Aprilia RS250 Project

[MK3 Dan]

alvington89 said:

https://www.all-strokes.com/product-page/aprilia-r...

https://www.rimotoshop.com/gb/chains-ridges-roller...

Thanks but it is the chain guide I am after, not the chain guard - plan to fit the Tyga carbon rear hugger/chain guard for that.

Ordered the eBay chain guide for now so will see what that looks like once it arrives.

[MK3 Dan]

Steve Bass said:

If new cranks are available, I’d definitely take that route. Not cheap but refurbishing an RS never is. I think that’s the key problem here, over their lifetime, the RS needed constant attention, fettling and $$$, something that the average owner couldn’t afford.
This will be an expensive project but the end result will be something very few bikes can get close to… perhaps don’t think of it as an investment

Thanks Steve (will be saying that a lot more in this topic I am sure!)

New crank it will be then.

Ordered pistons today so they should be here Monday and will send Sean an e-mail shortly. Have noted a 10% discount on forum contributors so will do that.

Yeah, well over the investment side and now just going for the best I can. Still don't think it will loose as much as my other projects, providing I keep it for a few years.

[MK3 Dan]

Managed to get a weekend a good few hours on it over the this weekend.

Started with a cleaned up frame. Wanted to improve the shine more but with it being coated/anodised it wouldn't polish up any further.



Got the swingarm all built up with brand new bearings and the Chinese chain guide which finally landed, it seems half decent quality and fits well. Guess time will tell how well it lasts but it was my only option.



Replaced all the bearings in the rear suspension linkage, along with seals. It did not look too happy and few bits of rust on some of the spacers.





Frame and swing arm joined back up:



Replaced the head stock bearings as well, whilst they didnt look too bad they were some signs of wear and I am glad I made the decision to do all of the bearings whilst I was at it.





Got her back up on some stands



Went over the wheels, still want to put a protective coating of some sort on them but was getting carried away with progress. First lot of titanium went on with the disc bolts and rear sprocket bolts - plus a new sprocket. I always think Renthal sprockets look good.



That was how Saturday ended!



Today started with cleaning up and refitting the undertray, along with ECU and CDI



Then cleaned up and sat the wiring loom back in





End of a few hours today



Tucked it up under a new to me cover



Overall happy with the progress and things are cleaning up well. Still plenty to keep me going but lots of bits I dont want to bolt in without the engine, yet to send the cylinders which will go next week so won't see them back until the New Year.

Cleaning the worse barrel up it looks like the plating has come off the bore, not sure if this is due to running lean or a lack of oil. Both carbs and oil pump will be checked/cleaning with new oil and fuel pipe - plus replacing the check valves in the cases and cylinders.

[cirian75]

Awesome work :

[NITO]

Great find for you there, good luck with the rest of the build and nice work.

I had some of the same issues as you, the seized hugger bolt for example!

I expect your carbs may be a similar story to mine. Be careful with the high power circuit elbow off the right hand carb as it is unobtanium now. My left one snapped with next to no pressure through being weakened by ethanol fuel, (it was all clogged up also), which did a lot of damage to the carbs where it had been stood and thankfully I went through them all before daring to take the bike down the road which picked up a lot more issues too with other parts! you're doing the right thing with this approach.

I did a blog for my own sanity documenting it all here in case you find anything there useful;
https://nitosport.com/category/aprilia-rs250-chest...

Edited by NITO on Monday 27th November 14:40

[Steve Bass]

Proper Job

[MK3 Dan]

NITO said:

Great find for you there, good luck with the rest of the build and nice work.

I had some of the same issues as you, the seized hugger bolt for example!

I expect your carbs may be a similar story to mine. Be careful with the high power circuit elbow off the right hand carb as it is unobtanium now. My left one snapped with next to no pressure through being weakened by ethanol fuel, (it was all clogged up also), which did a lot of damage to the carbs where it had been stood and thankfully I went through them all before daring to take the bike down the road which picked up a lot more issues too with other parts! you're doing the right thing with this approach.

I did a blog for my own sanity documenting it all here in case you find anything there useful;
https://nitosport.com/category/aprilia-rs250-chest...

Edited by NITO on Monday 27th November 14:40

Thanks for the info and interesting to take a read through your blog.

I had been warned about the float levels and its interesting to see some pictures and the process that you followed.

I am hoping things are ok on the Ethanol front, it hasn't been on the road here and know its when it was running super was used. Petrol tank doesn't appear to have swollen and that is apparently more of a thing with Silver tanks!

[MK3 Dan]

Got the crank out of the engine during the week and despite all the bearings feeling ok I am going to replace it with a new one.



Also decided at that point that there really isnt too much too these engines and I may as well take it completely apart to clean it up and check over the gearbox and clutch.

Cassette gearbox makes things nice and easy. It looks in really really good condition, next to no wear on the dogs.

Clutch also looks good, just the steel plate has a groove worn in it from the (I presume) anti judder washer so going to replace that.



Will get an oil pump gasket and output shaft gasket sorted next week then get all the bottom end together, waiting on the crank and cylinders.

Cylinders went away early this week with new Pro - X pistons to Sean at Tuning Works who has been mega helpful.

Hopefully have a few hours to tinker with the bike again tomorrow but will be doing lots of smaller jobs so won't see much visual progress.

Start of the Cerakote should be back next week so I can get the clip ons and top Yoke etc on.

[lard]

seeing that frame being cleaned up reminded me of my RS125 I had many years ago, my first and best handling bike!, always coverted the RS250 and loving the progress, thanks for sharing

[MK3 Dan]

lard said:

seeing that frame being cleaned up reminded me of my RS125 I had many years ago, my first and best handling bike!, always coverted the RS250 and loving the progress, thanks for sharing

Likewise, had a RS125 a fair few years ago and always wanted one of these.

[Marquezs Stabilisers]

MK3 Dan said:

Thanks for the info and interesting to take a read through your blog.

I had been warned about the float levels and its interesting to see some pictures and the process that you followed.

I am hoping things are ok on the Ethanol front, it hasn't been on the road here and know its when it was running super was used. Petrol tank doesn't appear to have swollen and that is apparently more of a thing with Silver tanks!

Most super has ethanol in it now, if you see E5 on the pump that means 5% ethanol. Only solution is either get the plastic tank Caswell lined (for which I'd send it to them having done it myself), or get a race spec alloy tank. If these were run at the TT someone somewhere will have made one.

[MK3 Dan]

Ordered up the replacement crank this week - due in Feb :-( from what I understand Suzuki are having a batch made.

Did have some parts arrive back this morning though, had some smaller parts blasted:



Along with the cylinder heads:



The foot pegs and kickstarted have been blasted and then clear Cerakoted:





Clip on's, top yoke and rear hanger Cerakoted, along with a box of small parts:







As mentioned early on in this thread, the clip on's do seem to weigh alot. I don't have anything here to compare them to at the moment though.



I had told myself not to get too carried away with this but I have since ordered up a lot more titanium bolts and now that there is a delay on the crank coming through I may get the engine cases blasted as well and some more smaller bits off the bike.

Still hopefully plenty of time to get this done before next summer, although getting it registered is still a slight worry having not done this before. Quite fancy the Aprilia Factory track day and maybe the classic bikes 2 stroke one so if there are any hold ups on the road side I will still get out on it.

[MK3 Dan]

Marquezs Stabilisers said:

Most super has ethanol in it now, if you see E5 on the pump that means 5% ethanol. Only solution is either get the plastic tank Caswell lined (for which I'd send it to them having done it myself), or get a race spec alloy tank. If these were run at the TT someone somewhere will have made one.

Food for thought, thank you.

Thought I heard that the Esso stuff was still ethanol free but this might have changed recently.

Guess it's a decision if I risk it with Super, get the tank coated (although this always makes me nervous) or consider running a race fuel for the limited mileage I will be doing.

[stang65]

MK3 Dan said:

Thought I heard that the Esso stuff was still ethanol free but this might have changed recently.

It was ethanol free until September. How much ethanol is in it varies (like any fuel) and the 5% is the max that can be put in. I did see some numbers of which fuels had how much ethanol somewhere but forget where. If you're replacing the fuel lines I guess you'll be fine if you drain the tank after use which might not be an issue if you're using it for limited miles?

[Marquezs Stabilisers]

MK3 Dan said:

Food for thought, thank you.

Thought I heard that the Esso stuff was still ethanol free but this might have changed recently.

Guess it's a decision if I risk it with Super, get the tank coated (although this always makes me nervous) or consider running a race fuel for the limited mileage I will be doing.

Esso themselves saying on their website up to 5% ethanol. When I had a plastic Acerbis made tank as OE on my Ducati, I emailed basically all the fuel companies. Shell V-Power and Sainsbury's Super at the time both confirmed ethanol. BP Ultimate is also up to 5%.

[alvington89]

The clip on's will be weighted at the ends as this helps the handling.

[MK3 Dan]

Marquezs Stabilisers said:

Esso themselves saying on their website up to 5% ethanol. When I had a plastic Acerbis made tank as OE on my Ducati, I emailed basically all the fuel companies. Shell V-Power and Sainsbury's Super at the time both confirmed ethanol. BP Ultimate is also up to 5%.

Thanks for the info, I will have to make a decision nearer the time.

Not keen on draining the tank each time as whilst I wont be using it much, as in not doing lots of miles, I do want to use it ever few weeks through the summer if the weather allows.

[MK3 Dan]

alvington89 said:

The clip on's will be weighted at the ends as this helps the handling.

That is without the bar end weights though, that is the weight of a completely bare clip on?

Bar end weights are additional again!

[MK3 Dan]

Got the freshly coated top yoke and clip on's fitted last weekend.









Placed another order for a batch of titanium bolts tonight - dread to think how much I have spent on them!

Crankcases completely stripped and away for blasting, should have them back before the Christmas break so can at least get the bottom end together whilst waiting for the crank and barrels to land.

[Birky_41]

Attention to detail is spot on with this one! That will be like a show piece when you finish

Wish I had the patience to be that in detail with mine