Aprilia RS250 Project

[MK3 Dan]

Had some progress with the stickers today, in my opinion it transforms the looks!

[Mr Tidy]

Stunning.

[alvington89]

Looks great. Are you going to match the seat units graphics to the original scheme as well?
https://www.sargentsofsussex.co.uk/8995-aprilia-rs...

[MK3 Dan]

alvington89 said:

Looks great. Are you going to match the seat units graphics to the original scheme as well?
https://www.sargentsofsussex.co.uk/8995-aprilia-rs...

Thanks, yep that was this afternoons job so stickers are completed and the fairings are all going off for lacquer next week.

[carlo996]

Fabulous.

[Cabbage Patch]

Looks brilliant. Thanks for taking the time to post your progress.

[MK3 Dan]

Just realised I haven't updated this for a while!

It is now completely back together and has been MOT'd with no problems other than an advisory for the front headlight, which I knew about and is on the list to clean up at some point.

Got it insured, filled out all the paperwork and sent it to the DVLA last week, just 4-6 nervous weeks to wait and see if it is successful!

Only slight issue I have is the rev's hanging around 3000 rpm at idle but it will go down if put in gear and some slight load put on it. I have had the carbs apart and cleaned them all again for no change, along with replacing o-rings, needles etc and using some gasket sealant on the intake rubbers. Seems to be air leak but even checking around with brake cleaner it doesn't seem to change the running. Have taken it down a private road and it seems to ride ok but revs are capped for a bit whilst it goes through some running in.

[Steve Bass]

Fantastic result!! One of the nicest ever and a real credit to your work.
As for the idle rpm issue, also check the air solenoids as a sticky or leaking one will have the same effect. Try blocking the air tube from each of the solenoids and see if it changes the idle rpm....

[MK3 Dan]

Steve Bass said:

Fantastic result!! One of the nicest ever and a real credit to your work.
As for the idle rpm issue, also check the air solenoids as a sticky or leaking one will have the same effect. Try blocking the air tube from each of the solenoids and see if it changes the idle rpm....

Thanks Steve, really appreciate that.

That is a good call on the solenoids, must admit I haven't even thought about eliminating them. Will give that a go this weekend and see what happens!

[alvington89]

Just had a quick look back at what the bike was like when you started on the restoration and wow, there's no comparison to what it looks like now. You really have made a superb job of it as it looks mint now.

[cirian75]

Very well done, better than new.

[Marquezs Stabilisers]

That is utterly stunning, well done!

[MK3 Dan]

alvington89 said:

Just had a quick look back at what the bike was like when you started on the restoration and wow, there's no comparison to what it looks like now. You really have made a superb job of it as it looks mint now.

cirian75 said:

Very well done, better than new.

Marquezs Stabilisers said:

That is utterly stunning, well done!

Thanks all, really looking forward to getting it out on the road once the registration lands - if there are any problems then it will be a track day to give it a go!

Spent some time today trying to sort out the high idle issue, tried the solenoid's as Steve mentioned and despite thinking it was sorted when warming it up once warm it was the same. Some more looking around and checking throttle cable free play etc I noticed some excess movement in the junction box for the throttle, PV and oil pump cable. It seems to be worn and whilst I think the throttle is completely closed it is not telling the throttle position sensor that the throttle is completely shut (tested this with a multi meter, 1v at closed 1.2v when it is closed but TPS isn't) - I wonder if this effects the ignition timing. The second you gently push the TPS with screwdriver shut the revs drop to normal. I tried shimming the box to remove the free play but this made no difference.



Going to contact Sean at TTW to see if he has any options on a replacement TPS. Sat here thinking about it as I type I also want to check my oil pump cable and setting to make sure that it isnt holding anything slightly open.

I am at least a little releaved that it is not something too major and at least now I know the problem I can set about fixing it!

[MK3 Dan]

And a short run up video for 2 stroke noises!

https://youtube.com/shorts/it0ZC_zjxEM?si=LRM28YqV...

Edit for failing to embed! Hopefully the link works.

[Steve Bass]

MK3 Dan said:

alvington89 said:

Just had a quick look back at what the bike was like when you started on the restoration and wow, there's no comparison to what it looks like now. You really have made a superb job of it as it looks mint now.

cirian75 said:

Very well done, better than new.

Marquezs Stabilisers said:

That is utterly stunning, well done!

Thanks all, really looking forward to getting it out on the road once the registration lands - if there are any problems then it will be a track day to give it a go!

Spent some time today trying to sort out the high idle issue, tried the solenoid's as Steve mentioned and despite thinking it was sorted when warming it up once warm it was the same. Some more looking around and checking throttle cable free play etc I noticed some excess movement in the junction box for the throttle, PV and oil pump cable. It seems to be worn and whilst I think the throttle is completely closed it is not telling the throttle position sensor that the throttle is completely shut (tested this with a multi meter, 1v at closed 1.2v when it is closed but TPS isn't) - I wonder if this effects the ignition timing. The second you gently push the TPS with screwdriver shut the revs drop to normal. I tried shimming the box to remove the free play but this made no difference.



Going to contact Sean at TTW to see if he has any options on a replacement TPS. Sat here thinking about it as I type I also want to check my oil pump cable and setting to make sure that it isnt holding anything slightly open.

I am at least a little releaved that it is not something too major and at least now I know the problem I can set about fixing it!

In short, yes. The ignition tables at low tps have fairly big steps. If the tps isn't closing properly then the ecu will send the appropriate ignition timing based on the open values.
Those junction boxes are a PITA and I'm not sure they're even available any more. You might have to adjust it as best you can. Alternatively, the zeeltronic allows you to establish any voltage as a closed condition as well as a host of other benefits. But probably close to a grand including the wiring interface.
Also check the sync with the throttle slides at the marked line and the oil pump position. It won't be massively out either way but the tps may be "sloppy" regardless which is difficult to fix without a brand new junction box

Edited by Steve Bass on Sunday 7th July 23:02

[Mr. Potato Head]

Really enjoyed watching this thread. Had a silver 125, always wanted but never had a 250.

Lovely bike