Bolt snapped on motor during ride

[Calcutta]

Well wat can i say i was riding out to the track with a mate of mine, doing nothing out of the ordinary, about a quarter of the way there my bike felt like it had electrical probs, ie: the spark plug dying at full capacity, so we pulled over had smoke let engine cool down started it again and it ran well, half way out there my bike started backfiring a little more and louder then usual and the apparent electrical fault had also came back, not only that the engine was operating at heaps hotter temp then usual, so we pulled over had a smoke let engine cool down bit before i get me spanner out and tightened the 2 bolts on the exhaust only to find that they were still rock solid so i had a look at the grub screw i put in the rear muffler to screw into the pipe to hold it into place, that was still rock solid, so we started up again, about 3 quarters of the way there i was slowing down for a left hand corner just clicked into third as heading round corner opened the throttle and my bike just died, to me it sounded like my plug had failed so pulled over let engine cool down tried starting as we was sittin there i could hear a strange noise, i opened my oil cap to find the oil in my engine was smoking and bubbling to the max so i waited around there for another half hour or so before i finally decided yeah i'll walk the bike for half hour or so and let the engine cool down bit more before i try starting it again, when it came time for me to try start the bike again i could tell by the sounds comin outta the exhaust that it was getting fuel and it was trying to run but there was also this other hissing noise on the side , upon closer inspection i found that one of the bolts holding the intake manifold onto the motor had snapped leaving half the bolt in the bolt hole, now i have since gotten the bike home on a ute, pulled the engine out, dropped the oil, now do you think it would be wise for me to open the engine to see if there is any damage done inside if anything has been sucked in, or just try get that bolt out and dont worry bout anything else????,
i am using motul 5100 10w50 semi synthetic racing oil, new oil will be going into the engine before i start it next, would it just be easier to get new lifan125 motor or just rebuild this?

 

[smith#29]

Dont know the answers to all those questions and problems, but you should be using non synthetic oil. And with your snapped bolt, was it possible to see down into the port with just the 1 bolt holding the manifold on? if you couldnt see inside the port, i doubt any part of the bolt would have fallen in there so no need to pull it down. yes it would be easier to buy a new engine, but why buy a new engine when you could spend that money on go-fast bits for this engine and make it more powerful?

hope i answered part of your questions,

cheers,
Smith#29

 

[Calcutta]

yes when i first noticed the bolt was gone the manifold was slightly lifted away from the engine and particles of the gasket look as if to have been sucked in aswell, this bike i am gonna give to my twin nephews for there birthday next year and as this will be there first bike to learn to ride on i dont want it to have too much guts for them so i aint gonna put any Go-fast parts on it, i am actually starting a custom build in the next month or so featuring a 79 model rm 80 fitted out with as many modern Go-Fast parts as i possibly can put on it but still have a stockish 79 model look,

but anyways back to why i am here, from past experiences with people i have known i have came to the conclusion in the past hour while discussing it over a few cones with few boys that the manifold had been leaking for the majority of that ride hence why at the beginning of the trip at WOT (Wide Open Throttle) to me it sounded like a spark plug problem but when i think about it it could have been due to a lack of fuel and too much oxygen in the chamber, after sucking in a few particles of the gasket the gap between the manifold and the port had increased allowing it to backfire up through the inlet chamber as am backing off the throttle at high RPM's,

now for the engine running at hotter then usual temps and forcing the oil to bubble, smoke and turn a black diesel sump oil looking colour in only 6 hours of engine running since last oil change has got me fuked any ideas??? i normally do oil change every 10 hours of riding

 

[Calcutta]

so with all that i have basically came to the conclusion that yeah i am gonna have to pull the head off and have look inside, a 2 stroke yeah i could pull the head and barrel off inspect it all put it all back together and have it running again in a couple of hours, this however is my first 4banger that i have ever done and was wondering if anybody out there has a workshop manual that could be uploaded or if anyone knows of any links to a detailed workshop manual so i can work out best way to take the overhead cams off and get head off and then how to correctly put all cams back in making sure they in allignment with timing of engine

 

[Pittin]

Having only 1 bolt on your manifold ISN'T real good especially if its leaking air. If air has been entering I can almost guarantee the bike has been running extremely lean which isn't good. Check your plug, if it is white its been running way lean and that will cause the motor to overheat.

To get the bolt out, just try get it off with a stud remover or if worse comes to worse cut it off, drill it out and then tap the thread again, but you will need to use a helicoil so try get it out before resorting too that.

Fix the manifold get some new oil and a new plug, see how that goes before splitting the motor. If its blowing smoke then pull it down and youve either scored your bore done you rings and piston could be anything lol.

 

[Calcutta]

the bolts snapped off half way down inside the thread so i'll have to drill and tap it wether i like it or not as got no other choice, the plug isnt white yet it isnt black either its a halfway colour, i wont be able to get a tap and drill for the thread till after the weekend so will have to wait till then to see if i can get it sorted

 

[numroe]

... was wondering if anybody out there has a workshop manual ...

I wondered the same thing and looked for a manual to download. No such manual. I got the cam adjustment advice from Ken@MSO but otherwise just winged it. It's not too hard. This older posting by me explains my own head off/on process. Worth doing in your situation I'd say.
http://www.miniriders.com.au/forum/tech-talk/18239-need-help.html#post172896

btw: On the cheaper china bikes, it's a good idea to replace all the supplied fasteners with new ones. Not only are the stock bolts often of dubious quality but they are often torqued incorrectly. When torquing them use loctite on ones which are no supposed to come loose. If you complete the manufacturing of a china bike, then you will 95% of the time end up with great value, and I mean great! Otherwise you run with your luck.

 

[Calcutta]

OMG Calcutta,

you could write a book with that Long story up the top LOL jk's.

Me, being a lazy ass haha, i would take it into a bike shop and get them to fix it...(or have a look at it at least)

lol i am actually in the process of writing a book at the moment, i wonder if i could fit that in there somewhere, or other famous stories and stacks of mine like the classic i done a few weeks back on this same bike, was riding along side cane train bridge, misjudged it, over balanced it, put right foot down only to find nothing there but space and the bike starting to go over the edge of the bridge so wat was a person supposed to do? the only thing i could think of was jumping off the bike letting it tumble to the rocky bottom whilst i hang off the edge of the bridge waiting for the bike to tumble down the hill enough for me to jump off and roll down the hill without landing on the bike, yeah i think that could fit in there aswell lol, let me see wat happened to the bike, well the aftermarket bash plate got wrapped around the engine, i bent the frame, ripped the exhaust outta the manifold, bent the bars down alongside the forks, i think that was it, well thats all i fixed on it before i rode it again anyway, i did replace everything that needed to be replaced on it and more, even got new bolts in places that i thought needed even if they didnt need to be changed upon inspection, even the 2 bolts that was holding the intake manifold onto the ports was replaced, my father is a mechanic and got him to check the frame over after i straightened it but that took 8 hours just to drive out there for him to have a 30 min look over the frame so i cant see him all the time, he gave it the all clear, everything got the all clear after i put it all together when he was in town for a night went out riding several times in past week until this happened yesterday

 

[Calcutta]

I wondered the same thing and looked for a manual to download. No such manual. I got the cam adjustment advice from Ken@MSO but otherwise just winged it. It's not too hard. This older posting by me explains my own head off/on process. Worth doing in your situation I'd say.
http://www.miniriders.com.au/forum/tech-talk/18239-need-help.html#post172896

btw: On the cheaper china bikes, it's a good idea to replace all the supplied fasteners with new ones. Not only are the stock bolts often of dubious quality but they are often torqued incorrectly. When torquing them use loctite on ones which are no supposed to come loose. If you complete the manufacturing of a china bike, then you will 95% of the time end up with great value, and I mean great! Otherwise you run with your luck.

i did put loctite on every single bolt that needed it, if it didnt i also put loctite on it, i am a very very big fan of it, none of the bolts have came loose i always make sure there tight before every ride its just that the bolt actually snapped inside the thread whilst i was riding and am concerned that small fragments of metal, dust and shit etc got sucked into the engine whilst it was still running before it did die on me, i have always ridden 2 strokes, i know 2 stroke engines fairly well, but when i pulled the engine out of the frame and started to pull the head off i came stuck with cam and chain pretty quickly am unsure of the best way to strip it and put it back together, other then this i have been overal very happy with the bike yeah fair enough it can be a dog to handle but i know that is only from the small wheels

read that link, was helpful thanks

 

[numroe]

i did ...

Yeah I understand. That's why I suggested new bolts. They wont break like the stock crap (often cast) SS bolts. And also I tried to help you via posting a link to instructions on how to remove and reinstall the head and cam chain.

 

[Calcutta]

i did read that link but it wasnt until after i posted the comment above, i did find it very helpful thanks

 

[corey58]

but you should be using non synthetic oil.

synthetic oil is fine and will not hurt it one bit.... we us it in all our race bikes and never get clutch slip at all, also when we rebuild the motors all the cams, bores, heads all look brand new

 

[nugget]

just throw a helicoil in, and get a decent 8.8 bolt and shouldnt brake no more..

 

[Calcutta]

lets hope so nugget,

that is very helpful to know cheers cory

 

[Calcutta]

well on fri night i thought fuk it, i packed my motor up packed couple sets clothes and decided to pay a visit to me father's workshop, after drivin for nearly 8 hours i finally arrived at his house, upon arrival the first thing i done was put my engine on the workshop bench and told him the story, so we drilled the snapped bolt out retaped the original thread, got hold of some hi tensile bolts cut them up to make studs, have put some permanent strength loctite onto the studs and screwed them into the holes that the bolts used to go into, now when i put the manifold back on all i have to do is put some nuts onto the newly modified studs and i shouldnt have anymore probs with them again, now as for the engine overheating, when the engine is running lean the engine will always run at a hotter temp then if the idle jet mixture screw was spot on, so that explained why my oil turned black diesel sump oil colour in only so little hours of running since last oil change