The Hermes Project (Cagiva Raptor 125)

[Calum]

This little machine has been a little work horse for the last 5 years and the engine was due a refresh when my brother bought it originally. My brother is also hard on bikes, having previously worn out the rear wheel due to a worn wheel bearing...

This weekend saw two solid days of top engine refresh...

So this is how the bike sat for two days as I worked solid to strip it down for a refresh.

A whole host of goodies from PJME

Not all of this is being fitted in this current build but the list of parts are:

• New Clutch Plates
• New Gear Oil
• Genuine Cagiva Barrel
  • 60433 - Fitted
  • 73037 - Future project
• Polished head
  • 200C - Fitted
  • 200H - Future project
• Italkit Pneumatic Valve - Will be mated to the 73037 Barrel - Future Project
• Vertex Twin Ring Domed Piston Standard Size
• New Silver Coated Little End Bearing
• New Athena Gaskets
• VForce4 Reed Block
• New Genuine Inlet Manifold
• Dellorto VHST Flat Slide Carburettor - Replaces the roundslide PHBH
• New Plated Barrel

Poeton charged £260 for the replating of the barrel, due to it previously being scored. Recommended Grade A piston replaced. The piston ring end gap toleraces are measured.

Titanium studs fitted along with Titanium domed nuts

New VForce4 Reed block + Genuine Inlet Manfold fixed with titanium bolts torqued to spec.

Once installed the squish was measured and kept to as close as standard as possible.

Good sealing through the rings, although I expect this to drop once it's been run in.

Was making 140 PSI prior to the rebuild so this is a healthy number to be making. Although, as said, I expect this to drop after the break in period down to 150-170.

This rebuild was to replace the Mitaka barrel and the scored piston/barrel that was previously fitted. Whilst the works were underway, I cleaned all the powervalve assembly, which was heavily coked up, as well as all anscillaries and replaced all fluids.

What I didn't appreciate, was that Cagiva made many barrels for the Mito over the years and the one I purchased was the very early barrel off the Freccia. This is probably the worst barrel I could have bought and may actually have worsened the performance of the engine.

It may improve it slightly in the ways I use the bike. The exhaust is slightly smaller and the transfers are also smaller with fewer numbers. This could result in greater pressures through the transfers and improved mid-range performance. Which the Raptor could benefit from.

I have sourced the better setup for the mito and I have acquired a spare bottom end that I will rebuild and fit this to.

I also saw that Italkit were offering a Pneumatic valve for this engine too. I bought this as a bit of a novelty, unfortunately it's the non-adjustable one and I hear it opens at the wrong time. But electronics don't last forever and at least I have a replacement powervalve system in the event mine fails.

[Calum]

Swapped out the PHBH 28mm roundslide for a VHST Flat Slide and jetted to suit.

Despite, technically being an inferior barrel, performance in the midrange definitely has jumped up. Haven't yet pinned it to check top end but I suspect to lose a little HP up top due to the port dynamics. So far so good though... I will upload a short short short of me bleeding the oil pump just for a sound check.

https://youtube.com/shorts/wpYmsaPoUfw?feature=share

[Calum]

Savage!

I was just collecting all the spare bits from the rebuild, I like to keep parts 'in case of an emergency'...

https://youtube.com/shorts/0KlaU_adlWg?si=eHzrxklmGSn4Bo2L

But wow! Top of the piston was cracked going through the ring lands and to the gudgeon. The thing was a literal ticking time bomb!

I have known that the cylinder was in need of a refresh for quite some time, but I didn't appreciate the extremity of the situation. I have been using the bike lightly this year and it hasn't been ridden prior to that for at least two years, if not more.

But yeah that's really awful, never seen a piston crack before.

[SpookDog]

@Calum

What make?…

The casting on the other side (bottom of gudgeon pin hole) doesn’t look too clever either!…

[Calum]

@SpookDog I don't know, it was all fitted to the bike way back when.

I'll assume it was a Mitaka piston as it was mated to a Mitaka barrel. I suspect the previous owner replaced the genuine barrel with the Mitaka Barrel/Piston combo.

[ZKJE101]

@Calum Hi mate. Great little bike you have here... I just picked up a 2006 Raptor 125 from a friend of mine for a steal which is in great condition to be fair but it will be my winter project for a full nut and bolt rebuild! Just wondering if you would be able to answer a few questions if you have the time??

[Calum]

Sure you can, just post a thread up and I will probably answer it.

Failing that, the best place is probably the cagivamito blogspot.

http://cagivamitoevo125.blogspot.com/?m=1

[ZKJE101]

Cheers mate will post a thread up myself! maybe a similar style rebuild thread...

[Calum]

So the little Cagiva has developed some minor engine issues. Suspect crank seals may be going bad. Bike won't idle now and if left to idle manually struggles to rev cleanly. I have a spare bottom end I got earlier in the year with the top barrel to put on it and I will endeavour to build that as a drop on replacement. For the moment however it will just have to make do...

That said, been after one of these all year and yesterday TYGA Performance delivered on their promise

Again an immediate difference in performance, pick up in the midrange is excellent and felt a tad stronger up top to boot...

What you have to appreciate about these bikes is that they were already rapid and the gains here are going to be minimal. I like Zeeltronic as a brand and like what they make. Pleased to add another one to my collection.

[ZKJE101]

Looks like a fun little upgrade! Even better pickup in midrange that would make these little bikes even better

[ZKJE101]

Just wondering if you would be willing to knock up another set of the paddock stand spacers for some ££? I have made something similar on AutoCAD but those are 3D printed with carbon fibre reinforced PETG, but metal would be ideal for peace of mind!!

[Calum]

@ZKJE101 Hi bud,

Not sure if you're still interested in these? Access to my lathe has been removed for the moment, so I've taken one off of my Cagiva and gave it to an engineering firm to knock up a set for you if you would like them?

Unfortunately, these are not CNC'd and he said it'll take 2 hours to make. Like mine, it'll be turned by hand. I'm having another set made for myself and asked to make a set for you as well.

If you're interested let me know, engineering firms are shut for the holidays now, so won't see anything until next year.

Cheers,

Calum

[ZKJE101]

@Calum

Hello mate. Sorry for the radio silence, my project has been on pause the last few months due to other commitments. I’m defo still open to paying for a set of bobbin spacers if you are still up for it?

[Calum]

@ZKJE101 Sorry bud, a move was necessitated and access to the lathe has gone

I can send you the CAD files and you can get someone to knock them up for you if that helps?

I use a chap called Quantum Solutions who seem to fit the bill nicely.

Hell, they're not structural I could just 3D print you up a set if it helps.

[ZKJE101]

@Calum no worries mate. I would take a cad file if you wouldn’t mind sharing will likely send them off to a local machinist. I have a 3d printer as well so could try the cad file on there!