Hi 2SW! Just re-joined the forum after a couple of years in the wilderness after I sold by GT750 & RD400 projects to fellow forum members. Thought you might be interested in this, my latest project. Picked up a 1987 SRX250 roller a while back. Brought back a RD250 motor from Barber VF this year and decided to do the transplant. So far so good!
A good combo.
THAT, friends and neighbors, is going to be super cool. :thumbs: :vroom: :burnout:
I had the same thought a few years ago, posted it on the old forum. Then someone came along and offered me way too much for the SRX! Looking forward to this thread.
Cool! :clap: What Yamaha should have built back in the day.
Might even deserve a 350 top end too. :wink:
:agree:
Started dismantling the RD250 motor. Should have loosened the drive sprocket while still in the frame but got ahead of myself. That thing was on as tight as a camel's arse in a sandstorm so had to channel my inner McGyver. I didn't want to risk damaging the casings so I backed the motor up to the vice and used an old chain I had lying around. Applied some heat to the sprocket & nut and off she came.
Smart!
Air Tech has a full fairing option. https://www.airtech-streamlining.com/yamaha-fairings-seats-fenders-parts/86srx25.htm
Good to know! Thanks for that
The RD250 motor came mounted in a chopped frame. So I was able to graft the bottom section with the front engine mounting points onto the SRX frame. Here is after cleaning up the initial tack welding and adding some bracing around the headstock.
Nice! :clap:
I'm always amazed the amount of brackets and tabs on a frame. Looks like a good start,
I like cross-pollinating. Basic hot rodding at it's best.
Cheers, 50gary
First experience of vapor blasting and I am well pleased (in the words of Allen Millyard)
Where is your vapor blasting being done?
I found a local shop that does it:
http://www.vaporblastingnc.com/
Check out the Gallery for pics
I think this rear sprocket might need replacing. I've never seen one this bad before. There's a lot of red on this bike so I couldn't resist throwing in a pic of the "blue" in the garage :vroom:
It does not appear that your pipes will clear the tire unless you do some real fancyfabrication
.
I mean... might as well take it all the way. :dawg:
Don't forget the red sprocket nuts!
A little more progress. Got the RD coils mounted up. Tested them and I have sparks so that's good. Carbs all cleaned up and mounted. Some more parts on the way so next steps will be replacing the points (badly pitted), setting timing, finish the oil pump install with new lines. Then a test start!
I've hit a snag with the build and I would appreciate some input. I was going to make an offset drive sprocket for the front to match up with the SRX rear. However when I mocked it up the clutch actuator mechanism will hit the chain. Not good. Looking into possibility of moving rear sprocket inboard about 10mm but that looks challenging. Ideas welcome!
Hmmm...?
Potentially a game of small gains. 10mm is a lot to move/alter one piece but maybe a few mm by primary, rear sprocket and possibly an engine shift by a few mm would see the chain align?
If there is some potential to offset primary 3mm?
Theres potential for the rear to be inset 3 mm* and shift the engine to the left 3mm.
Give or take there's your 10mm.
* watch out for chain to tyre clearance.
Thats all I got....good luck.
Space the engine cover and make a longer clutch pushrod, then go ahead with the offset sprocket?
Yeah, you'd have to do someting with the shift shaft, too. :umm:
hi,
looking at the very nice way that you fabricated the engine mounts it would be a shame to rip them apart to move the engine over 10mm. but would it be possible to machine 10mm off of the engine mounts on the engine and then slide the engine over on the bolts and use spacers in the other side?
i have built half a dozen hybrids and have always found that it is best to get the engine to line up rather than start spacing everything else. even if it means offsetting the engine by a small amount.
cheers
les.
Long way to go but taking shape!
Got the drive train lined up. Went the route of offsetting the rear sprocket in the end. Two perfectly good JT sprockets were butchered but everything lines up nicely with a 10mm spacer between them. In case you're wondering, the current rear tire is now rubbing the chain but it is way wider than it should be so that will be replaced with stock size (90/90-18).
very cool. i would recommend welding that all together. :twocents:
Slow going on the project lately due to life getting in the way, but did manage to work on the foot controls a bit. I had a set of rearsets left over from a GT750 project. I cut some new brackets from 1/2 inch ally plate. I didn't have to modify the hanging brackets on the chambers which was a bonus.
Coming along nicely. :)
This is rad!
A friend had an SRX6 back in the day and I was seriously impressed with the chassis. Totally flickable and a definite upgrade over the RD platform. Looking forward to seeing how this turns out!
Quote from: BlueR32 on December 23, 2021, 03:29:40 PM
I think this rear sprocket might need replacing. I've never seen one this bad before. There's a lot of red on this bike so I couldn't resist throwing in a pic of the "blue" in the garage :vroom:
Do you get the VJ23 out much and use it?
Did you bring it in, or have someone do that?
Few and far between over here.
Do you get the VJ23 out much and use it?
Did you bring it in, or have someone do that?
Few and far between over here.
[/quote]
Yes indeed! She gets out almost every weekend. Probably one of the most fun bikes I have ever ridden. Also use it for track days. I didn't bring it in. Bought it off a WERA 13x Forum member last year January.
http://forums.13x.com/index.php?threads/1996-suzuki-rgv250-sp.365862/
It might be an optical illusion, but that chain doesn't look quite straight. maybe it's just channeling its inner pride month... :whistle:
Try it without the chain on and see if the sprockets are in line. I often use a 3 foot length of 1/2" rod or angle aluminum. Hold it tight against the front sprocket and see how it lines up at the wheel.
The other thing is that an RD chain will usually clear the rear tire even if it's a couple of sizes larger than stock. It should just touch a 130 or so tire. My last TZ rubbed on a 130/65 Avon with stock front sprocket and chains aligned and it's basically the same motor.
As mark mentioned, that set up needs to be stronger and welding would be a start. If not, it will distort and probably fail in use.
Nice project BTW.
Thanks for the great suggestions all! That tire is a 130 and the chain is just touching. Stock SRX rear is 100 so I have some options. I will check the sprocket alignment for sure. Right now its just mocked up with some 12mm plastic spacers which I had lying around but the plan is to get the exact spacer size needed once everything is lined up. The final spacers will be steel and I will get it all welded up as suggested. Don't all hold your breath waiting for the next update as this weekend I am heading to Colorado for 2 months to escape the humidity here in NC. Looking forward to exploring CO on 2 wheels:)
Time for a project update. Slow progress but wiring is sorted, motor runs, foot controls are mostly figured out. Almost at the point of tearing down to do frame cleanup and paint prep.
Lookin' good! Nice work. :clap:
Yup, I like it; lookin' like a motorcycle!
Love this! Always liked those crazy SRX but couldn't ever get my hands on one. This will be awesome once complete!
It's been a while since last update and not a lot to report. The project is stripped down and next step will be cleanup and prep for painting. I retired end of June and I'm in CO for the summer so will get back into it in the Fall. Meanwhile I did a trip back to the homeland (Ireland) in April and rode the south west area with my brother and some friends. Remarkably we had no rain the entire week. A highlight of the trip was meeting up with Forum Member @elliotles1 in Glengarriff. Stay tuned!
Quote from: BlueR32 on July 19, 2023, 08:46:34 AMIt's been a while since last update and not a lot to report. The project is stripped down and next step will be cleanup and prep for painting. I retired end of June and I'm in CO for the summer so will get back into it in the Fall. Meanwhile I did a trip back to the homeland (Ireland) in April and rode the south west area with my brother and some friends. Remarkably we had no rain the entire week. A highlight of the trip was meeting up with Forum Member @elliotles1 in Glengarriff. Stay tuned!
Congrats on your retirement :cheers:
The IRL trip sounds like a great time. Beautiful area! And really cool that you were able to meet up with Les.
There's an SRX a couple of hours from me on marketplace, and I know a guy with a spare engine (or two)...I DO NOT need another project! Oh, dear.
BlueR32
was great to catch up, thanks for calling in. its raining alright now!
i am currently selling two or three bikes to fund the next one. i will keep following yours, good luck with it.
might catch up with the brother for a spin sometime.
cheers
les.
Perfect frame painting day yesterday here in NC! Nice & warm, low humidity and no pollen.
A bit more progress. Got all the red paint off wheels & fork lowers (never again). Going to stick with the raw ally finish I think. Before & after pics below:
Looks great! How did you prep the metal for painting. Sandblast, OSPHO, primer?
Nice, I like it! I was always hoping to 1 day do a RD motor transplant into a more modern chassis- but not too modern where they can lose the vintage coolness. Had targeted Kawasaki GPZ305 for the transplant recipient but too many other things sucked up my time over the decades and I'm realizing this will probably never happen :sad:
Makes me want to find an SRX donor chassis
thats a lot of real estate above that motor... you could def add to the fuel tank for more capacity if so desired, or stuff the oil tank down in there. this should be good. the wheels do look great in silver
could also run a pair of crossover up pipes though there :wink:
Quote from: RDnuTZ on May 25, 2024, 10:20:37 AMcould also run a pair of crossover up pipes though there :wink:
ooh. high pipes, bleed silencer style (side) with mufflers aimed down and back.
yep, in the MX world we called them Snail Pipes. Dave Miller (Miller Mano) was the earliest builder I know of to offer that side silencer with blocked off end cone style way back in 1976 for YZ125s
Some progress since last update in May 2024. I painted the tank, rear seat cowl and front fairing with a gray primer just to get a consistent look. Still work to be done. Mostly electrics, oil pump setup, foot controls & chamber mounting and then final paint.
Looking good!
She's almost ready for the road.
I love a good Frakenbike, and I love how yours is coming together. Keep up the good work!
Quote from: Guygrrr on March 29, 2025, 07:11:09 PMI love a good Frakenbike, and I love how yours is coming together. Keep up the good work!
Thanks! I'm at a point where I'm trying to decide whether to keep it or sell as-is. I've done everything so far myself but a proper paint job is beyond my capability and budget. Thoughts/ideas welcome!
Well, it's been a while but in the end I've decided to keep it and finish the job. Body parts are out for painting. I also went through the whole surety bond process to get a title in NC and I now have it. That was interesting as it is a custom so License & Theft had to come out and do an inspection. Will post some more pics when I get the painted stuff back.
Quote from: BlueR32 on August 20, 2025, 09:09:16 PMWell, it's been a while but in the end I've decided to keep it and finish the job. Body parts are out for painting. I also went through the whole surety bond process to get a title in NC and I now have it. That was interesting as it is a custom so License & Theft had to come out and do an inspection. Will post some more pics when I get the painted stuff back.
Excellent :clap:
Quote from: BlueR32 on August 20, 2025, 09:09:16 PMWell, it's been a while but in the end I've decided to keep it and finish the job.
Cool! :thumbs:
Body parts are out for painting. Will update when I get them back. Otherwise it's pretty much complete except for a few minor tweaks.
:cheerleader:
:clap:
Can't wait to see it complete
Looking good! Neat idea for a RD engine.
I got my road racing license on a SRX600, back in the day.
Crazy-bad photo, but you get the idea -
20250412_183045.jpg
Always thought the SRX250 looked like fun - but it was painfully slow.
My friend is doing the paintwork for me had some challenges with the tank. After he stripped the paint to prep it he discovered a large area of "filler" which he removed and found a large number of holes. We were mystified as to what could have caused such carnage. In any case, he came up with a clever solution using old Phillips head screws. He cut them flush and welded around them to seal the holes. He then pressure tested the tank before painting. The last pic is right before he applied clear coat.
old school bodywork method of pulling dents was drill small holes and use slide hammer with screw bit end to pull out dents. Typically using heat as you go. The holes also allowed the Bondo to grip better, but I wouldn't want it on my gas tank. Usually, they brazed the holes shut before filler applied. More modern method is to tack on slender rods on outside of tank and use slide hammer pulling on the rods. No holes needed for newer method.
That tank after paint :smiley: :thumbs:
That is one top hybrid project.
Quote from: 2steve on October 17, 2025, 09:54:50 AMThat tank after paint :smiley: :thumbs:
That is one top hybrid project.
Absolutely agree!
Very nice! :clap:
Work of ART! Your painter friend is definitely tops!
Ready for some road testing! It's been a long journey to get here but I think it's been worth it.
Looks Great :clap: I really like the dash board :thumbs:
That is really cool. It turned out great.
that looks SOOO much better than the original everything painted orange photo.
Absolutely gorgeous. Beautiful work :patriot: :patriot:
yeah that's a super cool result
Thank you all for the kind words & compliments! It's taken forever, but in a way that was deliberate so I wouldn't be tempted to rush it and then have to find another project haha. There's some work to be done on the front forks as there is some bad stiction so that's next. You never know but if the planets align and the dates work out in 2026 I would like to make an appearance with it at 2-stroke week. Fingers crossed!
Here's a couple of pics: what I started with and how she turned out
Wow, that's gorgeous. Nicely done!
Wow - quite the transformation!
Good job making it all come together.
Stunning difference. Should be a hoot to ride.
Awesome result! :whoop: The before and after shows how much work went into it. Congrats on completing it :vroom: