Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
I Have a dodgy intake valve tappet cover on my lifan 125 because I snaped one of the bolts ages ago and couldn't get it out, so I drilled in next to it and I drilled through into where the little adjuster rod and locknut are and metal shavings got in there :/ went for a strap cuz I got the cover on there and was happy with it, it's worked fine for ages buti had a stack and it was a bit loose so I took it off and kept drilling because I didn't have a shorter bolt or a cuttin dics to make a shorter one. It went fine but after a few minutes I stoped for a quick chain tension cheak and it started to idle funny then I heard a huge pop kinda crack sound then it died .. Ive started it since then but it sounds weird, have I screwd somthin in the engine head with those metal shavings?
 

my67xr

Miniriders Legend and Master Spanner Spinning Mode
Joined
Jul 29, 2010
Messages
11,982
Reaction score
79
Location
South Australia

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Can't until get a new phone, still can't figuer out how to post photos (on the iPad anyway) I can get to the option but it only let's me uploaded photos from a URL.

There's no way to change those bearings is there ? Or will I need a new camshaft ? Defently Sounds like that's where the shavings ended up, but what do you think the big crack sound was about? It was idling when it happend
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Yea they always lined up, but wouldnt stay there the flywheel kept pulling it away from the mark soi pulled it off while it was all lined up
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Would the cashaft bearings be usale if I can get the shavings out ? Or would they have mangled them
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
So was that big pop/crack just the bearing seizin up and not letting the engine do its thing ?
 

my67xr

Miniriders Legend and Master Spanner Spinning Mode
Joined
Jul 29, 2010
Messages
11,982
Reaction score
79
Location
South Australia
yeah the bearing might have seized,
the cam chain could have jumped a few teeth, whcih means the valves may have hit the piston and bent.
or the cam chain may have broken, again may have bent valves.
the cam gear bolts might have sheered off, this could bent the valves too if the piston hit them
the rocker arm might have broken
it could be a lot of things

no you won't be able to use the bearing again, a new one would be around $6, there is one at each end of the cam?
then you'll need to have the old ones pressed off, and the new ones pressed back on


or you could buy a new cam off ebay etc

you need to take the clutch cover off the engine too and flush out all the metal filings,
clean the oil filter screen etc too. and refill it with fresh oil.
hopefully the filings didn't damage any of the other bearings in the engine, or the oil pump etc
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Iv runn the engine for a at least five miniutes after this with I really regret doin :/ so they have more than likely have messed somthing up but alteast i know the camchains not f'ed, So split the crankcase and clean all in there to? What do I flush it out with? And I have a cam shaft for another 125 lifan so il use that :) if nothing's broken and I flush it out will it be okay? I should have just cleand the head whenit happened
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Just trying to figure out the best way to go about it before I screw somthin else up
 

my67xr

Miniriders Legend and Master Spanner Spinning Mode
Joined
Jul 29, 2010
Messages
11,982
Reaction score
79
Location
South Australia
you wont need to split the cases,
you'll hopefully get away with dropping the oil, then just taking the kick start lever off, then the clutch cable and clutch cover off.

drain the oil out, undo the clutch cover bolts and take it off, lean the engine so the old oil etc will drain away from the case.
you could buy some Export degreaser or similar and spray it in the bottom of the case to try and wash away anything that's still in there.
if you spray it up and onto the bearings of the gearbox/clutch/crank etc, make sure you oil them all well before reassembling it
pull the spark plug out, and fit the kick start lever on, then push the lever down to turn the engine over a few times and check it isn't all locked up before you reassemble it
make sure you take the oil filter screen out and clean that up in petrol./degreaser too.
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
When I was riding it, it seems like the clutch sloped in or somthing.. Would rev but wasn't goin anywhere.. That's the seized bearing right? Cuz i only got like 50 meters before it started doin that :/ if it still turns over smooth is it okay? I'll drop the oil and see if it's in there
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
And now that I can remember, I did take it for a few laps and then rode home before this happened and it went fine..is there a chance that it could have got chewed up and im In the clear? Because it wasn't Mutch and it was metal shavings from the cast (pretty soft metal)
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Went for a ride before, nothin hectic .. Just a few wheelies.. But I've bugged the float legal somehow? Could it be the bad camshaft bearings ? Can hear that they aren't in good shape, but this has happend twice now, just riding along and the it seems like main jet is clogged but when I pull it all apart the float level is way off, fix it, then happens again :s is there a comon cause of this? Or wouldn't be the gamen bearings
 

my67xr

Miniriders Legend and Master Spanner Spinning Mode
Joined
Jul 29, 2010
Messages
11,982
Reaction score
79
Location
South Australia
the float level won't change by itself, you may have bent the arm when putting the fuel bowl back on
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
if I did that it wouldn't go perfect then just go all s*** like main is clogged after 5 mins ? Somthing is defently stuffin my float level.. Went fine after a big sack, then did this, fixed it again and it has happend again :/ Oly culprit I can thing off is camshaft bearings are screwd.. Can i change cam shaft just buy taking tappet Rods (clearence adjusters) out and taking cam sprocket off? and of corse the covers that I'd need to remove to get at the adjusters and cam sprocket
 

my67xr

Miniriders Legend and Master Spanner Spinning Mode
Joined
Jul 29, 2010
Messages
11,982
Reaction score
79
Location
South Australia
with your main jet getting clogged up after 5 minutes riding, there must be crud in your fuel tank, fuel tap, fuel filter, needle and seat or carby
it cant get in there any other way

and the dirt or whatever is blocking your main jet can't change your float level, you mentioned it keep's changing in a post above

the cam is pretty easy to take out,
turn the engine over to tdc, line up the mark on the flywheel to the mark in the case at 12 o'clock
then check the marking on the cam line's up to the mark in the head at 9 o'clock
the engine is now at tdc
loosen the 3x cam gear bolts but don't take them out.
remove the timing chain tensioner spring retaining bolt from the bottom of the engine to take the tension off the chain
now undo and remove the 3x cam gear bolts and take the gear off the cam
there are 2x shafts that hold the rocker arm into the head, take them out and the rockers will become loose.
remove the heads' rocker cover from the front of the engine and take the rockers arms out
now the camshaft should slide out, and you can check the bearings etc.
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Okay, Before this happened. I - cleaned carb, checked both jets/ ensured they were both clean, re set float level because it was Waaay off ( somthing had to happen to make it do this ). Because I couldn't have put the float bowl n wrong wilst riding? Or changed anything in there without taking it apart ?the main isn't getting clogged, the float is gettin put off somehow.. Only times it's ( changed float level) ever done it before is after a big stack or stall and that's what makes me think it's the dodgy bearings , Sounds like a mish.. taking the adjuster rods at the end of the Rokers all the way out then pushing that end down (lifting the other ends the rocker) release/let the cam loose :) it's easier than taking front and side plate off head and getting them x2 shafts out (done it before ) il change it soon, will it be cool if leav the cam chain tight ? Cbf'ed takin bash plate off to loosen it
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
Just tryin to get some ideas on what could be doin this to my float levle. :) don't really wana go pullin whole thing apart to find its somthing simple or easy as to fix, any other problems that have symptoms of a clogged main jet?
 

Rizzo97

Well-Known Member
Joined
Jul 14, 2014
Messages
324
Reaction score
0
Location
Maryfarms QLD
I know that I am gona have to change the float levle again now to make it g good again but I wana fix wat ever is making it do this also, but I'm still trying to figuer ur what's causing it
 

Latest posts

Top