Who thinks it will start? Please SUBSCRIBE and LIKE the video if you enjoyed! It really helps me out a lot! Check out my Instagram: 2_vintage_ Thank you for all the support!

Try this: 1. Check for spark. One kick is ample. 2. Order new gasket set, seals and bearings. 3. Remove engine from frame and get it on the bench. 4. Completely strip and inspect, clean and replace all seals, bearings and any broken or worn-out parts. Oil seals are simply not designed to last 3 decades! 5. Reassemble. 6. Put engine back in frame 7. Check timing with a dial gauge using timing degrees off the internet. 8. Clean carb and replace all jets making sure you have the right sizes. They cost pennies. Never run a 2 stroke without an air filter. Honest mate, it's a lot more satisfying and less time-consuming than endless fault-finding and troubleshooting. 😀👍

If you hold the soldering iron on the wire while applying the solder, it will flow into the splice a lot easier. 👍🏻

It’s a two-stroke Derek, being over filled on oil cannot affect how the boat runs the crank case is completely sealed off from the Engine cylinder

Line up the lines and your in time . 1979 RM 400 rider ! Bought it new in 79 ! Still have it and a 1980 . Best motocrosser in the day .

I love seeing you go back to the roots of what me and a friend of mine were doing 25 years ago. Digging up barn bikes and riding the shit out of them if they’d run until they blew up

Yes it will start , first bike I had was a 1979 rm 125 she was beautiful I am 53 years I WANT one again 👍😆

It doesn't sound like you have a spark issue. It's acting exactly like the choke is on.

Man, I dig your channel. Love getting into the details with you. Used to really enjoy working on my bike with my dad, brings back great memories.

I was really looking forward to this video man, thanks a bunch for uploading it.

Cant get enough of vintage bikes. Love em

That's a '79. Check the reed valves for your bogging problem, they're probably not fluttering like they should after sitting for so long. Congrats on getting it started. (Oops, spoiler alert!!)

This was my first bike here in new zealand, soo cool to see one coming back to life

I can’t wait to get mine up and running!!

cannot believe how lucky u are getting them bikes.happy for u.u do an amzing video all of the videos are really thorough as u explain properly

Such a satasfying video. Just found your channel and joining your community. I support all 2 wheeled content creators like us. Keep riding, keep happy! Excited to see what you post next.

*Watching You is like making my dream come true. I'd love to buy Old dirt bikes and fix them up to bring them to their glory days. One day I'd love to fix some up. Keep up your amazing and inspiring content.* ☺

Before I watch ,I have full faith in you getting the RM going 👍👍

Yall get it going don't worry about it

Thanks for the videos. I love this kinda stuff and have learned allot from checking out your videos. I Bought an 86 Suzuki dr100 this spring that didn't run and got it running. Didn't take much. More TLC than anything. I'd like to restore it but parts are extremely hard to find at a reasonable price.

when you're soldering, you should heat the wires up and let the solder flow into the wires rather than putting a layer on. They'll hold much better if the solder works its way into the wire

If it was a crank seal the bike would be smoking a lot more than what it is. Most likely it’s your carburetor settings or the timing is slightly off

Cdi is everything without the right one it wont have the right firing order or sequence hope ya get it brother love the vintage bikes

Awesome! I owned and rebuilt one of those many years ago! Powerband was insane, when it hits just hold on!

I bought a brand new 1976 rm 125. Top of the line back then. 6 speed gearbox. It was top of the line, then.

thank you also for bringing me back in time

Brilliant looking forward to this 👍

My first full size motocrosser. It was a great bike. In its time it was state of the art. The RM’s and YZ’s were head and shoulders the two best motocross lineups back then.

That little trick with the air chisel was genius.

Can’t wait to see your first ride

I miss my 82 rm, was a great bike

that will def start up!! love your videos man :)

When I was about 11 I bought a xr75 from a guy for $20 and some fake Oakley sun glasses. It didn't run, but I worked on it until I got it running. A few months later it caught fire from a backfire and homemade intake tube (a bicycle innertube) letting the fire out to where the carb leaked. I would fill the carb bowl and shut off the gas cause it leaked. One day I'm riding it with my friend and it ran out of gas. A construction worker filled the tank for me, and I headed off for the house about 3 or 4 mins away. I got to my yard and was hoping to get the gas shut off before anything bad happened bit it was too late, and being it had a whole tank of gas continuously leaking from the carb it was hard to put out. So I got rid of that and bought for $20 dollers! A 86 kx 80! It didn't have a cdi, so I put one from a older Suzuki model I can't remember what model but it was a 2stroke 80cc, and wouldn't you know it it fired up! I can't remember now why... but the throttle would get stuck open so We put a thick string around the sparkplug boot, too yank it off the plug when it would happen! It happened to me a few times! 😆 But boy did I love working on those things! I was 10-13 so didn't have any money but I could rig it up with superglue and duct tape! Great video man! I think it time to find me a used fixer upper dirt bike! Keep up the great work!

Use flux when soldering and heat the wire, then add the solder. Let the solder flow into the joint, It's not paint. To prevent the heatshrink shrinking, put it on the longer piece of wire so it's further away from the heat. Gonna be a nice bike when you are done.

1979 I definitely think it’s a 79 thanks for your great videos they are all excellent 🤘☘️🇺🇸

I wonder if the timing needs to be advanced a couple degrees. Great job on this project! From rust to riches!!

This bike has done very little ,you found a really tidy bike 1979.I had 78 many years ago first thing I rode with power band!! Happy days 👍

that guy was smart. he made you buy both bikes for the parts for the 125.

Ok that makes sense if your using the wrong parts. I look forward to you riding it!

You should start using a dial gauge indicator for timing. If it is advanced at all, you can put a hole in the piston.

Love this bike!

One little tip. I notice in a lot of your videos that you give it throttle as you kick the bike over. This often makes it harder to start the bike. It's normally easier to get it to fire and then if it fires, THEN give it gas if it needs it.

Took my jug to a shop yesterday and have to get it bored to the next size bigger!! Have it back in a week or so!

Cool! getting close.

Rm 250 on the trailer looks like a '77 or early '78 model. Your Rm125 uses two intake systems piston port low end, then 'case reed' (you've not checked the reeds or reed lands yet) opens up for mid/top end. The cdi and correct stator part no.s can be identified from incisive googling presuming the part no. is still legible on your cdi. I think you can buy complete ignition and Boyesen (rad valve?) reed systems both cheaper then stock even if you can find them.

Totally correct you need the right CDI unit for that yr of bike, they were a big prob bk then..

My first bike wuz a '80 RM80! had her for like 16 years till she died onna logging road somewhere. Energy can't be destroyed

I've hesitated in the past to correct your starting procedure on two strokes. Do not twist the throttle with the enrichment knob pulled out. It's not a choke......it's an enrichment circuit that only functions properly with the throttle position at idle.

Love to see the new finds, you're doing awesome man. Props to you! No sponsor from good ol' dubya d40 yet eh? Lol

Nice fix but I can't stop drooling over that 350x in the background ✌

Thats a rocket ship when running, if the carb is correct and it won't rev high it will be the high revs coil failing in the stator assembly. Had exactly the same problem back in the day on the exact same machine!

Start with the fundamentals. check compression, do a leak down test if you know how. Leak down will tell you if the main seals leak or you have a gasket leak. use a new plug and check the color of the spark. Light blue is optimal. check the reeds. check the timing. and use some good gas. You cleaned the carb and the pipe isnt the issue unless its crushed.Check the jetting specs too never assume the jetting is correct. Could be a way big main jet with high float level..

Another smasher top content bud. I think most definitely the cdi.

Do yourself a favor and order a dial gauge indicator while your at it. They’re like $50. They are a necessity. Once you’ve used one, you’ll see what I mean. There’s nothing like a properly timed bike.

its your air fuel mix you need to restrict some air coming in an air filter might do the trick!!!! has happpened to me with 2 stroke bikes all the time

Can't wait for diagnosis I was saying main jet if not standard. Or wrong stator

Those old ' zooks have really nice lines to them, good looking bikes. Another vintage cycle rises again! Yeah! It came from the 70' s .....

It's a live great job bro

Hey great video here’s a little tip if it’s running kind of crappy that little tab on the bottom of the carb comes in contact with the motor and foams up the gas so grind it down a few milameters so it’s not touching it

Really hope you can figure it out. You're probably right about the CDI and I wonder if changing the timing would help with the 250 stator and CDI?

u can solder the end back on the throttle cable joe

ahhh my dream bike

Spray startingfuild around head and cylinder while running see if it revs up. Gaskets could be blown. Could be e plug

Careful with timing.....to low it will bog out.....to high it will burn a hole right thru the top of the piston......happened to me twice on wiseco new builts......cost me 2 pistons before getting it timed right.

Alot of older bikes have the year stamped into the head tube

Great videos Joe, love it, looks like she might be time for a new pair of work shorts eh? I mean your on KZfaq so try n look presentable lol

Awesome video

Make sure your putting a washer under the main jet!! Also check the main jet size...

You need to check those reeds out and check the carb sounds like not enough fuel or broken reeds

Thanks for the great video stay safe brother

I am from Sheboygan Wi. My dads first dirtbike was a 1979 Suzuki rm125. I will buy this off of you when you’re done with it

Yeah that CDI and stater definitely looks like the one I had on my 79 arm 250 and I had my stater go out on my RM 250 well half of it and I had to replace it it would idle but soon as you touch the throttle it would die and it also would run hot just at idle but once I replace the stater ran like a champ

Im going to have to go with, it’s the float level in the carb. Just my opinion.

New plug I would before anything

If you do suspect the air filter 30 or $40 air filters a lot cheaper than an engine rebuild just swap the dang thing out with a new one

Def sounds like the issue Brother. You got this tho!

LOL WOW What a great deal! Got your parts too! Be safe Brother :)

And I've wired up different cdi boxes they all work..

Got that hoagie runnin!! 🍋🔥

Definitely a 1979 - the 1980 had a smaller rear fender, and the 1978 has a different gas tank

May need an air filter to help with vacuum

Had the same bike and same problem. In my case it was the reed valve. Debris got stuck in them. Check your reeds!!

Just so you know the C. D. I is built into the coil on this. The coil has the cdi in the coil .so if the stator wires run too the ignition coil and you have spark you do not need too add a C. D. I to the bike .

I have to do the crank seal on my 01 CR125. If you let it sit for a while it starts out super rich and smokes like crazy and then evens out. It's gotten real bad where it has a constant rich condition no matter how much you lean it out. Replacing it this weekend.

By the condition of that carb It's a carb issue. Not getting enough fuel. Your idle circuit is working but secondary circuit is not. Try spraying fuel in the carb at WOT and that will tell you for sure. This test will also rule out reed problems. Easy peasy!

Doesn't smoke enough for crank seal. And even if timing is off little it would run better than that unless something isn't right. Pull cylinder and check reeds might have broken one

It’s FOR SURE THE STATOR TIMING

Yeah that's what I think it is too

thats call cold soldering what keep it together but in time broked much easier than hot soldering.

I would look at the reed valves.

Its sat for a very long time it may just need running for a while to get the seals hot enough to seal the engine up good.

It’s definitely the timing IMO sounds like it’s not advancing with the rpms

Must be hot if they scratched the Vin off

79 almost the year i was born....1978 for me just turned 43

Wow esta fue la primera moto que manejé en mi vida y después nadie me bajaría de una.

Definitely a 79 from the chain tensioners and roller on the swing arm 80 has a different bottom chain guide

Should have loosened the screws on the stator to where it's held in place. But you can still turn it. Start the engine. Very slowly turn the stator changing the timing. Possibly the timing marks on the 250 are in a slightly different spot. There's not enough difference between the two bikes that it should matter. You've got spark. The only other thing the cdi controls is the timing curve. That should be about the same on either. If timed right has to work

The rm125 I had in tht year the black lead tht comes out the stator was at the top

Try a air filter and or advance the timing possibly

yea, I have several friends with Suzuki 125 's of that vintage and it is not uncommon for the cdi box to go out, It acts just like that too.