2 stroke losing power/bogging ?

[Medicinal_Motocross]

Hi guys, i am supposed to be getting a Aprilia Tuareg 125 from down the road next monday in need of tlc but i am baffled as to what actually needs doing the guy claims it runs, idles fine but is bogging when about to hit band i guessed could be a number of things reeds, rings need replacing, carb not set up right or clogged even the inlet manifold if its perished badly but he says a guy who is a mechanic told him its the exhaust gasket is this possible ? it has the rotax 127 engine which i know nothing about fitted and dont know if its going to be more trouble than its worth also the starter motor doesnt turn over are the rotax 123 motors the same does anyone know? any help would be great..

[workboots]

You could try cleaning or replacing the spark plug.

[Commuter_Tim]

Or some punctuation

...Oh shit, *I'm* correcting people's writing skills, I think this may be a first, Woooo!
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The above post is most likely nonsensical.

I ride a Bandit 600... badly.

[stevo as b4]

Keith will be along I'm sure with some real Knowledge. But the Rotax 127 motor's are much rarer and harder to get parts for now than the 122/123 motors, I would think?

They used the 127 motor in the early models of the AF1 and the Tuareg etc, but not much else I don't think?

I would think that things like gasket sets, reeds and bearings etc are still available though.

[Medicinal_Motocross]

I realised the 127 engines are getting hard to come by gaskets,pistonshe claims to have changed the spark plug I was going to take it out check the colour its a 1989 so quite a old smoker I'm guessing there isn't to many in UK? I believe the 127 has slightly bigger piston/barrel bore than the 123 and can see rebuilding one of them engines being a real task just due to parts. What should I be listening out/looking for when having a look at it other than rattles from engine guys ?

[stirlinggaz]

hi,
from what i remember the 127 was quite a decent engine....
anyway, does it have the pneumatic pv? then its pretty much the same as any other 2t, just make sure the pv blade is clean & keep an eye on compression, anything less than 115psi, take the head off & have a look.
gaskets,pistons etc can still be had, afaik.
& use the best 2t oil you can afford.
cheers,
GAZ

[Medicinal_Motocross]

Appreciate the input guys, I'm not sure about the powervalve as far as I know its the RAVE system? It has no kickstart and starter doesn't turn over so checking compression would be a game as far as the bogging goes could a leaking/worn exhaust gasket cause this or is it horse crap so I buy it then got another 2t rebuild on my hands? I can't find anything other than gaskets for the 127 on eBay really where could I order parts from that wouldn't rob me blind in case engine is on its way out?

[Kickstart]

Hi

Just seen this post.

Think a few internal bits are shared with the 123, but not certain on that.

The 127 has no counter balancer (unlike the 122 / 123) and the gaskets are quite different. 127 has 4 long studs that go from the crankcase up through the barrel and head (the 122 / 123 has 4 studs holding the barrel to the crankcase and then 5 holding the head to the barrel). The bore is the same as the 122 / 123 but it has a very marginally shorter stroke (54mm rather than 54.5mm). It has a cast iron bore in the AF1 which can be rebored. Water pump intake is on a different side which would be a minor pain if you wanted to swap in a 123 engine.

From memory the AF1 and the Tuareg have different gear changes. Ie, put a Tuareg engine into an AF1 and you land up with a 1 up / 5 down gear change.

The ignition is similar to the 123, but not the same. No advance / retard. I have been told that the 123 flywheel has a different number of teeth for the starter motor than the 127, and while it will work for a while the starter motor chews the teeth up after a while.

If probably came out of the factory with the pneumatic power valve. Check that the rubber bellows are in good condition.

Probably worth giving the carb a thorough clean, checking the ignition timing (can be done dynamically with a timing light or statically with a dial gauge), checking the reed valve condition and checking compression.

All the best

Keith
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