Engine Rebuild

[unrealone]

Hi all,

Looking to embark on a Top End Rebuild (Possibly Bottom End too if it needs it) for the Aprilia RS250.

I'm after some specific information from anyone that knows or has done one on these bikes?

I'm also interested in upgrading some other parts around the same time. Typically I'm looking at popping an Arrow system on, jetting and dyno afterwards - braided lines and a new chain/sprockets. But what other things can I look at doing within the engine (I'm not looking to do anything real hardcore) - seeing as the bike will be out of action for a few days and its going to take a few weeks to get parts.

Any tips and tricks are warmly welcomed - note I am not doing this one myself as I only have a basic knowledge of mechanics! My local bike shop just dont know enough about this to help me so I come to you my fellow KBers!

Cheers!

[SimJen]

Relatively easy to put new pistons/rings in a two smoker. Just be sure to use new gaskets, don't force anything, and always use new circlips to hold gudgeons in (don't ask me why, but it was costly!).
It would pay to have someone with a little knowledge watching over you, any bike shop should be able to do it though, its simple as!
Perhaps they don't want to share their secrets?
Its definately not rocket science!

Porting the barrels would release a few more ponies along with the Chambers and rejetting....porting is not for beginners though, and you could easily turn your barrels into expensive paper weights!

[SimJen]

Of course the Aprillia RS250 uses the same motor as the Suzuki RGV250.
So try here:
http://www.rgv250.co.uk

[imdying]

Visit here.

You want an entire top end rebuilt kit. You want to inspect your powervalves for any evidence of cracking around the dowels. The RS250/Late RGV ones are stronger, but not indestructible. The tuning works can supply you with billet replacements if required.

All that other stuff is neither here nor there, just buy what rings your bell. You will notice that TTW sells tyga performance pipes for them; they appear to have a good reputation for value for money.

In fact, they can probably sell you everything you're after.

[unrealone]

Thanks for the fast replies guys! Appreciate it heaps. I will spend my very "busy" day at work checking this all out.

[unrealone]

Question: What do you think about the Bottom End? Pretty much inspect it when they go to do the Top End or is it a sort of 'do it anyway' thing? I take it theres probably not much point in doing the Top if the bottom is in arse condition.

[SimJen]

Bottom ends usually last very well, I wouldn't bother unless its already a high mileage motor.
Back in my NSR days, bottom ends used to be good for 80,000km+ "IF" they were looked after (ie good oil, warming engine before riding etc).
I've replaced a few cranks in my time, but if the bike is a known quantity and runs well as is, then just replace the pistons, rings. Check the bores for scoring, possibly clean up the ports a little, put chambers on and rejet to suit. It'll be good for another 5-8hp or so if you're lucky.

[imdying]

What's the general condition? Did black sticky oil come out of the gearbox? If it did, that's a sign that it has been neglected. The workshop manual will tell you how to check for bottom wear I would expect. That book would be my first point of call, plus plenty of the rgv250.co.uk guys are really helpful.

[unrealone]

Bikes only got 21000K on it. Always warmed it up thoroughly while I've owned it. Are there any real indications I might feel/hear from the bike that would suggest the bottom end needs doing?

Edit: Just read your post imdying, I'll post on the rgv250 forum. Nothing leaking out of the gearbox and its been going well for the last 4000ks

[SimJen]

Should be fine, unless its making knocking sounds or something.