has this happend to you

M

minibiker

Guest
my brother and i went riding yesterday (he has a dax 70/80 hes not into the forum hed rather me do all the work for him) but we were cruising at about 30 and i look back to see him staring at something i turned around and when i got there i realized his engine fell out!!! the head of the mount bolt that went thru the frame sheared clean off. it was bent at about a 45 degree angle, the chain was bent and stuck behind the drive sprocket i had to pull the sprocket off the case. the hard part was getting the rest of the mount bolt out becuz it was just the head that came off i coulnt pull the engine up cuz it didnt have enough clearence so a had to cut it with a dremel and it came out. but i was just wondering if any one else has had that problem
 


spunout

Member
Joined
Apr 24, 2007
Messages
769
no, minibiker. i can probably speak for the rest of the entire world, when i say thats never happened to anyone else. ever.
perhaps nothing was tight. its very important to make sure your nuts, bolts, and screws are tight. a pre-ride inspection may have taken care of that.
did the motor survive?
 
D

DougC

Guest
I don't have a Chinese kit--but for my GEBE custom setup, I have an infatuation with nylock nuts.

It's gotten to the point that I will only buy regular non-locking nuts when I know that a nylock nut won't fit or otherwise work (such as, loads on both sides of the nut)....
~
 
J

japat100

Guest
vibration is a killer ,,

if there is any one thing that would help improve these motors is proper motor mounts ,,, set in rubber ,, vibration is a killer ,it destroys everything ,yes even light bulbs and switches .. it seems that everyone including myself keeps giving advice on how to keep your nuts tight ,, lock nuts ,lock tight ,better bolts etc. about 90 percent of all our problems is caused by vibration and yet very little discussion on motor mounts set in rubber ,, we live with vibration and somehow we think its the norm ..and i don"t see anything or any co. making even a try at improving mounts for 2 cycle kits ,, theres got to be something better .
vibration should be the no.1 topic on this forum until we find a answer ,or get some co. to make proper mounts ,and i would not be surprise that a motor set in rubber may get 20,000 or 30 ,000 miles before it burns out no matter what kind of oil you use ,, power saws 30 years ago wide open ,used every day would last 5 years ,i would say that is equal to 200,000 miles ,if not more , and they used any 2 cycle oil ,, so why so much discussion about oils when we should be talking about vibration ,,

not only will your motor fall off ,, a neighbor took my bike for a ride and he had to go back walking to find his faults teeth ,, yes the vibration through his faults teeth right out of his head ,,i suggested to him the next time he takes the bike for a ride he best use lock tight the red tube , on his teeth ,, he did not think it was funny ,, o well no sense of humor


japat
 

bamabikeguy

Active Member
Joined
Sep 30, 2006
Messages
1,929
japat

My nomination for "augiesputtering coffee on the screen" post of the morning !
 
G

gone_fishin

Guest
you were almost dead-on! :LOL:

my opinion about vibration: these lil happy-times have no counterbalancing on the crank...allowing more motion ("correct" motor-mounting) will result in an amplified vibration. best to lock it down tight and let the frame absorb as much as it's bulk allows, then deal with the rest by properly mounting everything else on the bicycle.

an on-topic BTW-i ran my first 70 for 8 months and approx. 2500 miles (including my all-day 165mi affair) on all-original hardware...never lost one nut or broke one stud...proper install and diligent maintenance are the only reasons i have to explain it. that engine sits in a box waiting for a new home, and i'm sure it'll easily put out another 2500 miles.
 

drimpact

Member
Joined
Apr 23, 2007
Messages
506
I keep a 10mm wrench in my back pocket when I ride. Before I ride I check everything (Preflight), When I stop to take a break, I allow the motor to cool down then check everything (in-flight). When I get home I let the beast cool down and check all the nuts and bolts (post-flight).

Vibrations are a killer, but with my trusty 10mm in hand we are up to the task. I have found the motor mounts to be the most susceptible to loosening, During my checks I make sure they are tight. Early on in my motored bike days I learned the hard way about the ever loosening nuts and studs and had a similar motor mount failure. Since my pre, in, and post checks were put in place I have not had near the problems. It is easier to tighten something than try to find it or its replacement after it has fallen out.

minibiker, don't feel bad about it, take it as a lesson and check, double check, then check it again when you get home. Its all a part of riding a happy times.
 
A

atcspaul

Guest
i did not drill thru my frame. i figured 2 bolts were better then one. bought an extra clamp at automotive store. took out the 6mm theads and changed them to 1/4 after i taped the hole and bought a length of threaded rod and cut to length and around that i used steel hollow tube close to the same size for strength. i also used permentant locktite on those bolts and not removable. with heat you can remove the perment ones. i am aproaching 400 miles which i may hit today if not i will tomorow and never had to touch my mounting screws. every other screw yes lol
 
J

japat100

Guest
my opinion about vibration: these lil happy-times have no counterbalancing on the crank...allowing more motion ("correct" motor-mounting) will result in an amplified vibration. best to lock it down tight and let the frame absorb as much as it's bulk allows, then deal with the rest by properly mounting everything else on the bicycle.

has anyone tried setting these motors in hard rubber .. i can"t imagine why it would not be allot better ,,with no counterbalance you would think it would be more important to have good mounts ,, if my motor was perfect balance i would not need any mounts ,, so i wonder do you all agree with augidog"s opinion ??,,i am trying to design mounts set in hard rubber ,and if augidog is right i best forget it,, and save me time and money
hope to hear back from some members and get there point of view
japat
 
A

atcspaul

Guest
i have rubber strips around each mount. i think hard rubber would worry me. between heat from motor, dripping gas and everything else they would not last long and dry rot. i may be wrong but that is my thoughts
 
Top