Ollie.T's Aprilia RS250 rebuild and restore

[Ollie.T]

A really good cleaner is CRC's Clean.R.Carb...it is powerfull stuff so make sure your work area is well ventilated and don't smoke around it.Its also good for cleaning/scrubbing brake calipers and all that gunk in your powervalve housing.

Note to future Ollie.T... Don't try and clean carbs in bedroom after a few beers... It may seem like a good idea at the time, but it makes everything smell a bit funky...

[Ollie.T]

Im not dead!!

(I've just been away lots!! And unfortunately I'm going away again tomorrow for another month or so...)

But new bits!!

[Ollie.T]

Measuring everything up, everything is within service limits, except for the "piston ring free end gap" (which is the measurement of the gap between the ends of the piston rings when they are sitting neutral on a bench) manual says service limit 4mm (doesn't say max or min), mine measure approx 5.5mm. what do people think?

[Fast Eddie]

have you been stretching or twisting the rings?

good to see your making as much progress as me on the 2 stroke build

I'm about to get back into mine since my sidecar is on the north island and I can't tinker with that (someone else is tho! Cheers Nev )

Lets hope we are luckier than Asher when we get ours back together.. hehehe

nah mine'll blow up.. I can feel it

[Asher]

You will have trouble being un-luckier than me. I had to put in a few bottom end after the flywheel decided it would try leave me. Now im chasing an electrical gremlin as its only running on one.

[Fast Eddie]

You will have trouble being un-luckier than me. I had to put in a few bottom end after the flywheel decided it would try leave me. Now im chasing an electrical gremlin as its only running on one.

haha, the bonus is when I have a problem I'll just ask you for the solution as you may have already gone through it

[ac3_snow]

Measuring everything up, everything is within service limits, except for the "piston ring free end gap" (which is the measurement of the gap between the ends of the piston rings when they are sitting neutral on a bench) manual says service limit 4mm (doesn't say max or min), mine measure approx 5.5mm. what do people think?

You will lose some compression if the ring end gap is to big. May want to go to an bike/kart/engineering shop and get them to measure the clearance of the bore and piston to cheque you don't need to next size up (I'm assuming you can get oversize pistons etc I don't actually know with these)

[Ollie.T]

good to see your making as much progress as me on the 2 stroke build

Well between work, getting married, buying a new house and going to Samoa for a month, there hasn't been that much spare time!

In regards to the piston rings, the clearances are correct while in the cylinder - it's just that the measurement when it is sitting on the bench (which I guess is a indicator of spring tension when it's in the cylinder) is greater than it states in the manual. I figured that it would only matter if the spring tension was less that stated specification as that would lead to blow by and loss of compression?

So yeah, pistons and cylinders are back on, torqued down - now it's just the carbs I need to try and understand... That and I hope all the bits made it across in the move - cant seem to find the exhaust pipe flange bits! Anyone got any spares?

[ac3_snow]

ahh I missed the 'free' part of your statement. Never even knew that was something that had a measured tolerance, I only ever thought the clearance in the barrel mattered.
Good to hear your getting close though!

[imdying]

There's nothing to understand in the carbs, just give them a bath in an ultrasonic cleaner, confirm all the jets are as listed in the manual, and set the idle stop. Then fire her up!

Given that you're taking a methodical approach and checking/measuring things, you'll probably have no trouble. Generally it's only when you take a rough n ready she'll be right approach that things come bite you in the arse.

Make sure the plastic 'nuts' that go into the carb body for the choke cables aren't broken; common source of an air leak that melts pistons. Use the airbox, filter, and lid, and make sure the little filters on the solenoids are clear.

[Ollie.T]

There's nothing to understand in the carbs, just give them a bath in an ultrasonic cleaner, confirm all the jets are as listed in the manual, and set the idle stop. Then fire her up!

Given that you're taking a methodical approach and checking/measuring things, you'll probably have no trouble. Generally it's only when you take a rough n ready she'll be right approach that things come bite you in the arse.

Make sure the plastic 'nuts' that go into the carb body for the choke cables aren't broken; common source of an air leak that melts pistons. Use the airbox, filter, and lid, and make sure the little filters on the solenoids are clear.

And there is the probable source of my seized piston I had been worrying a bit about why it had eaten itself, and that it would do the same when it's back up and running - however one of the plastic nuts had split (so actually the very first thing I did was replace both of them...)

And what are the little filters on the solenoids?

Managed to get home for a day, powervalves are in and set up according to markings, pipes are on, radiator is on and connected up, brakes are on (except reservoir, which needs replacing).

So it really is just finish the carbs and replace fuel lines, carb filters!

[imdying]

They are nothing more than a round plastic cap with a piece of foam inside. It's the round part of hte solenoid... that's the air inlet, and that round bit is the filter. If you look closely, you'll see how to take them to bits (just the round bit, although you could give the solenoid 12v and blow through it).

[Ollie.T]

Does anyone have a spare front brake reservoir? Bike shops say there is nothing in the country that will fit and I don't really wanna order it online by itself...

[imdying]

So long as the outlet pipe is the right OD, you can use anything, doesn't have to be RS250. Just get yourself whatever you like from a wrecker and order one up next time you're getting some bits. Eurowhatsit is the NZ Brembo guy, he'll probably have a universal fit one in stock. FWIW, my RGV one was the same as GSXR750, so don't neglect looking at things like 916s etc.

How did you get on with the solenoid filters? Had they decomposed?

[Asher]

Are they the same as a RGV? i have a spare