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Messing with my Aprilia Cup

Discussion in '2-Stroke Machines' started by Mike Fennell, Apr 19, 2024.

  1. Mike Fennell

    Mike Fennell Never Was

    If anyone cares, I'll post some updates as I go through the $3800 Cup bike.

    Put it on the lift and started tearing into it. I can't put spools on the swingarm because a bolt is broken off on one side. It has a sidestand that I propped up to level, then I secured the bike with a tie down.


    Two of the subframe mounts are stripped and there's a bolt/nut combo instead.

    The coolant overflow is all rashed up. The level line disintegrated when I touched it. I seem to be able to add a few oz of coolant every time I open the cap, which is slightly concerning.


    I thought this was an interesting detail. Adding oil requires unbolting this clip.


    Speaking of oil, the tank was completely empty. There was a little in the line. It smoked when running so I think the pump is working. I'll be sure to check.

    I ran my borescope into the cylinders (the plug wire cap came off the wire on the vertical cylinder). The shape/angle of the heads make it hard to see everything. It's not a horror show but I think I see a bit of pitting on the vertical. I'll pull the pics off my scope.

    No air filter. The air intakes clamps weren't tightened and one intake wasn't actually on its carb. The carb drain tubes were pointing up so I couldn't drain the bowls.

    Date codes on the tires are from '04 and '05. My first thought was old tires thrown on just to roll it except the front brakes and axle are wired. Guessing it's been 15 years since the bike was on track.

    I had thought I'd just whip through the bike and drag it to the track but it's probably smart to go in a little deeper first.
  2. BlueR32

    BlueR32 Well-Known Member

    With a 2-stroke I'd definitely recommend going through it before tracking. Concerning that oil tank was empty, perhaps was run on premix?
    Mike Fennell likes this.
  3. Mike Fennell

    Mike Fennell Never Was

    The seller told me he ran the pump and it's still there. The cynic in me wonders if something is wrong with the pump and there's pre-mix in there now.
  4. motion

    motion Nihilistic Member

    Mike Fennell likes this.
  5. Mike Fennell

    Mike Fennell Never Was

    Found this crack last night. Nice of someone to stop drill it but you'd think they might have used a smaller bit.


    Spent 20 minutes gradually drilling out the broken bolt in the swingarm for the spool. It's now filled with the remains of an EZ out. The bitch of it was I spend a minute thinking maybe I should just drill it all the way out and put a timesert in there. "I'll just give it a easy turn - if it's really stuck I'll drill it out".
  6. freedomgli

    freedomgli Well-Known Member

    So it seems it was kind of a basket case after all. C’est la vie. It’ll be a good bike once you’ve gone through all the age related stuff and typical track bike stuff. The only question is how far will you have to go to have confidence in everything. Minimum all new fluids, new coolant hoses, clean the carbs (and likely new intake boots), lubricate everything, replace missing/ damaged/ non-standard items that are questionable, tires, brake hoses, repair subframe cracks, new sprockets and chain.

    I’m still hoping to do the Cougar Red power valves, pulleys, RGV250 PV cables and Zeeltronic on mine before tracking it again. It’s not cheap but rather insurance against even more costly engine repairs or heaven forbid a crash/ injury.
  7. Mike Fennell

    Mike Fennell Never Was

    I'm falling back on 'priced appropriately'. It does appear to be straight and I would have done most of that stuff anyway. I found a ding in the pipe side of the swingarm from a footpeg and the non-pipe side looks like it was dragged through a gravel quarry but I haven't found any evidence of a serious yard sale.

    I approve this message.
    freedomgli likes this.
  8. BrentA

    BrentA Very expensive.

    Following for updates and more pics. Good luck!
    Mike Fennell likes this.
  9. SuddenBraking

    SuddenBraking The Iron Price


    And if you need a second set of hands, I’m in Bucks County.
    Mike Fennell likes this.
  10. Mike Fennell

    Mike Fennell Never Was

    With the overwhelming demand, I'll try to keep it up. :D

    I solved the cold radiator mystery. No coolant.


    I'm assuming (hoping?) some previous numpty didn't bother to open the radiator vent when filling it.

    I pulled out my future 848 track bike to cleanse my palette so to speak. This bike is spotless. Ran it for a bit and rode up/down the street before draining the oil to send to Blackstone. It has an interesting back story. This bike has never seen the street. Way back in 2009, Dennis Espinosa was racing at NJMP and completely yard sale'd his 848. Ducati was there with bikes for show or demo or something. He bought a new 848 directly from them, prepped it, and raced the following day. RRW had a video but it's long gone: https://www.roadracingworld.com/new...es-from-showroom-stock-to-racebike-overnight/

    BrentA, Phl218 and SuddenBraking like this.
  11. Mike Fennell

    Mike Fennell Never Was

    Pulled the cradle off yesterday. The bolts holding the coils were finger tight. All 4 of them.


    I was happy that it wasn't under any tension and fits perfectly.


    This also made me happy. The throttle box thing (it allows the PV controller to pull the the oil pump cable) is spotless inside. The 1895km on the dash might even be accurate. 1895km of abuse, then years of sitting around ignored, granted.


    Hope to drop the cradle off with our local artisanal welder (weird dude but creates things of beauty out of a mess of a shop) for some love. Found more cracks once I had it off the bike.

    I guess I'll drop the engine and see what I can screw up.
  12. Mike Fennell

    Mike Fennell Never Was

    Dropped the cradle off at the fabricator last week. It will be done when it's done.

    Managed to get the broken extractor out of the spool mount with a carbide drill bit, cutting oil, and some patience. I'm not sure what I'm going to do. The other side is already drilled out and has some threads in it. Maybe for a timesert? Not really high on my priority list.


    Continuing to enjoy the complete lack of detail shown by whoever threw the bike together last. Idle and air solenoid bracket bolts weren't even spun in all the way and the other fuel line clamp was loose too. Ditto the clutch actuator lever. Given the pile of parts I have, including good looking cylinders & a full gasket kit, my theory is that someone in the past was planning to rebuild the other engine, lost interest, found something (it honestly looks like the engine was sitting outside) and had his drunk buddy cobble it together enough to get it running.

    Oh, no springs on the expansion chambers. They just slip-fit into the mounts, right? I guess they're rusted in place.

    Everything is disconnected and the engine is ready to come out. How heavy are these things?
    BrentA likes this.
  13. Mike Fennell

    Mike Fennell Never Was

    Engine out last night. Gearbox oil was really dark but no metal on the plug. Throttle cable has a lot of friction.


    Some quick detailer and a rag. Pretty happy with the parts of the frame that haven't been thrown down the road.


    Pulled the heads this morning. I don't know anything about anything but it's not a horror show. I think this is pretty good.

    Top cylinder.


    Front cylinder. The specs that look like rust are just drops of coolant.


    Front piston.


    Some crap in the coolant.


    Not sure what to do next. Fresh gaskets and send it? Fresh pistons with my spare cylinders (which look better, IIRC)?

    I finally got a ultrasonic cleaner and expect to get a lot of use out of it in the near future.

    Dropping off the neighbor's daughter after carpool, I couldn't help but notice the industrial oven in his trailer. He came walking over. "Powder coating?" "Yep. First I'm going to replace the knob with a proper PID controller." He gets up to the best shit when he's out of work. Looks like it will easily fit 17" motorcycle wheels.
    Last edited: May 3, 2024
    Phl218 likes this.
  14. Mike Fennell

    Mike Fennell Never Was

    Cylinders off. Coolant from the top cylinder looked tasty.


    Nothing too scary about the piston.


    No vertical play in the piston/rod assemblies.

    Thought I had a bad throttle cable so I pulled it off this morning. It turned out that the bar itself was just nasty with built up grime. Some clean up and a little lithium grease and it's smooth.

    Need to start figuring out what I need to order from TTW. I have a bunch of base gaskets that came with my other MK1 to inventory first.

    Inventoried some of the OEM Aprilia bits last night. For some reason, I have all four lower fork mount bolts brand new in bags. Those are possibly the only fasteners on the bike that aren't corroded. There was a bag marked with the part number for the pinch bolts too but the head is too small. Found new Suzuki reed valves in the pile. Need to see what base gaskets I have on hand from my MK1 then get an order together with TTW.

    Thinking, at a minimum:
    - Vertex 2 ring pistons
    - Cougar one piece power valves
    - Silicone hose kit (TTW carries JS Performance)
    - Engine seal kit, so I have it on hand

    - fork seals 'n shit?
    - Cylinder heads/nuts that don't look like they came out of the garbage

    Other things:
    - caliper rebuild kits
    - rear master rebuild kit
    - brake lines

    Ordered not-Mitutoyo (Fowler) bore gauge and micrometers yesterday to see what I actually have.
    freedomgli likes this.
  15. Mike Fennell

    Mike Fennell Never Was

    Still figuring out the bore gauge and micrometer but my good spare cylinders are indeed really good. I've never used a bore gauge. It's fascinating to see the difference in wear (about the width of a strand of hair) when in line with the thrust side vs 90 degrees out. The good cylinders are essentially zero wear.
    freedomgli likes this.
  16. Mike Fennell

    Mike Fennell Never Was

    Gradual disassembly continues. Possibly nice surprise of a Hyperco spring. They can't be bothered to put rate anywhere you can see but I have to take it off to replace the bump stop anyway.


    The cylinders I found in the transit case:


    I haven't actually spent any money on parts yet (dragging my feet for no good reason) but it looks like I'm going to come in at around $2k including tires but not including tools ($250 or so) because tools don't count. Call it $6k all-in for a mechanically freshened track bike with some patina.

    Just had a scare. Texted the fabricator to see what was up. "What's this from? It has too many problems - you need to find another one." "Oh shit, they are impossible to find. It's from an Aprilia RS250". "Oh, sorry. I have parts from 3 different bikes here. Welded your frame up. It moved a lot." :D

    I'll finish stripping the frame (except swingarm - waiting on tool from UK) and bring it with me next week so we can align it.
  17. SpeedWerks Racing

    SpeedWerks Racing Well-Known Member

    They engrave the spring weight on the top (flat part)
    Chris' cradle here has like 10 cracks in it, with no good ones around, we might have to just make a few...
    Mike Fennell likes this.
  18. Mike Fennell

    Mike Fennell Never Was

    I can get a ballpark number from Matt for 10 (?) when I stop by to pick up my cradle.

    Daughter: "OMG, where did the motorcycle go?"
    *sweeping gesture with arm* "Everywhere."


    I thought to loosen the caliper pinch bolts (for fresh seals later) before pulling the forks. Managed to get 6 of 8 loose so I only have to drill 2.

    I should order some parts.
  19. Mike Fennell

    Mike Fennell Never Was

    Some parts ordered from TTW. 1 piece powervalves, fork rebuild parts (not sure I'm actually going to use them but handy to have on hand), cylinder head nuts that don't look like they were fished out of the garbage, coolant hoses, and a seal kit. Hope to pick up and fit the engine cradle tomorrow.

    My friends were busting my balls about not splitting the cases but I feel like I'm already getting a bit ahead of my skis on this one.
  20. Chris Mann

    Chris Mann Well-Known Member

    The "Chris" SpeedWerks is referring to is me, finally found a cradle but it has a small crack that I will get repaired. Hopefully Steve and his team will be finishing up my bike real soon, has been a real chore finding parts. Bike had a 300 kit on it but melted the rear piston so taking it all back to stock. Will have parts for a 300 kit if your interested.
    Mike Fennell likes this.

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