1990 VRP Mugen 125 - rebuilt

This upcoming 20th september there is a race for the italian vintage series (Campionato Italiano motocross epoca) in Montevarcchi / Tuscany. Exactly 25 years ago i rode the qualifications of the 1990 125cc worldchampionships on that particular track using my VRP bike.

So, wouldn't it be nice to ride that track again 25 years later, basically on the same bike? BUT to be eligible to participate in that italian championship your bike has to be max. 1989. This is possible with my VRP chassis since it was made in '89 ('90/'91 were unchanged).

So all i need is to convert my 90/91 VRP back to a '89:
-swap out the USD forks and put in some old-school regular forks
-different gas tank
-different rear subframe/airbox
-different saddle
-all new plastics
-engine with ATAC exhaust system rather than the HPP engine
-different exhaust

At least the bodywork is now changed.....enjoy:

It all started with the installation of the sweet suframe/airbox combo:


Since i was able to buy it off Ebay it really needed to be refurbished. And as soon as we mounted it it was clear there was some need to straighten it in the rear...my dad was on hand with a gentle hand By the way - doing this rebuild was like a flashback for the two of us. After about 20 years we were both spending evenings down in the garage wrenching on our old bike just like in the past. Too cool!


'89 VRP gas tank with air channels that direct air from behind the numberplate directly into the airbox (RAM-air):


The Dremel was always in use when trying to fit new plastics on....each and every part needed some custom tuning:


Fitting of just one side numberplate: approx. 2 hours !!








Plastics in place:


Since the gas tank had those funnels for the air you also need a ventilated front numberplate. So we went to work and cut one of my '94 numbeplates in half with still the No. 1 on it of my year als reigning 125cc swiss champion


Cutting plate and numbers:




Finished front numberplate (you wouldn't want to know how many hours it took...):


I'll come to an end...here she is:




Right side up forks tuned by italian Poletti Suspension. Factory-look !!


What an ugly number i got: 137 - damn!


However i had to put my signature No. 8 somewhere




Here's the mentioned air channels in the gas tank right behind the numberplate:


Just some aluminium...some 8 years before Honda offered the 1st aluminium production frame ('97 CR 250):


For now it still has the 1990 Mugen HPP engine in it. Just this weekend i'll start transplanting the heart...and mount a ATAC cylinder which then also requires a different exhaust...



Just a sidenote.
Isn't it cool that the same, 25 year old engine is still a capable weapon today? I mount my original 1990 Mugen of back in the day on my CR 125 AF below. That thing is a real rocketship and still faster than todays offerings (KTM included!):

My actual weapon: CR 125 AF with CRF chassis and '90 Mugen HPP engine, verified 88 kilos / 194 lbs weight (= lower weight limit!)

This is a much better picture of your bike with the two of us


...and at the first round of this years italian vintage championships at Malpensa. I got to ride his '87 Mugen Honda (left) while he was riding the full VRP rocketship Just like my competition in the past you feel at a disadvantage when you stand next to such a bike...


Isn't it funny that we two met because of our passion for VRP and Mugen. I'm from Zurich/Switzerland while he is from Sicily/Italy. We are the same age (1967), just two days apart (his birthday was on august 28th, mine is just now ), and we both have No. 8 on our bikes. Incredible !!

After the tuned '89 ATAC cylinder showed up with bad nicasil i had to send it in to get it replated. But i doubt it gets back in time for the Vintage race i'll participate on 19/20th september.

So yesterday i went for a 1st testride still with the '90 Mugen in place.

I enjoyed the ride and was amazed at how well it can be ridden. 26 years old and still a good bike out on the track. I was doubting those forks since just looking at those spaghettis i feared they would twist under load...but not so. They would actually work pretty well. I had them bottom out though so i think i'll raise the oil level some. The rear Öhlins however worked really great. I wouldn't mind race this rear end on my actual racebike. Amazing. But there's still some work left: the brakes don't perform as they should and also the engine lacked any bottom end...i think there's an issue with the exhaust valve. I still have about 1 week to get that straight. But riding my bike was really a nice experience. I also had a good smile when some guys would show up in the pits telling me i was riding very fast and that the bike sounded agressive....when they realized it was actually a vintage bike they had a hard time to believe it. When i told them about the bike in detail they remained with their mouth open ...

Don't laugh - Since it took so long to build the bike and i had all plastics new and new graphics as well i covered my bike with tape just to avoid any possible scratches before the actual event:


So after the wash and after removing all the ugly tape it looked a little better:

The video is actually from this past saturday. I waited already too long to get my tuned '89 cylinder back but i eventually had to do the roll-out still with the '90 HPP Mugen in place.

Just have a look at how the '89 ATAC cylinder looked like when i got it back from my german tuner....i told him he should take care of replating if needed. He obviously didn't do so. Anyway - as soon as i got it i immediately sent it to Holland to have it plated but it might be too late for the upcoming race next weekend. Too bad. Interesting though the tuning that was done: look at the additional port just above the exhaust bridge! That small exhaust port was added and to have it work it also needed a custom-made ATAC valve. This tuning was successfully used in the worldchampionships back in the day.

I would have had everything ready to go:
Tuned '89 cylinder, o-ring converted head, aluminium ATAC cover


Check the additional port in the middle and also the custom exhaust valve:


BUT take a look at the Nikasil - ouch !!


Anyway - i really enjoyed riding my old racebike after so much time. I expected the forks to be flexy like wet Spaghettis but not so. They perform actually quite well. I still need to add some more oil to them as they would bottom out a little too easy but overall they do great. The rear Öhlins shock was unused for at least 18 years. I really didn't expect it to work at all but it seems really ok. I wouldn't want to know how the oil looks inside there but anyway - so far it works. The biggest problem though were the brakes. I installed a new rotor in the front paired to new AP pads which are a tad more powerful than the stock Honda pads. This can only be helpful with the small diameter rotor these bikes had back in the day. BUT the real issue was that both calipers , front and rear (!!), wouldn't let the brakes out when hot. So within 2 laps you had the brakes basically dragging front and rear which really gave the engine a hard time on those steep uphills. At first i wasn't even able to shift into 3rd gear! I didn't realize that it was the brakes that caused the issue but rather thought the old engine might have blown seals or the carburetion beeing off or whatever. It just had a massive bog when shifting into 3rd. I also checked the exhaust valve for correct operation only to discover that it was actually the brakes dragging heavily. I solved the front brake issue by replacing the whole brake with the one off my '98 bike i had in my trailer. So in the video the bike was actually performing quite well considering the rear brake was still dragging quite heavily.

So this week i'll have to get the brake issue sorted out. But i guess the ATAC cylinder might arrive too late now. I would have to get another testride to have the engine and carburetion sorted out but time is really running out now. I might have to ask for a permission if they let me ride with the actual HPP engine instead. I hope this is possible. I'm not looking for any advantage here but just ran out of time. I spent a fortune in the cylinder, tuning, small parts and custom Messico exhaust. What a shame

Custom '89 Messico exhaust waiting to be used...

I'm not racing at Farleigh Castle! Farleigh was this weekend already and is over by now....I will participate in a round of the italian Vintage championships in Montevarcchi (former GP track) on 19./20. september. For me this will be a special event since it's 25 years that i could participate in the 125cc worldchampionships also down there on that exact same track with almost the exact same bike (same chassis but with the '90/'91 specs it had before).

No - there is no way i'm going to just stick a piston in there and wait for disaster. This is going to happen, more sooner than later. I won't do all the wrenching, expenses and finally also an 8 hour drive down to Italy just to have my engine let go. If i do it i'll do it right. And as mentioned i'd need some riding as well to find a good setup.

This past weekend i finally had that vintage race of the italian championships.


Campionato Italiano Motocross d'Epoca in Montevarchi / Italy (former GP track)


It was a busy 2-3 months converting my already mounted 90/91 VRP back to a race-ready '89. It turned out i basically had to start from scratch and had to work on almost every angle and every single bolt on the bike. But the result was well worth it. The atmosphere at the race was just too cool. There is that laid back mode, high fun factor, not a single bad word, no agressiveness, no anger ...just pure joy and friendship among all participants. High respect between each and everyone and everyone was helpful when you had a problem. Although i speak italian real good i was not familiar with how things went from tech inspection to sign-up...everything was new so i always had to ask and always got helped out.


In the end though we still raced our bikes and it was pure joy this time. I was not just cruising along but really riding hard. The bike was working almost perfect. Too bad i just did a few spins on a very small track back at home so i wasn't able to set it up properly for the demands of a GP track with higher speeds and bigger jumps, steep up- & downhills....the forks ended up beeing too soft again and i added even more oil ( i already added twice back home).


The moment i unloaded my bike there were guys coming from everywhere to have a look at my VRP:



I was really surprised to get 3rd in timed practice. Last time i competed in this championship aboard a lent bike from my sicilian friend ( a '87 Mugen Honda) i lost about 8 seconds a lap...i was now down to just 3 seconds which speaks volumes on the performance of my bike:




In the races later on i got 5th both times. I just had a hard time keeping my pace as the still too soft forks would dve too much and make for a nervous front end which really tired me out big time. But i still got 4th overall and since they offered trophies up to 5th i also got one [ ]




Out on track:



Early on right behind the leaders (behind a real works Cagiva). No. 19 in the back there is Frank Philippaerts, father of former worldchampion David Philippaerts.




In the end i beat my sicilian "twin-brother":





Me and my sicilian friend Gherardo who is the only one having another complete VRP Mugen 125:




2x VRP Mugen Honda. There is a better chance to have several worksbikes next to each other than having two VRPs at the same venue [ ] These bikes were really the stars of the race:






My dad in the middle. He was joining me for the first time in about 20 years ! The whole way up to this race was like a time shift for me: we spent so many hours together wrenching on OUR old bike just like back in the day. Biiiig fun. Having him around was really cool and he too enjoyed the laid back atmosphere. Just an example: we listened to italian music in the paddock rather than heavy beats....you got invited here and there to eat or have a coffee...or just a chat about bikes and such. Awesome !




All that remains now are some good memories and some nice colours on my Messico exhaust [ ]

Some more pics while riding the VRP

Next year i plan on doing the whole italian vintage championships and to do so i have these jerseys made:

Last year i was a lucky guy the italians let me compete at that race in Montevarcchi since my bike was still outfitted with a '90 Mugen engine. But it was clear that for 2016 i had to get a good running '89 ATAC engine. I already have that sweet stock cylinder ported but let's be honest - my bike literally screams for a Mugen and that's also what i raced with back in the day. So i was looking around for a looong time and finally scored a brandnew (!), '89 Mugen kit.

The only problem is - i was lucky to find this Mugen but not so lucky when shattering my right wrist in pieces just before christmas. It got operated and they put some nice titanium and bolts in there...but it will be a couple of months before i can use my hand at its fullest and we still don't know if all the movement will be there again or if i'll be handicapped somehow.I already had limited movement from another bad injury 25 years ago...so i just hope it gets back to where it was or at least close to that.





Some nicer pictures to get me motivated in rehab: