Jump to content

Aprilia RS257


wazrs257
 Share

Recommended Posts

I've seen people using these on drag bikes where they need high fuel flow http://www.toolstation.com/shop/p76890, much cheaper than a pingel.

Also once you've cleaned the tank out it shouldn't really need a fuel filter, but if you get a disposable paper one for a car that'll flow enough.

Thats a possibility, just trying to work out how to 'plumb' it in! :thumbsup:

Another possibility could be this:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...e=STRK:MEWAX:IT

If it flows enough for a big KTM/Husaberg, surely it should be enough for my needs?

Link to comment
Share on other sites

Result on the MOT Waz :thumbsup: (i can legitimately say it this time)

Cheers. :eusa_think: Just need to get it running right now. I was gutted at not making it to the Shoulder of mutton yesterday, but it seemed pointless putting miles on a race engine & risking seizing it, just for the sake of it. Am waiting for an in line fuel filter to arrive so I can try it out with the unrestictive fuel flow.

:thumbsup:

Link to comment
Share on other sites

i've been meaning to ask whats that engine like . my old cr500 was way too vibey . when does the power come in and out

Hi GGC. The engine is solidly mounted, so yes, it does vibrate like a b@stard! There is a balance shaft fitted, so I would hate to think what it would be like without it. I have to check it over after each ride to see whats about to fall off, the left hand footpeg is a favorite at the moment for some reason!

The exhaust has been designed to peak at 10'250 rpm, so the engine should be producing high 50's BHP. Unfortunatley, due to the way its running at the moment (& a slightly dodgy Scitsu tacho) I cant really comment on midrange/flexability.

:eusa_think:

Link to comment
Share on other sites

I fitted an in line fuel filter today, so was able to test the modified fuel system. Its now happy to rev out through the gears, with no feeling of 'holding back'. Unfortunatley it hasn't helped the part throttle running, in the words of Roy Walker, 'Its good, but its not right'! Im starting to think that its just a symptom of a highly tuned 250 single stroker! It starts fine & low down is ok. Its just that you have to have the throttle WIDE open to get it to pull into the power band, at which point it goes mental! There seems to be no fine control at all.

Will get it taxed for the start of next month & try a few longer rides to get used to it. I have to admit that its been a few years since my LC days, so I may have just been spoiled by grunty GSXR11's!

:icon_puke_r:

Link to comment
Share on other sites

doesn't take long away from a 2t to forget about constant gear changes chasing the power . last 4 stroke was a tl so real chalk and chease . got any vids of it running then mate .

Link to comment
Share on other sites

doesn't take long away from a 2t to forget about constant gear changes chasing the power . last 4 stroke was a tl so real chalk and chease . got any vids of it running then mate .

I've got a short video on my phone that was taken the first time I fired it up after the pipe was made. I've managed to transfer it to Flickr, but cant seem to work out how to post it! any ideas?

Link to comment
Share on other sites

I've checked the carb over today & found that the needle is well worn where it goes through the slide, and its probably safe to assume that the slide is worn too. Due to this, I've decided to replace all the parts of the carb that can possibly wear, including needle, emulsion tube, slide & cut off valve. Probably going to be a big bill from Dellorto, but its the only way to get a reliable base setting. The good news is, whilst rooting around in the garage I came across a tin marked 'Rotax jets', containing a few needles & a dozen or so main jets, left over from my kart racing days.

:eusa_think:

Link to comment
Share on other sites

For sale I'm afraid...again...keep changing my mind...always wanted an RS125 though

Want to get my CRF supermoto rebuilt before the end of summer so need funds.

Link to comment
Share on other sites

For sale I'm afraid...again...keep changing my mind...always wanted an RS125 though

Want to get my CRF supermoto rebuilt before the end of summer so need funds.

I know what you mean, I sold a Toyota Celica GT4 to get the cash for the pipe on my bike. Projects feed projects!

:eusa_dance:

Link to comment
Share on other sites

Not at the moment mate, maybe in the winter when i'm bored again.

Waz - what gt4 did you have, hoping to get a st205 when(if) I sell my nc30

Link to comment
Share on other sites

Not at the moment mate, maybe in the winter when i'm bored again.

Waz - what gt4 did you have, hoping to get a st205 when(if) I sell my nc30

I had a jap import ST185, a lovely car to drive but about 20mpg on a run, maybe that was just down to how I drove it though! The insurance was high aswell, I'm not some young whipper snapper but it was still costing over £500 a year. In the end I decided that I couldn't afford to run the GT4 & my bikes, so the Toyota went & got replaced by a chavy corsa! Will be bringing my GSXR7/11 out of hibernation aswell soon, so plenty of toys to choose from still!

:)

Plus the fact that the roof on the GT4 wasn't high enough to get my hair in!!

Edited by wazrs257
Link to comment
Share on other sites

7/11 - What make/model, slingy or slabby? Fightered?

I've been saving for a new (2nd) car for a while (which is why I'm so skint I expect) as I spend much of my free time driving with my wife and daughter so I'm looking at something to make that a bit more fun - looked at Civic Type R's, Integra's, GT4's and Seat Leon Cupra's etc but not seen anything in budget that catches my eye yet. more saving and waiting to sell the NC30 needed

Link to comment
Share on other sites

Just wondering where you sourced the engine from?

My brother found the engine for me on a kart forum. The guy was selling it to finance the purchase of a Bultaco engine for classic karting. Previous to this, I put a wanted ad on a kart forum, but that didn't turn up much. My next course of action was going to be putting up a for sale ad at a couple of local kart clubs, but then this one turned up. I got a 'spare' top end with it that requires welding/re-plate, So will get this done some time in the future.

Link to comment
Share on other sites

I've priced up all the parts from Dellorto to sort my carb out & was shocked to say the least. To replace EVERYTHING is only £40 cheaper than the price of a brand new, jetted to my spec VHSB39 carb!

VHSB39

My current carb is 38mm, so is undersize to start with, probably to increase midrange for short curcuits. It has also had an adapter 'bodged' on where the air filter clamps on. Im starting to think a new carb is the way to forward.

:eusa_whistle:

Link to comment
Share on other sites

not sure who you tried but i tend to get my carb bits from allens

http://www.allensperformance.co.uk

I went straight to the main Dellorto importers ( http://www.dellorto.co.uk ), their website is very informative. Will check out the Allens website before i commit to anything though.

As I said, my carb is old/worn, so I priced up ALL the parts except the main body. A new carb makes more sense due to the fact that the main body has been improved/redesigned over the years. I think my carb is about 10-12 years old, so plenty of hard racing miles under its belt!

Edited by wazrs257
Link to comment
Share on other sites

Bit of an update!

I was a bit reluctant to spend £200 (+vat & carriage) on a new carb before I'd made sure that this was indeed the problem, so it stripped the old carb & started measuring. The needle, although worn where it goes through the slide, appeared to have very little wear on the taper. This was confirmed at work when I set it up on a shadow-graph, the taper was a fairly constant 1.5 degrees & the diameters were correct within .01mm. Next I measured the emulsion tube. The standard emulsion tube is a DQ264 (2.64mm I/D), using calibrated measuring wires I found the I/D to be 2.71mm. This is the equivlalent of going up 7 sizes of emulsion tube!! The largest size they supply is a 276. The other jets were found to be correct, so the finger of guilt was firmly pointing at the emulsion tube.

I ordered a new emulsion tube from Eurocarb Ltd last night & it turned up today. As soon as I fired the bike up, just blipping the throttle, I could feel how much crisper it was. I warmed it up to about 40-45 degrees, then set off up the road. Initially I was a bit dissapointed because it was still hesitating, so I pulled over & let it warm up to just over 50 degrees. The difference was amazing, it pulled cleanly with only a slight hesitation at about 7'000rpm. The powerband proper seems to start at 8'000rpm & it would happily run to 11k if I'd let it! As the temp dropped down below 45-50 degrees it started getting a bit wooly again, so my next purchase will be a thermostat.

Sorry for the long winded explanation, but I came over all excited!

:icon_bounce:

Link to comment
Share on other sites

So how much did this save you?

The emulsion tube (and a couple of spare needle circlips) was just under £23 including vat and carriage. Plenty left in this months budget for a thermostat and a steering damper now, it needs one badly!!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...