My 66cc cracked! what do i do! clutch doesnt work properly!

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Joey

New Member
Sep 29, 2010
58
0
0
Australia, Syd
But you'd better get that air leak fixed quick or the broken place will be the least of your worries.........seriously find and fix that!
How would i fix it if i find a air leak?
and is there any other way of finding a air leak? maybe wd40 would help?
or would i have to get something else?
 

chrisme

New Member
May 30, 2009
423
0
0
Maine
As I said before, carb cleaner and spray it at the points where air would leak in. The connection between the intake manifold and the engine. And the intake manifold to the carb.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
And how would i fix these points?
put a rubber thing between them?
tighten it?
There is a good chance that the leak is at the intake gasket, and WD-40 is great for finding leaks, if you have the original intake gasket on your engine the intake gasket was junk to begin with so I would replace it.

Go to your local auto parts store and buy some fuel resistant gasket material about 1/16" to 3/32" thick and make your own gasket from it, then use a good fuel proof gasket sealer on both sides of the gasket, preferably something besides silicone, I dont like it for intake gaskets on these engines myself, it isnt as good as a good contact cement type aviation gasket sealer, Permatex make a very good one that I use and have never had a failure while using it.

make sure that you get all of the old gasket material scraped off of both surfaces, then get a ball peen hammer a very sharp knife perferably an exacto type if you have one and a pencil for marking off the bolt holes for the gasket while laying the intake on the gasket material, after you get the bolt holes marked off go ahead and cut them out so that you can put a couple 6mm or 1/4" bolts through the holes to keep the material in place and then take the hammer and with the rounded end gently tap around the edge of the intake opening until you can see a clear marking on the gasket material and then you want to cut on that line, you can do the same on the outside of the flange if you like but the shape of the out side is really not important.

Now, before you put the carb. back on the intake you will of coarse already have the intake bolted up nice and tight on the engine with the good sealer on both sides of the gasket.

Now you can use a little silicone....put a dab on your finger and where the carb. slides onto the intake smear a nice good film of slicone all the way around the intake tube but dont get any on the inside of the intake tube, and when you go to put the carb. back on, hold it so that the carb. is not in the upright position, have it slightly tilted when you push in into place and after in has bottomed out on the itake tube then rotate it into the upright position, this will ensure a better seal by forcing the silicone into the slots on the carb. neck. now make sure the clamp on the carb. in good and tight.

This is how I always install the carbs and have not had a single air leak yet.

Either one of the sealers pictured below will work great or something else that serves the same purpose and is fuel safe just avoid using silicone on the gasket, in my opinion it's not nearly as good of a gasket sealer, I had it fail on me many times over the years, so I only use it for little low stress area things normaly because it tends to push out rather than compact and stick.

I know this is a lot of text here but it's the only way I knew to try to make these things clear and hopefuly understandable. Hope this will help you resolve this air leak.

Shan
 

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Joey

New Member
Sep 29, 2010
58
0
0
Australia, Syd
Ive sealed the air leaks today and it runs perfectly!
idles perfectly and heaps of power,
but heres another problem ive tightened it heaps yet the chain still randomly falls off :l
i have no clue what to do..
 

chrisme

New Member
May 30, 2009
423
0
0
Maine
Make sure the engine sprocket, idler, and rear sprocket are all lined up! And make sure the rear sprocket doesn't wobble, that'll throw the chain off too. If it's all lined up on the same plane it won't jump off. If it isn't, it will jump off.
 

Joey

New Member
Sep 29, 2010
58
0
0
Australia, Syd
Well, the engine is also on a chopper, so i cant get it perfectly inline with the sprocket..
and i will try and see if my rear sprocket is wobbling, should i just put up with the chain dropping once in a while?
or would it be bad?
 

Mojo

New Member
Dec 26, 2011
60
0
0
33755 Clearwater Florida
This is a great forum! i wish i would have found it before!
Some background into the bike.
it is a chopper, with a 66cc engine, bought 2nd hand for $250 hard earned dollars..

I really need help with this guys.. please help me,

at high speeds, the engine suddenly revs up very high, and then the chain drops and the engine dies..
also when i stop and hold the clutch down it revs extremely high when its completly stopped!

Today i was riding along and my chain suddenly fell off the sprocket.. and when i checked.. the $#@# thing was CRACKED!

The crack is under the clutch clover thing where i circled..
what can i do to fix it?
or would i need a replacement engine?
or can i weld it together?

PLEASE HELP ME!
ive been running into soo many problems with this bike..

thanks guys
i had this same issue straight out of the box with my Z80 from Boygofast motors on ebay, i would bump start the engine via peddling ride for a split second or two then VERM VERM! sudden extreme rev's in RPM followed by the engine killing off,

i first tightened my Cluctch cable ''witch is clearly the first thing to try''

and attempted another run with no change, it went into high rpm range then shut off,

i pulled the clutch case and took a look... all is good in clutch case.

it turns out that under the Smaller sized gear if you remove it ''drive chain gear?'' anyway if you remove the gear there is a groove cut into the shaft witch it screws too,

there is also a groove in the inner hole of the gear its self there *SHOULD* be whats called a Woodruff key in there witch looks like this http://www.chinesemotorcyclepartsonline.co.uk/images/largeimages/120905004.jpg

i only know this cause when i opened the crank case it fell to my feet lol it was some what of a pain to wedge back in there, in fact i tried a few times, the first three attempts i did not get it all the way snug and fit,

So when i went to and attempted a test run it cranked over then seconds later reved up and shut off again too my displeasure lol, so i opened the crank case and the little bugger fell to my feet again and the small gear had once again came loose!

if you do not get the woodruff key snug and proper, because you tightened the smaller gear witch locks the key in place it had enough grip too crank over
yet when it began too hit any type of high or mid range rpm

the clutch would slip causes the poor little ole 2 stroke engine to rev up wildly then sputter out like some one hit the kill switch,

just get the woodruff key back in place tighten the smaller gear back down and you won't have to stress the issue again! zpt
 

Mojo

New Member
Dec 26, 2011
60
0
0
33755 Clearwater Florida
i had this same issue straight out of the box with my Z80 from Boygofast motors on ebay, i would bump start the engine via peddling ride for a split second or two then VERM VERM! sudden extreme rev's in RPM followed by the engine killing off,

i first tightened my Cluctch cable ''witch is clearly the first thing to try''

and attempted another run with no change, it went into high rpm range then shut off,

i pulled the clutch case and took a look... all is good in clutch case.

it turns out that under the Smaller sized gear if you remove it ''drive chain gear?'' anyway if you remove the gear there is a groove cut into the shaft witch it screws too,

there is also a groove in the inner hole of the gear its self there *SHOULD* be whats called a Woodruff key in there witch looks like this http://www.chinesemotorcyclepartsonline.co.uk/images/largeimages/120905004.jpg

i only know this cause when i opened the crank case it fell to my feet lol it was some what of a pain to wedge back in there, in fact i tried a few times, the first three attempts i did not get it all the way snug and fit,

So when i went to and attempted a test run it cranked over then seconds later reved up and shut off again too my displeasure lol, so i opened the crank case and the little bugger fell to my feet again and the small gear had once again came loose!

if you do not get the woodruff key snug and proper, because you tightened the smaller gear witch locks the key in place it had enough grip too crank over
yet when it began too hit any type of high or mid range rpm

the clutch would slip causes the poor little ole 2 stroke engine to rev up wildly then sputter out like some one hit the kill switch,

just get the woodruff key back in place tighten the smaller gear back down and you won't have to stress the issue again! zpt
I am sorry, i only read half your post, that does not cover it all, the engine reving then shuting down when stoped while holding clutch in is caused by your idle speed being set much too high witch can also make for a more difficult start up

due too the fact the idle screw controls idle speeds, if set too high it can ware down the clutch pads, and cause the engine to rev and die unpon clutching with a full stop,

ever got the line of a weed whacker caught on some thing when reving it up?, it will almost instantly shut down because the engines throttle is left wide open with gas incoming too the engine so it keeps reving up and the drive sprocket of your bike engine is not moving its the same concept as geting a weed whacker caught on somthing.

if your idle is set too low then it will cause the engine too either shut off due too lack of gas and or air flow, or it will slowly sputter out,

hope i helped a little here lol i have the same issue RIGHT NOW with my bike reving then shuting off at a dead stop while clutching because my carb is straight out of the box from the china facility where it was made,

poorly tuned or better put not yet tuned at all,

clock wise turning of the idle screw will make the engine rev high when you hold in clutch and counter clock wise will make it rev lower i might be wrong either way just fiddle with it untill you see witch way makes it rev up or rev down,

You need to get your engine too rev down from the sound of it as do i, best way ''i know of'' since your bike currently shuts off at a dead stop would be too turn it witch ever way you like first, looking too lower the rpms,

then get on and try to start it, then try out the clutch if its worse, start turning it the other way 1 full turn off the screw at a time untill you are ''in the ball park'' then you can''fine tune it'' if you like

typically it will take around 3-4 adjustments before you reach a good steady idle ''assuming you already know witch way too turn it'' if not more like 4-6 times :)

well worth it thogh ~!~ zpt
 
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tooljunkie

Member
Apr 4, 2012
663
5
16
Manitoba,Canada
pssst.
ever look at the date of the post?i'm sure it was resolved.or dumped.
probably not my place,but chain issues always spark my curiosity.
i had some too.
 

Mojo

New Member
Dec 26, 2011
60
0
0
33755 Clearwater Florida
pssst.
ever look at the date of the post?i'm sure it was resolved.or dumped.
probably not my place,but chain issues always spark my curiosity.
i had some too.
Pssst... i'm sick of all the sarcastic little turds within this forum, i care not when this thread was added it had never been labeled solved for one, for two i was having issues and fell upon that thread and decided too solve a few things being talked about in it,

as for the post date, i'm not sure this forum even shows what date the threads are posted i'm new too this forum, and i have been looking for post dates on nearly every thread i've read,

all i seem able too see is the peoples join dates... not that it really matters it seems more or less that you just felt like whining,

really though why would you whine about me dropping a few words on an older post,

get over it dude... sadly the world is not over.

now this will be my last response too you in this thread as i do not want to get into a poo flinging match, you said what you felt and now so have i, lets go read some ''New'' threads shall we ...
brnot
 

Ibedayank

New Member
Oct 29, 2011
1,171
0
0
Columbia Tennessee
Well, the engine is also on a chopper, so i cant get it perfectly inline with the sprocket..
and i will try and see if my rear sprocket is wobbling, should i just put up with the chain dropping once in a while?
or would it be bad?
until you get it perfectly inline your chain will keep falling off and may bust up you case even more

and yes I saw the date but more people are reading this forum then just the ones that activly post in it
 
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