50cc moped problem!

#1
I am 16 and have a 50cc moped. I was taking the exhuast today, and as i was undoing the bolt, it snapped! so half the bolt is in the manifold. To make it worse, its snapped flush with the manifold so you cant even get a pair of pliers on it and twist it out! this has really p***ed me off as i am selling it this week!
Anyone got any ideas?
Thanks,
Ben.
 
#2
Flood the broken stub with penetrating oil and leave it to soak in. Dril into the stub to a careful depth and buy a screw extractor - carefully use the extractor bit to back out the broken bolt. Buy new bolt - done.
 
#3
You could
A. do as AAGF said.
B. Lob it back together as best you can, clag the bits together with liquid metal, and sell it as seen.
C. Burn it and claim on the insurance.
D. Pay a workshop to do A.

I'd go for A, or D if you're a bit biff at that kind of thing.

;)
 
#4
http://cgi.ebay.co.uk/EASY-OUT-OUTS-BROKEN-STUD-SCREW-BOLT-EXTRACTOR-SET-NEW_W0QQitemZ220302653248QQcmdZViewItemQQptZUK_Hand_Tools_Equipment?hash=item334b0fb740&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A1689|293%3A1|294%3A50

Cheap set here, perhaps TOO cheap! (You really don't want to break the stud extractor off in the stud!)

You'll need a tap wrench to turn it with too, you'll probably cock it up trying to turn it with pliers or a a spanner.
 
#5
Do what I done,

If you live near a shop that sells nuts and bolts (normally in yellow pages under engineering supplies/fastners go in and get some brass bolts should be about £1 for the 2 these dont snap due to the heat generated from the
barrel)

Make sure you fit a new gasket and pad up the side with some gasket sealant then using a new bolt! tighten up the other side then let it dry should be able to seal it off.

failing that take off the barrel (not too hard) and take it to an engineering shop they should be able to drill out the offending stud for about £10.
 
#7
thanks for the help, what did was i drilled it out and bolted it straight through! but now i have blown the piston up! so got a 70cc bore kit coming tomorrow :p thanks again,
Moony.
 
#8
mooony said:
thanks for the help, what did was i drilled it out and bolted it straight through! but now i have blown the piston up! so got a 70cc bore kit coming tomorrow :p thanks again,
Moony.
Moony
Did you drill into the barrel? I'm trying to figure how you blew? the piston up or was that a face saving way of saying you drilled into it :wink:
And I myself wouldn't use brass on a manifold joint,
fair play to you for tackling the job, but for such a small engine (1) is it worth fixing cost wise?.. and( 2 )could you source a secondhand one?
 
#9
well, what my mates step dads mate, who is a mechanic said, because the exhuast was blowing for some time, it knackered the piston/piston rings, also there was to much fuel getting into it. And no, i never drilled into it lol :)

a quick question, how many miles would you say it will take to run in the new piston?
Thanks,
Ben.
 
#10
mooony said:
well, what my mates step dads mate, who is a mechanic said, because the exhuast was blowing for some time, it knackered the piston/piston rings, also there was to much fuel getting into it. And no, i never drilled into it lol :)

a quick question, how many miles would you say it will take to run in the new piston?
Thanks,
Ben.
moody
I dont know what make it is but I assume it's 2stroke? if that is the case ,,increase your oil to petrol ratio for the first couple of miles, avoid heavy throttle usage and low gearing work, basically just nurse it for a while ....give it a chance,
then revert to correct oil mixture. then roberts your mothers brother.

if it's a 4stroke ie Honda..same thing apart from the need to worry about fuel mix.
 
#11
If its a two stroke then its probably running on injected oil via a pump , don't frig about with the adjustment ! , just don't run it at full revs and more importantly don't make it work hard for a 100 miles or so. The whole big bore thing is a potential problem . Because its now running a bigger piston its likely to run lean on the main jet , you may also have to go up a grade on the plug .
Best advice is fit the kit , ride it gentley and sell the bugger quick , as you seem to lack the know- how to jet it correctly and keep the engine from becoming a siezed mess.
 
#12
It sounds as if he's been running lean could be a number of problems air/fuel mixture too weak either caused by a cracked rubber or blowing carb manifold for a start. or his main jet in the carb may be full of gunge. best bet would be to strip down the carb and get rid of any deposits/flim off the carb slide.
A blowing exhaust will also affect the fuel mixutre as well.

However if your going to fit a 70cc kit you may need to add a bigger main jet to thwe carb to compensate. If you dont expect to heat seize on a regular basis and burn out the odd piston.And you'll jneed to run it in for a period of time unless it's a nicasall lined barrel. best use a good semi synth oil for running it in
 
#14
right, bike has broken again!! went to my moms, bike started first time as it normaly does, Just about to leave moms a few hours later on after watching liverpool lose, bike wouldnt start! tried electric start..nothing. kicked it over, and on fourth kick started,then died straight away. My moms boyfriend had ago at starting it, managed to eventually get it started on electric start. I rode it home, about a 10 mile journey bike seemed fine. When i got home, i turned bike off. Went to try it again later on in the day and it wouldnt start! and i can't get it started. I had RAC come out and they say theres no compression.. which means piston, but i have only just put a new one in(4weeks ago). And if it had no compression, i wouldnt of managed to even start the bike let alone ride 10 mile home. I don't have a clue to what it is, if its not piston then my guess's are on something fuel/carb wise, But i'm no expert. Anyone have any ideas/thoughts?

Ben.
 
#15
mooony said:
right, bike has broken again!! went to my moms, bike started first time as it normaly does, Just about to leave moms a few hours later on after watching liverpool lose, bike wouldnt start! tried electric start..nothing. kicked it over, and on fourth kick started,then died straight away. My moms boyfriend had ago at starting it, managed to eventually get it started on electric start. I rode it home, about a 10 mile journey bike seemed fine. When i got home, i turned bike off. Went to try it again later on in the day and it wouldnt start! and i can't get it started. I had RAC come out and they say theres no compression.. which means piston, but i have only just put a new one in(4weeks ago). And if it had no compression, i wouldnt of managed to even start the bike let alone ride 10 mile home. I don't have a clue to what it is, if its not piston then my guess's are on something fuel/carb wise, But i'm no expert. Anyone have any ideas/thoughts?

Ben.
Get a new one, mate, this one sounds like it's had it.
 
#16
mooony said:
right, bike has broken again!! went to my moms, bike started first time as it normaly does, Just about to leave moms a few hours later on after watching liverpool lose, bike wouldnt start! tried electric start..nothing. kicked it over, and on fourth kick started,then died straight away. My moms boyfriend had ago at starting it, managed to eventually get it started on electric start. I rode it home, about a 10 mile journey bike seemed fine. When i got home, i turned bike off. Went to try it again later on in the day and it wouldnt start! and i can't get it started. I had RAC come out and they say theres no compression.. which means piston, but i have only just put a new one in(4weeks ago). And if it had no compression, i wouldnt of managed to even start the bike let alone ride 10 mile home. I don't have a clue to what it is, if its not piston then my guess's are on something fuel/carb wise, But i'm no expert. Anyone have any ideas/thoughts?

Ben.
No compresssion is not a fuel/carb problem, it's er.. no compression.

Simply, There is a big leak somewhere in the cylinder, so it will be cylinder head off again and have a shufti inside.

Could be a damaged a piston ring. Holed piston. Blown head gasket. or even a warped cylinder head.

All these are faults that can easily be caused by incorrect procedures with repairs and proper "running in" such as you outlined in your previous posts and good information that others here have advised.

As it's a moped, none of the above will be that difficult to diagnose and repair.

If you do not want to take it to a garage, get a Haynes Manual, take your time, use decent tools and stop THRASHING the nuts off the thing after a rebuild.

Be a bit careful about selling a 70cc machine as a "moped" as well.

Don't worry about the moped knockers either. I started my riding on one in 1973, had a blast and am now on bike number 23 regularly riding 20,000 miles a year.

Good Luck
 
#17
Arte_et_Marte said:
If you do not want to take it to a garage, get a Haynes Manual, take your time, use decent tools and stop THRASHING the nuts off the thing after a rebuild.
The good old Haynes Destruction Manual. I rebuilt my Honda 250 using one of those. Ok, it didn't tell you what to do with all those bits left over but I still managed to sell it to a dealer.

Before it seized.
 
#18
Might be a stupid question but check your spark plug is seated in firmly it will give low comprssion as the air travels out the gap. I sold a 180 runner thinking it was a holed piston never thought to check the plug fella got it for a steal as well :x
 
#19
yes checked spark plug, it is bone dry, this would be meaning fuel isnt getting through? I don't thrash it, as it will still only do about 40 mile an hour as it is still restricted on the cdi i think, i have been trying to sell it and it breaks down! off to afc in 2 and a half weeks lol.
 
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