Crazy I been watching you for like 3 years now. You’ve came a long way since then you and your wife. Congrats fr im gonna keep on watching and supporting. You help a lot of young mechanics out

ayyy i was right, i had a yfz give me an issue like this except way more extreme, would run fine in neutral but if you kicked it into gear would die instantly, love watching your videos, as a quad and dirtbike mechanic its good to see other peoples experiences, my uncle always taught me "smart to learn from your own mistakes, but even smarter to learn from someone elses" watching your videos has given me experience i would have never got if you didnt go thru it and record it so i can watch, amazing work man

For measuring a low resistance, like a coil of 0.3 ohms, we need to subtract the resistance of the leads. Touch the two leads tightly together and measure the resistance. The leads are usually around 0.2 ohms which should be subtracted from the coil reading. So if we measure 0.5 for the coil, then it is actually 0.3.

if im honest i dont think you have got to the problem, your running a smaller than factory jet to compensate for the leak in the carb mid body gasket. That internal leak will only get worse as the gasket turns to more mush, the RFS engine has a fearsome top end power punch which doesnt quite seem to be there. Open the float bowl remove the floats and you will see 2 small screws the hold the top and mid body parts together. What you will see between the two parts is a very old mushy rubber thing that was a gasket 20 years ago. But fair play you got it running much better but i just know from the 4 KTM EXC bikes i have owned with the RFS engine and the series 1 FCR slant carb have all had the same problem. And while im being honest its dam near impossible to fix even though you can sometimes buy the gasket required, it was never meant to be pulled apart. There are a few gents in the States who can fix them and they can be found on forums. Myself i tried, i failed and brought 4 very expensive replacement carbs.

Joe has so much more experience and knowledge than me but I love the DIY feel. I feel like I could do what Joe does just because he’s so casual about everything. But I don’t have a cool garage. Or big field to test stuff.

It's not hitting the rev limiter...it's cutting out of spark. That's why your spark plug looks rich. Cuz fuel is still flowing in with no spark.

Love what you've done with your shop. Looks nice and better organized.

So I finished watching the video. And there is a lot more power to be had on that beast. You should have a hard time keeping the front tire on the ground even half way through 3rd gear.

Electrical Engineer chiming in here. When reading resistance of coils and wires, you should always attempt to ground out the coil to dissipate any parasitic charge build up by the coil and capacitor before making resistance measurements. Just a tip, when measuring below 1 ohm or low resistance values, you must anticipate the lead resistance of the actual instrument leads to account for all the resistance in the circuit measured. Usually on top end meters (Fluke 87V, Brymen, etc) they have a REL function to cancel out this. Usually it's 1-2 ohm. You short out the leads, hit the REL function, then measure. That way you have a dead accurate reading. Anyways I love your content and hard work! Keep up the good work!

Great video once again glad to see how you're checking the wiring I need to learn that!! Thanks

I'll admit it's better but it's still busting up. That is not the Rev limiter you hear. Nothing hits a Rev limiter that fast and in every gear.

Look at the stator .Breaks down under load when warm...may be the stator .Early KTM's ,this was common .Good luck

Glad you figured it out. Love your videos. I did not think a jet could make it run that bad off idle.

Pleased you got to the bottom of it Joe ! Sounds pretty good to be fare . I did think electrical too . You are becoming quite efficient in your repair work .God bless ya brother . Thanks for the update

Great vid man, not a lot of things you can’t fix watching your vids for the last 4 years😂 don’t miss any

Something is going on with that carburetor making it too rich. Stock jetting is 175 main / 48 pilot. If yours had a 172 main, someone had already leaned it out. I would tear that carb down and find out why it doesn't run on stock jetting

Check spark with a spark tester to make sure it is strong enough to jump a large gap. The spark plug is a small gap and is easily done until it is under load then it goes to missing.

Yeah, that's not fixed. The high idle followed by dropping idle is an indication of lean. Did you put that junk autolite plug back in it? I've seen those not burn under heavy fuel load. Fouled plug could also be explained by plug not able to handle the load of high RPM. In which case, original jet would have been correct.

Would have been nice to also see what the spark plug looks like after the jet change. Otherwise, great diagnosis and fix!

awesome! had same problem in my yamaha xt600, that needle is just wow!

When you tested the plug on the jug. Lol. Yea. Looks like it wasn't as strong as it could be,kinda bouncing around too ?? Maybe not.but coil ?!?

Props on taking the time to do both of these vids buddy !

NGL I don't always watch the entire videos, just don't have the time but glad you got it fixed! I always try to compare the main jets in bikes carbs to what is stock esp. a new to me bike, plug read actually told you the story on this one long ago unfortunately but that's mechanic life for ya. Damned if you do, damned if ya don't lol, at least it's fixed now though!

That's how much difference elevation makes to carb tuning 🤙 commented on the last video that factory jetting isn't necessarily perfect jetting for your climate and air pressure

Glad to see you bringing the ol RFS engine alive. It seems to running a lot better than your previous videos on it. I love my 2004 KTM 450 EXC RFS engine. I fully rebuild the entire motor last year. They've got so much power and torque in these motors and I've only hit the rev limiter on it a handful of times as it is. Amazingly fun and reliable motors

Love it mate, here in South Africa obtaining spares for these "old boys" is an issue. Love your channel and your patience...I would have wielded the flame thrower on many occasions!

It amazes me how many times people tinker with something trying to get more power then screw it all up and give up on the project. When all they have to do is go back to what made it run. All that work and it was jetting lol good running bike now

I wish I could've swapped ot the jets on my twin carbed 750 shadow like you can on that bike. I couldn't tell you how many times I pulled that sucker out and rejected after slapping velocity stacks and exhaust on it. Only to find out the diaphragms were pinched... but I'm a pro at it now! 😎

I wonder if the jetting being wrong is something to do with the pipe, the 02 400 exc came out with a dual pipe into a single muffler. Well done on the fix man!!

Bigger and more is not always better. Good troubleshooting on electrical and glad you got it licked. Ride it and sell it!

I had a similar problem with my car. We tried and tried and could never find the problem. We brought it in and it was a ground

If your really curious on the cc of the engine look and see if there is a stamp on the engine or just look up the model number

My heart went out to you watching this video as I have a 2014 KTM 450 I don't know whether you sorted out the problem or not but I think it's possibly the CDI unit but I'm sure you would have sorted it now but I just don't know anyway Happy Trails brother 💯🤟

You most certainly made it better but still not confirmed to be fixed. You short-shifted that bike each time, you never let it rev-out. I am guessing you will need to tweak it more. Better but not done.

Had the same problem, remove that air splitter from the back of the carb, aftermarket product that doesn't work

32:48 ... and no more complaints about the harsh shocks. fixing the jet issue must have solved the suspension "problem" also.

I know this is 6 months old but I would agree with some of the others posts. Definitely rebuild, new seals in the mid plate, make sure your accelerator pump is squirting correctly and at the right time. A lot of people do the Eddie Mod on the FCR1 carb because there is no real adjustment but with a lot of playing around and patience I was able to get mine perfect. Also while jetting the bike I have read you should really do that with the accelerator pump disconnected but I am certainly not a pro. I am just a guy with an opinion, trying to learn the best I can and most I can. The only way to do that is try and fail then you try and fail again. I restore old cars for a living but I love working on bikes, quads and anything with a small engine. It’s stress relief for me and invigorating when you get them running too notch!

Nice job, the $1300 bike turns out to have been a good deal.

Not that this is the problem but I've never seen you address that a spark plug under pressure can not spark when it does spark out of the head at times

Love your work Joe here from Tasmania

Week 5 in hospital your videos have kept me going

Your idle speed seems a little high, and doesn't come down off of WOT. Maybe it needs a larger low speed jet? You'll figure it out.

Those gloves seem pretty good but maybe a bit loose on the finger tips, so I got a glove recommendation: Maxiflex 34-874 black dipped nitrile. They have different types but my favs have gray fabric. The palm and fingers are straight black with a fine texture, but no pattern or anything. They fit perfectly to the fingers, you can text perfectly with them on they fit so good. Best fine detail gloves ever imo, compression fit. They stretch nicely so size large will fit bigger hands.

Yep..About 100 kilometers down the Elbe. Do I get that the stock netting is not working? After market parts or other problems? I'd say it's those brogans. I could use one of those to canoe down the Chattooga.

Hi , where are you getting your resistance readings for you coil from please

I could tell just by hearing it. Spark plugs don’t lie

The area that you live looks a lot like where i live, if i had to guess i would say northern Wisconsin. The terrain and trees are much like Northern Michigan where i live. Im just south of the bridge, not quite a yooper 😁

Wow ,long time no see ,you got a little shop /place now!

Great work Joe! That bike runs way better! 😎

love your work man

Great video and well done! Unfortunately, I learn more from your failures.

Really good power delivery creates great big smiles and is a safer riding experience. Very good.

Plug is black from a misfiring or bad coil. Starts fine,revs fine,carb should be fine. COIL or wiring to?!?

Good work man love the vide

It does sound rough , my mate had a RM 400 that sounded the same , Electrics fault coil and a dead wire ( broken under the plastic covering )

I Dont Know how u don’t blow some of these up just all pissed off chasing your tail on some if these. Great content anyhow buddy.

measuring resistance has a number of important points to note: 1) meter must be calibrated by putting probes firmly together and noting the error reading, which must then be deducted from the component reading. 2) resistance is only a guide, and when checking coils, inductors (chokes), inductive sensors and transformers, the value of inductance (Henries) is more important. Exemplia gracia.. an inductive pick up sensor may have a reading of 5 ohms and 500 turns (windings). If 1 winding is short-circuited, it would would be impossible to read the resitance (except with an LCR analyser), but would quench (kill) the value of induction, rendering the sensor useless. I love bikes, electronics, machining, fabrication/welding, inventing and.....!

hello, I have a beta 525 rr 2009 and it spins hard at the button (starts on the first pedal), I changed the electric motor, adjusted valves and it's still the same, do you think it could have it? should it be the unidirectional bearing or the stator?

Save yourself time and invest in some electronic diagnostic tools and an exhaust gas analyzer. In the early eighties, I invested in an ALLtest tool. Within a day, it fingered a car with a defective alternator, even though nothing showed as being wrong. A bad diode. Back then most cars still had points. The Alltest would flag a distributor that had worn lobes (dwell variance). You can often take an old PC and convert it to a testing tool with some interfaces. Then you can test under load. Exhaust gas analyzers can often be found cheap.

Great channel and maybe Vinny is the future apprentice???? He’s a good dog

It’s almost always in the tune of the carb!

NICE!!.. That was EXACTLY what. well, if you go back and look into my comments from before you'll see that I EXACTLY did not say it was what you just figured out that it was what it was.. AND I actually didn't even post anything in the comments.. LOL.. just messing around.. but.. I do like watching your videos.. I have an '86 Honda XR250R, '03 Honda XR250R and my sons '14 CRF125FB which he already outgrew last year. I bought it over 5 years ago for $750.. NO JOKE.. the kid (17) was just tired of it and also outgrew it. I spent around $400 on brand new parts from Babbitt (If memory serves me right) and replaced all the bad i.e. Kick, both pegs, handlebar, seat, key switch etc. Ran through the wiring and made repairs. Now, I see these bikes are selling for over $2K.. niiiiccceeee!!.. LOL.. The company that worked on my '03 took so long in fixing it, they're giving me a '76 Honda street bike but no title. The original owner didn't want to pay $1500 to fix it...but I'll sure take it.. lol.. I think it's a prelude to the Goldwings model.. I'll find out more next week.. AND.. I'll start working more on them myself.. thanks to YOU!!.. Great content!!.. CHEERS!!!

I agree with the mid carb leak comment. Seen this many times. And you should learn to test your coils. A resistance qnd ohm reading can tell you a lot. The carb was never ment to be taken all the way apart. I did fix one ounce by making a gasket from a bicycle fat tire inner tube. But I didn't fix the other ones when I tried. Good luck man.

I wonder if the previous owner had jetted it as a 450, and not a 400?

Did you put the needle back to what it was when you changed the jetting

Seems like a coil pack when it gets hot cutting out

Your 1st video indicated fuel leaking out of carb after sitting for 5 minutes. That is a sign of float level issues and/or needle seat gas flow valve not seating properly. This will make an engine run rich as you have found from Plug inspection, by Main re-jetting carb down, & raising clip lowering needle from OEM position. From looks of "Lay of the Land" around your test area, I would think you are at or near Sea-Level. This would make me suspect of "Carb having been Rebuilt" by PO, having been done properly or just float level/needle seat issues. The carb also has the aftermarket Power Now Blade from Scary Fast. I have this on my 02' 400RFS MXC along with the Accelerator pump bowl. My bike uses same carb and runs great with Stock 175 main jet. Your bike does have either aftermarket header or the later exhaust header, as all 02' 400RFS motors had the twin header. Enduro Engineering had a lot of aftermarket goodies for these bikes.

What a deal. I'd buy that for a dollar well 1300 of them. You did have to fix it but your efforts paid off. Take care

It's definitely better but still not right. Somebody is gonna get a lemon lol.

They have realy good mottors so probaly not that but are known for wireing probaly cdi or stator

It sounds better smoother now ... I hope you made a good profit on this one ...

I still don't think it's fixed even tho it's running better if it was fixed that low end stumble wouldn't exist plus ur now running smaller then stock jetting and that should never be the case

Your Meter will NOT give a true reading whilst you have that darn beeper running .

Experience talking here. I had a 2002 KTM 300 for 4 years. I know. It's jetting. The KTM is very finicky that year. I could tell the difference in the bike in a simple change of elevation. I can hear the engine is still rich in the elevation of the needle jet. Raise the clip in the notch 1 or 2 levels & that thing will rip. Eliminate the hesitation. Leave all the other jets alone. I even created a data base of which combination worked best at which elevation. KTMtalk will help you too with step by step, pictured, numbered instructions. Good Luck! 👍

Try pick up coillum maybe or jetting bikes in nice shape

1) You say, you've been through carb 4 times? 2) Have you been doing this on the bike or tearing down carb absolutely to body, verifying all orifices, passages Circuits & Float Level? 3) If you went that far DOWN from 172 on the main jet from stock to get engine to clear out, You, still have an issue, 175 is stock. 4) You need to verify existing jets for not having been drilled or resized. 5) Accelerator pump rod needs the rubber bellows boot to keep dirt/H20/debris etc. out of rod actuator accel pump system. 5) Idle sounds way high also....Where is the mixture screw set? Carb Specs per Haynes KTM-RFS (Racing Four Stroke) SOHC 00'-07'. Haven't compared for accuracy, to my 2002 KTM Factory Manual. 2002 KTM 400 RFS (Racing Four Stroke) EXC Keihin CR-39: Mixture screw base setting = 1 turn out (400 EXC, MXC, SX, 520 SX) Main Jet = 175, Main Air Jet = 200, Idle Jet = 48, Idle Air Jet = 100 Starter Jet = 85 Jet Needle = OBDTM Needle Position (all 400 RFS) 4th from top Idle Speed 1400-1500 RPM

Love your videos by the way

Hit frame with a hammer simulating vibration as you checking with ohms also

The previous owner may have had it jetted for a 450 since they thought it was a 450. That may have been the issue

Carb mid-body seals.

Officer: "Do you really need to ride on the road?" You can also do plug chops without any traffic......

32:59 ... before you mess with the main jet again why don't you move the needle clip down to where it was before?

why would it rev out just fine in neutral if the issue was just incorrect jet? Why was the issue not present in neutral?

Yet another great video keep it up

Joe you need to try and find a Honda trx 700xx that would be Awsome to see

Ho Lee Chit. That was tough.

What about that pipe thats on it? Isn't it supposed to be a twin pipe outta the engine? On them EXC 400?

why is it idling so high due?

@kincadepavic you think this will happen to the yz300 ?

Good york Joe.

Good spark try leaning it out Just noticed you can tell that motor hasnt been apart they build good motors

I liked how you used black and white

Did you ever solve the problem with the yellow Honda 400ex that you posted about two months ago?

Make it like the Grant Langstons factory look bike, they are awesome

Yep idling high so not quite there yet

I haven’t finished the video but my jaw dropped after lowering the needle didn’t work! I felt the disappointment!!! 🤣

I have the mxc version of this bike. Same year.

That’s beautiful land you get to ride on.

Again with the fast click my finger locked up

Put a headlight on it tail light it would be nice on off bike