Ollie.T's Aprilia RS250 rebuild and restore

[Kickaha]

don't panic yet as a light rub down with very fine sandpaper and kerosene should remove what looks like a bit of melted piston on the cylinders nikasil lining.Lets hope the nikasil has not been scored up at all especially on the exhaust port bridge,coz then you will be looking at re-nikasiling...not cheap.

Muratic acid is easier and what most people use, to replate will be $550-600 at least

sort your quotes out will ya, you missed the / out, makes it a prick to read

The esiest way to remove aluminum from the wall of a nikasil
plated cylinder is with muriatic acid. I believe muriatic acid is just diluted hydrocloric acid (HCl). You can get it at most any good hardware store or swimming pool supply store. Muriatic acid is used to clean lime deposits
in swimming pools, etc. It is commonly available and only costs a few dollars per quart. A quart is roughly a lifetime supply. CAVEAT: be very careful! The acid eats aluminum very quickly! You must be very cautious when using it near cylinder ports...it can eat the aluminum at the edges of the ports. It can also eat aluminum through any nicks or holes in the plating. I usually use a cotton tipped swap to apply the acid precisely where I want it on the nikasil liner. If it causes bubbles, then it is eating aluminum from the surface of the nikasil. I leave it on for about 20 seconds and then wipe off thouroughly. I usually repeat the process two or three times to be sure I have removed all of the aluminum from the plated cylinder wall. Then I rinse the cylinder *very* thouroughly with water to make sure there is no remaining acid. Then drench the cylinder in WD-40. Then a little work with a scotchbrite pad. Then a final cleaning and ... viola! Ready for assembly - good as new.

[eelracing]

Tried the impact driver, no luck, tried butane pencil torch then impact driver, no luck. My bro is mates with a few engineers, so just get one of them to do it.

Fair enough

I'll try and clean up the cylinder... Was really hoping that I wouldn't have to get new piston... it means a few more weeks and less money, which Im trying to save...

And you send shit to RT???

I was planning on trying to get ~2000km more out of this set of pistons and then doing the 1.4mm gasket mod when I rebuild again. You reckon this is asking for trouble?

Not replacing piston?...yes.1.4mm mod?...I look forward to seeing your results.

And how to remove the solder? heat it up with butane torch and try and use something to wick it out? I guess it depends how deep it is...

Sounds sound.



And I shouldn't worry to much about getting solvent type stuff around the brake pistons? I thought that was something to avoid?

I've never had a prob with CRC Clean R Carb.

Muratic acid is easier and what most people use,

Cheers for that.


to replate will be $550-600 at least

Tell me about it.

sort your quotes out will ya, you missed the / out, makes it a prick to read

Hows that?

[eelracing]

For OllieT. and FastEddie...start-up today.Gotta love that Eu De Two Stroke eh?

[Fast Eddie]

For OllieT. and FastEddie...start-up today.Gotta love that Eu De Two Stroke eh?

its my favourite cologne!

mint bro, can't wait til I'm doin that with my 250!

[Fast Eddie]

good work Ollie T - let us know how u go with cylinder clean up - they look worse than mine and u shud see the pistons i pulled out of mine haha..

id be interested in a diy clean up tho..

I had same problem with powervalve screws and also the little allen retainer screws for the actuating shaft and arm. an engineer did 1 allen screw for me, had to drill it out and had to buy new shaft and arm after I made a mess of it trying to get it out with an easy-out.

The rest I did myself with a heat gun.. beefed up blow drier lol.. warmed the whole area up for quite a while, heaps of penetrating oil, gave everything a solid crack with a solid screwdriver/allen head and rubber hammer and then they came out fairly easily. I used an impact driver for a couple but mine wasn't that effective compared to just a normal rubber mallet and a solid screw driver and just give them a crack. heaps of penetrating oil aye. I got the allen head powervalve screws etc from TTW. they rave about them so hopefully they are better for the next removal.

the manual has all the info for setting up the carbs - fairly easy - its probably just the float height which is straight forward and the idle and a synchronisation that you'll do and cleaning the jets - my overflows are not blocked off. and inside of carbs should be nice and clean - I had what looked like sand in one of mine, gotta clean it all out and clean all the fuel and air pathways/jets out too. I used thin wire and air. Havent had them running yet so i might have stuffed em up. who knows.. they look cleaner

have u got the rgv engine manuals? better to go off than the italian RS one.

[Fast Eddie]

oh and what did robert taylor do to your forks and how much was the final bill? I need to do something with mine as well, can't just anodize em and leave the internals shite haha

[Ollie.T]

Final bill from him was $556. He switched the stanchions round with the ones I supplied, modified the spring (he didn't have anything aftermarket that would suit ) replaced all the seals, fluids etc and set up for my weight. Price wise it's about what bike shops quoted me, so I'm cool with that.

[SVboy]

To get the hard to shift crap off your caliper pistons use the edge of an old credit card-no chance of scratching a piston, although yours might benefit from a split, clean and new seals. You could probably use your existing credit card because it will be well f#@ked after your buy new pistons,rings and power valves!! Loving these threads!

[Ollie.T]

Yeah they probably could do with new seals, however from my trawling through of old threads, they are as rare and as hard to find as.... A two stroke with no mechanical problems?

Brembo or Aprilia or someone prefers you to replace the entire caliper rather than rebuild them. Some liability thing or bollocks like that.

And yeah, it's looking like it is replating or new cylinder time, god damn it. And if I'm doing the pistons, I probably should do both. Now to save up another $900ish right?

I havnt even seen the power valves yet. I think it may be off the road a wee while longer...
Perhaps I shoulda bought a H***a!

[Kickaha]

Brembo or Aprilia or someone prefers you to replace the entire caliper rather than rebuild them. Some liability thing or bollocks like that.

You can get rebuild kits for a lot of Brembo stuff, what size are the pistons? and what is the spacing between the mounting holes onto the forks?
This is one of the most common kits https://store.bevelheaven.com/brake-...ston-seal-kit/

hmmm you might be right going by what he is saying

[tigertim20]

And yeah, it's looking like it is replating or new cylinder time, god damn it. And if I'm doing the pistons, I probably should do both. Now to save up another $900ish right?

I havnt even seen the power valves yet. I think it may be off the road a wee while longer...
Perhaps I shoulda bought a H***a!

isnt there a 300cc kit available?

[Ollie.T]

You can get rebuild kits for a lot of Brembo stuff, what size are the pistons? and what is the spacing between the mounting holes onto the forks?
This is one of the most common kits https://store.bevelheaven.com/brake-...ston-seal-kit/

hmmm you might be right going by what he is saying

So, now I need to save up another $1050ish...

I was hoping to get new pipes later this year, they probably off the cards now...

[eelracing]

This is pretty much the first time I have pulled a bike to bits - the most mechanically minded thing I have done before this is probably take off the front wheel, adjust the chain tension and occasionally change the oil! So yeah, its probably going to be a bit of a learning curve...:

Yeah they probably could do with new seals, however from my trawling through of old threads, they are as rare and as hard to find as.... A two stroke with no mechanical problems?

And yeah, it's looking like it is replating or new cylinder time, god damn it. And if I'm doing the pistons, I probably should do both. Now to save up another $900ish right?

I havnt even seen the power valves yet. I think it may be off the road a wee while longer...
Perhaps I shoulda bought a H***a!

So, now I need to save up another $1050ish...

I was hoping to get new pipes later this year, they probably off the cards now...

Ollie the education you've given yourself already is something that 90% of motorcyclists will never do so congrats for getting this far.
Realistically you have a nearly 20 year old bike and in a world where mugs like me are paying close to $600 for a years rego it is a small price to pay in the long run.

Your RS when on the pipe will carve up back roads with the best of moderns and not many 20 year old bikes will do that...hell don't even mention modern 250's,but that's so called progress for you eh.
Lay her up for winter,treat her to all of the above (forget about the 1.4mm barrel mod for now unless you want to go racing,these bikes really don't need it)and remember you have a performance stroker in your garage and not a plug in and play, ride and forget toy.

[Ollie.T]

Ollie the education you've given yourself already is something that 90% of motorcyclists will never do so congrats for getting this far.
Realistically you have a nearly 20 year old bike and in a world where mugs like me are paying close to $600 for a years rego it is a small price to pay in the long run.

Your RS when on the pipe will carve up back roads with the best of moderns and not many 20 year old bikes will do that...hell don't even mention modern 250's,but that's so called progress for you eh.
Lay her up for winter,treat her to all of the above (forget about the 1.4mm barrel mod for now unless you want to go racing,these bikes really don't need it)and remember you have a performance stroker in your garage and not a plug in and play, ride and forget toy.

Yeah, im gonna forget about the barrel mods right now...
I do enjoy the fixing side of things - I just wish it wasn't quite so hard on the pocket!

Here are a few photos of the forks... Im away (fucking AGAIN!) for a bit, so progress is gonna slow right down (though I have taken the carbs with me )

[Clivoris]

Great read mate. Keep at it.