My exhaust is broken, take a look at the pics

[doctorprox]

Ive been having a lot of trouble with my yamaha zeal 250. It wont go over around 90 kph, it just loses power like its out of fuel or something, and once i get to that kind of speed it gets worse and continues to keep cutting out at 50-60kph and below.

I heard a rattle from my exhaust and i feel hardly any gas coming out. Also the top can has really hot smoke, and the bottom can has cold smoke.
It seems like i can feel pulses of smoke at idle but when i rev it they go away and i cant feel much, just heat. Where is the smoke?

Heres what they look like inside:

and the bits that fell out:


Is this my problem? I thought the stuff in there was just to keep it quiet. Is it needed to run properly?

If so i think ill have to make some new bits and weld them in.
Thing is i dont want to make it quieter, i like the sound it makes, so if they arent needed, i'd rather leave them out.

[vifferman]

Is this my problem? I thought the stuff in there was just to keep it quiet. Is it needed to run properly?

Yes.
No.
Yes. It's tuned for that exhaust (in proper condition), and also it sounds like the broken bits were partially blocking the exhaust flow.

[bugjuice]

wow, nice job of it there
You'd probably be better off looking on ebay or something, for a decent second hand can. To make up bits that will work right and give the right pressure etc, could be a bit tricky. Good on ya for having a go, but sometimes these things can be hassle.
welcome btw

[doctorprox]

Hi and thanks.
Im going to give it a go, nothing to lose except time.
Reason im gonna build it is, firstly i like DIY, and secondly im in the UK and nobody has ever heard of a zeal.

[erik]

Wow, that looks pretty f***ed. Does it look like it's just rusted out, or do you think someone's tried to remove the baffles only to find it ran worse and just chucked the old bits back in? It's kinda hard to see from the pictures.

The bike will probably smoke a bit more at idle if it's richer at idle. The fact that you can't feel the pulses when you rev the engine might just be because the pulses are happening faster, so it just feels like a steady stream of heat.

Are both exhausts like that inside? Have you checked to make sure there aren't any smaller bits stuck down in the exhaust tubes?

The hot and cold exhausts at idle might indicate you need to adjust your idle mixtures and/or balance your carbs. Or it could maybe be due to the exhausts. Or maybe something else, I'm not an expert... :spudwhat:

[TonyB]

Hey I know it all looks like it's obviously the can falling apart that's been blocking things up.....but does a Zeal have an EXUP valve?

[sAsLEX]

my one cold header was due to that plug being crapped out, dont know the exhaust config but ensure all cylinders are running, and the fact one is cold the other hot points towards the fact something is stuck in one

[doctorprox]

Yeah all cylinders are running fine, and both cans were like that inside.
The downpipes are all as hot as each other, its just the gas from the top pipe which was a lot hotter, maybe its blocked.

Theres no exup on a zeal.

Possibly something still stuck in there, because those components have rusted away, i dont think the exhaust has ever been opened before. The plates at the back where that big tube goes are just missing, so either:

• They have just rusted / burnt away completely
• They are in bits down the pipes somewhere
• Bits broke off and blew out the exhaust

I think i will poke some things down the pipes and put some cleaning solution in there, see what comes out.

The performance issues felt to me like the pipes were blocked and when i go fast the gas cant get out so i lose all power for ages until it clears again when i go slow.