76 Honda CR125 Elsinore Build

Got the new Fox tank decal on the bike and it looks awesome. I ended up routing the petcock on the opposite side to clear the exhaust (works out great). I also got a chance to ride the bike for the first time and my impression is that the power hits hard in the middle...really hard. I weigh 175lbs and the bike easily pulls me around on one wheel through 4th gear. In fact, you really have to pay attention or the bike will get away from you. More to come on this but here are some photos I took today. Mike

I know some folks have commented on my suspension so let me clear something up, Honda did have two CR125's that Marty Smith rode in 76 that had more than 10" of suspension travel and pictures of those bikes is attached below. The problem or at least with AHRMA is that their rules apply to production motorcycles and these were Works bikes. So while they existed and were raced against privateers, they do not meet the AHRMA standard for Historic racing which is is a shame.

Just a quick update on the G.E.M. reed cage. There is some good and bad. The bad first, the bike refuses to run correctly with the 34mm carb. I have set the floats and jetted it numerous times and it only wants to run in the mid to top which is insanely fast, but not practical (unless you are on a wide open track). The worst part was that I could not get it to idle. Now for the good...somewhat, I put a 32mm Mikuni on and the bike runs like a champ. It still has the serious mid range hit that to caught me unbenknownist (is that a word?), and almost put me on my back at 175lbs. I have lost some top end, but it still hits pretty hard in the middle and keeps pulling. I need to richin the pilot a jet size or two and then I'll try the Mototek (I put the stock CDI on for the jetting). More to come, but this looks to be a pretty fun race bike. Mike

I just finished jetting the bike and ended up going up to a 45 pilot (AHRMA361 your jetting specs were perfect...thanks!). Below is a photo took along with a video of the bike running (I was about out of gas so it revved a little high), but the motor is awesome and sounds great. I put Mototek CD125 back on it, but I'm not 100% certain I like it over the stock setup (more testing will be required to determine this). Mike



Here's a link to the video of the bike running


https://www.youtube.com/watch?v=FHH4hghwql4

Below is a photo of the Mototek installation instructions for the CD125. I also have a couple of these and the one on my 77 RM125 works great, however I think I might end up having to advance my timing on my Elsinore because while it works it does not pull past the rev limiter (more to come). Nice Penton too, if you plan on putting one on the Penton, you may also want to look into a PVL. I have a PVL on my 80 RM125 and the bike never seems to to shut off, it just keeps pulling (amazing). I know the early Pentons (around 74) can be made to haul ass. A few years ago Tommy Benoklin showed up at Gaterback on one and proceeded to smoke everyone (even the modern bikes). I have no idea what he had in that motor, but he likely had some serious port work and possibly a PVL. A couple of years ago an AHRMA A rider who gave Guy Cooper fits at MX Rewind a few years ago was behind me on a 74 YZ125. I was riding a 98 RM250 and the guy came up on me and showed me a wheel so I pulled away and there he was showing me a wheel at the next turn. This went on for about 5 laps until I got tired and pulled off. The guy riding the bike told me the motor was stock (he only had Works shocks on it). I wasn't buying it because that bike was moving way too fast, so I know these early bikes can be made to go pretty fast.

Below is a photo of the Mototek installation instructions for the CD125. I also have a couple of these and the one on my 77 RM125 works great, however I think I might end up having to advance my timing on my Elsinore because while it works it does not pull past the rev limiter (more to come). Nice Penton too, if you plan on putting one on the Penton, you may also want to look into a PVL. I have a PVL on my 80 RM125 and the bike never seems to to shut off, it just keeps pulling (amazing). I know the early Pentons (around 74) can be made to haul ass. A few years ago Tommy Benoklin showed up at Gaterback on one and proceeded to smoke everyone (even the modern bikes). I have no idea what he had in that motor, but he likely had some serious port work and possibly a PVL. A couple of years ago an AHRMA A rider who gave Guy Cooper fits at MX Rewind a few years ago was behind me on a 74 YZ125. I was riding a 98 RM250 and the guy came up on me and showed me a wheel so I pulled away and there he was showing me a wheel at the next turn. This went on for about 5 laps until I got tired and pulled off. The guy riding the bike told me the motor was stock (he only had Works shocks on it). I wasn't buying it because that bike was moving way too fast, so I know these early bikes can be made to go pretty fast.

I want to first say that I am sooo glad I found this forum last year because this is a place where you can reach out to people that not only ride, but also wrench on their bikes, which is how we did 40 years ago when I was coming up in the 70s, so I just want to thank everyone of you for chiming in. Now to the bike; I had last got the bike working correctly with the stock CDI and a 32mm carb. I then put a Mototek CD125 on the bike that worked until I attempted to adjust the timing according to the Mototek instructions. That left me with a bike that would not run off the choke. I blew the carb out, cleaned the jets and nothing was working. I put the stock CDI back on and it was still not working with the 32mm carb so I had a few 34mm carbs lying around and decided to try a different one and bingo it works fine.
The bike does not pull as hard as I think it should in the middle so I’m going to play with the needle a bit and maybe even advance the timing. This is definitely not a bike for fast tracks as the power is really in the middle, but on a track like say Lake Sugar tree where you don’t have a lot of long straights (just some technical sections), I think this bike will more than get the job done. Thanks again to everyone for your help, Mike

Swatdoc,

Sorry I am just now getting back to you as I just moved from VA to Las Vegas during that time and hadn't been checking Vital or my email for some time (sorry). That roller looks pretty cool, but it took me a little bit of time to figure out how to make the whole skateboard tensioner work (thanks for sharing the photo of your bike), but I have it working now so I won't be needing the forward roller. You know, this is the second bike I have seen with a custom reed valve on it. I wonder if it's the same guy out of CA that was selling a Marty Smith 76 RC2 tribute bike on ebay earlier this year? I think those forks while way cool are only like 36mm or so. Too bad he can't make some in 38mm (that would be kiiler for jumping). Cheers, Mike

Video of the 76 Mugen kitted Elsinore running! I still hope to race this bike at some point now that I live out west (maybe SO CAL), but I recently had some health issues that set me back. I'm getting better but it's been months since I touched a wrench or a bike until I jetted this bike out this past weekend (feels good).

Here's a walkaround video link

https://www.youtube.com/watch?v=PwwCK6YzqTc

Here's a link to the bike running

https://www.youtube.com/watch?v=BWgVgV_s2tY

Cheers, Mike

Holly airbox arrived! I was using an alloy box by Geoff Morris, which is only slightly heavier than the fiberglass Holly box. I purchased the Holly box because I want to experiment with a Mugen up pipe that has to pass through the airbox. There are a couple of things I want to pass on about the Holly box. First, it looks great, however I own one other aftermarket airbag (DG racing) that is made of plastic and I can tell you it seems the DG box is more durable then the fiberglass Holly box. Also, the Holly box appears to be made for a standard CR125 and not a Mugen kitted CR (which I have). So if you don't have a Mugen or reedvalve top end on your bike then you should be finem but it's a tight fit for a reedvalve top end. I'm going to keep my alloy box just in case because the Holly box is very thin fiberglass and I want to see how it will hold up to jumping. The Holly box is also a bit bigger than the alloy Morris box so we'll just have to see, but it does look good!

Swatdoc,

i used a flexible coupler I purchased at Home Depot that I had to modify the hell out to work. There's really only about 2.5 inches (if that) between the carb & the rear airbox is completely against the frame. I've not seen the VMX intake but it's going to have to be fairly small to work with this setup. I have no idea what they used for these Mugen top ends back in the day but what made out the flexible coupler works. I'd say get your jetting as close as you can with the airbox so all you have to play with is the needle, which is easily assessble. Mike

Swatdoc,

Here is a picture of the hose I used (it cost less than $3.00 at Home Depot).



And here is what it looks like on the bike, so as you can see it took a lot of manipluating with a heat gun/cutting to make it work, but in the end it does work and is functional. You may want to reach out to some of the other guys like Newman who have an intake boot that works. I could not find one so I just do what I always do and make my own...

Rob,

I will have to get back to you this weekend maybe but I used a 34mm carb and I settled on a 35 pilot & and with needle on the top clip (leaned). The air screw is 2.5 out and I went to a 2.0 slide. The main is the unknown (I'll have to pull the carb to take a look). But the bike runs really crisp on top (I'll get back to you). Mike

I ended up making some slight changes to the jetting and here are numbers:

Main jet: 300
Pilot Jet: 40 (however, next time I go into the carb I'll likely go with a 37.5.(40 is good but could be a little leaner)
Needle clip: 2nd position from the top
Airscrew: 2.75 turns out (yeah, that's why I'm thinking 37.5 on the pilot

The bike runs suprising well (pulls really hard). I am going to try a full up pipe (Mugen) at some point because the pipe i have now (Fox Protopipe), does pull well throughout the range with decent overev, however the bike does have a bit more grunt on the bottom due to the short pipe, so I want try a Mugen or another up pipe to see the difference. I weigh around 175lbs and the bike spun the rear tire (on the road) without me trying to (it hooked up pretty hard off throttle). And because I had to take the pipe off and the airbox partially to jet, I took some better photos of the hose I used for the airbox carb boot. Mike







Take a look at this plug, it's a new plug (maybe 4 times running on it, but as you can see it's starting to get that brown chocolate look you want. As I said, the bike runs really crisp and pull hard through all the gears!