125 not liking me throttling up

[digger1985]

Hello all,

Relatively new to biking and very new to mechanics! Thought i would try something easy like removing my 1 piece exhaust from my copy CG (to make it look pretty/prevent any beginnings of surface rust from worsening), but it seems I've caused some problems!

I've put it all back together and now it wont idle smoothly and it cuts out when I snap the throttle open. I replaced the gasket between the down pipe on the engine.

Any ideas what I may have done wrong/what the problem might be?

It was running lovely before I did this - took it on a 100mile round trip with not even the slightest issue.

Thanks, Tom

[The Artist]

Probably not sealing properly. Can you feel a leak around where the exhaust seals to the engine?

[RIDINGforKICK...]

What did you actually do to the exhaust when you took it off?

Did you pressure wash it?, could it be full of water?

Is the exhaust leaking at all?

Have you tried riding it, yet?

[digger1985]

Felt for leaks and there doesn't feel like anything is coming out.

When I took it off I cleaned the outside only with ovencleaner just to get all the crap off, put some hammerite rust stuff on it to clean it up a bit, then sprayed it with BBQ paint. It wasnt every immersed in water or any liquid and none of the spray went in either end of the exhaust.

Out of curiosity I tried to fire it up without the exhaust on, and it make a popping noise on start up, then ticked over for about 1 second then cut out. I only did it the once as it sounded evil.

Not tried riding it yet, I'm worried that I'll need to hammer the throttle, for whatever reason, then it'll cut out and i'll die! lol

The first time i tried to re-attach the exhaust I over tightened it I think as the gasket was squashed down when I dismantled it again (because it wasnt working). I havent tightened it as much this time, but it isnt loose at all.

[RIDINGforKICK...]

Nah!

Ride it.

I bet it will be ok, no reason why it shouldn't be.

[andy_uk]

Instead of snapping the throttle open, does it rev okay if you gradually increase the revs?

You need to let it warm up before hammering it...
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Aprilia Classic 125, GS500E, ER5-A1, ER5-C4, ER6 & an XJ6 project frame...

[digger1985]

It does generally rev ok when gradually increasing revs. I just took it out and it was fine when i got going - once the revs were up it was very responsive (ie once i was up to speed and reving at about 8000rpm it would quite happily snap up to 10000) but if I got to lights and came to a stop and put the clutching in and hammered it, it would cut out again. I know this isnt generally something I would need to be doing, but I never had a problem doing it before.

First time ive been out on it in 2 weeks though - it was ace! Despite be misjudging how damn cold it is!

[Rogerborg]

Make a thick mixture of washing up liquid and water, then spray it on your (cold) exhaust. Watch for bubbles. Bodge until no bubbles are seen.
____________________
Biking is 1/20th as dangerous as horse riding.
GONE: HN125-8, LF-250B, GPz 305, GPZ 500S, Burgman 400 // RIDING: F650GS (800 twin), Royal Enfield Bullet Electra 500 AVL, Ninja 250R because racebike

[RIDINGforKICK...]

Exhausts do "coke up" and self seal if the leak is tiny.

If you can't find any leaks with Roger's washing up liquid tip, I'd just use it for a few day's and see how she pans out.

[digger1985]

Will try that tip tomorrow evening Roger!
I think now i've been out on it (and know that it won't affected my riding) I'm not worried about the issue as much, but it still pisses me off cos it was sweet as a nut before I started messing with it!
Thanks for all your help guys, will be back on should it cause me any other issues!

[RIDINGforKICK...]

Might just be cold M8

They do run very differently in different conditions, they're not like a modern car.