 26's were great to me, and were easy to tune, just didn't like being at high-RPM too long. SNAP!!! :ha:

haha yea i dont think i need a new one but if you could email me that info it would be great [email protected] or do i just call them ?. anyways i think the connecting rod being so lose may be the problem but i need to know if i am missing something ? because i replaced the backing plate myself and had no directions so is there a fastener that holds the connecting rod to the crankshaft ? or does it just slip on ? i mean i put a spring in and then the little shaft for the starter and that's it right ?

could it possibly be my connecting rod crank bearing ?

Actually $80.00 gets you a new engine not a rebuild , you send in a money order for the amount of $80.00and your old engine, your name and return address(no P.O. boxes) just take off your engine mounts,clutch,flywheel and air filter and send it in for a new replacement.