a friend asked me to fix a bike...

[andym]

A couple of days ago a friend asked me to see if I could fix a bike for him as it was making a nasty rattling sound when it was running...

Hopefully someone here will be able to give me some advice, or should I just tell him it's not worth the effort and scrap it?

I've attached a picture of what it should like, I don't want to show how it looks now though.

As far as I've been told it's been on its side a few times and one of them it was left running for a while.... also it has been thrashed and in its 5 year life it's done a very hard 10000 miles but because the dials only occasionally work I'm not sure how accurate this is.

As I said It was supposed to have a nasty rattle from it, but a quick check of the plug and taking of the easier parts of the engine apart it all seems OK.

The things I have found wrong with it so far are:
The air filter was filled with oil, (Now cleaned and replacement filter put in)
The carb has been stripped, cleaned and rebuilt, (small jet was blocked)
Engine had almost a litre of oil too much in there, (drained and topped up to right amount, but while draining what can only be described as half a plumbing compressing ring fell out, also a lot of metal filings on sump plug)

I've had a bit of a tinker with the settings of the carb, now it runs (when warm), sounds OK, (still haven't heard the nasty rattle from the engine).

Anyway the reason for this post, the problem I've got now that I can't seem to figure out, After the bike has warmed up, and will stay idling, When I pull the clutch in there is a fast whup whup whup sound which cuts the engine out unless I twist the throttle.

I have taken the engine covers off and there is no foreign objects in either side of the engine, the only thing that I could find so far was the clutch bearing seemed to every now and then when turning it by hand.... best described by either a bit of grit stopping it until forced to move (not a lot of force), or a flat spot on one of the ball bearings (if that makes sense).

The bike is in a very sorry state, but any help here would be appreciated

[P.addy]

I have one of those

Odd buggers to work with

What noise is it exactly? Where abouts is it coming from? Mine is making an odd clutch rattle, doesn't change when I pull in lever though.

[st3v3]

Current pics?

Can't do any harm...
____________________
Roger wrote: Women don't get damp for clingy puppies. Get some better happy pills, hit the gym & buy a medallion the size of a dinner plate. Job done

[Walloper]

Council Skip It.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[P.addy]

[andym]

not sure about skipping the bike just yet.

Anyway the sound when the clutch is in is like pushing wood through a circular or band saw.

With the rear wheel up it does seem to spin quick, but just not right.

Also there is a little 8 shaped washer that holds the throttle cable in place at the handlebar which is bent out of shape and allows the cable to move around a bit. Could this be the reason that maximum throttle is somewhere around mid twist?

[mysterious_rider]

When you pull the clutch in it cuts out? Would that metal thing that came out not be something from the clutch??

I'd be tempted to check the clutch over...

Otherwise, keep the bike!!! Engines can be had for about £ 70 second hand or about £140 brand new!

Go all out and slam a 140cc in there.

All pitbike engines fit.

[st3v3]

It's not a pretty bike, but a ride is a ride.

I'd take off the minimal amount of parts you can to see what's visibly causing any problems, can't make it any worse can you?
____________________
Roger wrote: Women don't get damp for clingy puppies. Get some better happy pills, hit the gym & buy a medallion the size of a dinner plate. Job done

[Walloper]