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Came across this 1 hr 44 min long video of Stan Lipert re-assembling an RD400 motor with little explanatory prompts throughout, including him designing and fabbing his own chambers!  Super valuable resource!

The last few times I've pulled the oil line hose off the carb, the whole nozzle comes out as well, which worries me it might wiggle itself out while riding (and no oil --> bad day). I can likely mess with the brass press fitting piece on the nozzle to expand it a bit (or get new nozzles), but wondering if a more permanent solution might be to just drill/tap the injector hole and use a threaded brass barb fitting instead.  Can't think of a risk other than it leaking or vibrating out, but if done right with a suitable gasket/crush washer and loctited, seems it'd work just fine.  But if this was a better solution, imagine the wise engineers at Mikuni would've already done this. Any issues I'm not thinking of?

What happens when you throw a Hayabusa engine in a tiny Fiat 500?

Do 2x Uni Pods flow more air than a 2-into-1 K&N? Enough to require up-jetting the pilots/mains?

I've had this bike for over 5, and it runs and is fun to ride, but I don't think it's running quite like it should.  I've had the top end done by Chuck, installed a Vape, boost bottle, etc, but still not running primo.  So I can only conclude it's my inability to tune the thing properly or sync the carbs properly that's the problem.  This being my first and only 2 stroke, I don't have the experience to know what it is supposed to feel like or sound like.

And so I turn to 2sw for help.  I recorded a video of the bike running and my efforts to sync the carbs as explained in my Haynes manual.  I'm hoping that someone here can watch and say "your problem is that you did X, you should be doing Y" or "if you listen at 2:02, you can tell it's running rich/lean" or point out something else I'm doing wrong that'll help me get the bike dialed in.

Setup:

• RD400C
• Chuck stage 1 with TSR boost bottle
• Dave F mod w brass ball removed, airjet drilled to 2mm
• Vape ignition @ 1.9 BTDC
• Main: 200
• Pilot: 35
• Needle Jet: P2
• Need: clip at 2nd position from the top
• Air screw: 1.25
• Slide: stock, synced so the bottom of the "dot" as viewable through the hole on the carb body is align to the bottom of the view hole at full throttle

I think my RD has sparked a love for all things that are impractical money pits, and I've become increasingly obsessed with the idea of getting an old clunky, uncomfortable, overpriced, CO2-spewing cage - specifically a 70s era SUV like a Int'l Scout, Land Cruiser, FJ40, LR Defender or Bronco.  I'm undecided whether I want to be talked out of it or encouraged. 

Anyone else have a 4-wheel obsession they're dreaming about or gave in to?

Replacing the front fender that the PO installed (which looks too chunky and I think is for a CB or some other larger bike) with a new Airtech one to keep the weight down.
(1) What's a good clearance between the tire and the fender? I've read anything between 3mm and 1", but figure 1/4-1/2" would give enough buffer for tire expansion and for pebbles that might get stuck in the treads.  Prefer to keep the clearance on the smaller side bc, you know, it looks cool. Any recs?
(2) Since a fiberglass fender doesn't provide the structural stability of the stock metal fender, is it recommended/necessary to use a fork brace to keep the forks from twisting?  Keep in mind this is a street bike, and I also plan to add a stabilizer, but watching too many tank slapper videos on youtube has me paranoid.

[(what is the difference between this and 'Emulator Valves' below?)]

I'm sending my front forks off to Race Tech to be rebuilt, and was wondering what options are typical/recommended for a street RD400.  Also, are preload adjusters recommended? Doesn't look like Race Tech offers them. From their service request form, here are the different options (red=options I think I should select; orange=options I'm not sure about):

Comp Gold Valves [YES / NO] (what is the difference between this and 'Emulator Valves' below?)
Reb. Gold Valves [YES / NO]
Reb. Holder KYB (Must AX/SX) [YES / NO]
Emulator Valves [YES / NO]
Springs [YES / NO / If Required]
Pressure Springs [YES / NO] (what is difference between "Springs" and "Pressure Springs"?)
Seals [YES / NO / If Required]
Bushings [YES / NO / If Required]
Hole Shot Device [YES / NO]
RT G2-R Cartridge [YES / NO Length+____]
RT G2-R Cartridge caps [YES / NO]
Lower [YES / NO -____mm(@wheel)]

Re-doing my throttle cable using the Venhill custom cable kit (OEM is too long with clubman bars), but having trouble locating a 3-way throttle cable splitter box/junction to work with the 2 carbs + oil pump. Seems my options are:
1) find a 3-way splitter
2) use a 4-way splitter (with only 3 of the splits being utilized)
3) modify the OEM splitter

Option #1 would be the easiest, but I can't seem to find any except for an Amal 244/2080 splitter https://steadfastcycles.com/products/copy-of-junction-box-splitter-triumph-norton-bsa-amal-throttle-cable-union-244-104-1-2 - maybe that will work?

Option #2 is easier to find, but not sure if using just 3 of the slots would cause splitter to pull the cables unevenly.

Option #3 may work but I haven't opened it up yet so can't tell.  Looks like it's held together with some rivets, so would have to grind these off then figure out how to re-attach it after I make the new cables.

Has anyone had to do this before and have some ideas?

...what would you buy?  Spend it all on one higher end piece of equipment? Get a few small, cheap Amazon specials from China (drill press, bench grinder, etc)? Extensive set of hand tools?  Let's say you'll mainly be using it for, I don't know, say, restoring an old motorcycle.

Anyone use or have used work gloves for riding gloves?  Yes, I know that $300 moto specific gloves with all the high tech armor is better, but I'm curious whether people think a work glove could be passable or have used em themselves.  I have a moto-specific summer glove and a heavy winter glove, so was looking for something to use in transition seasons, which took me down a rabbit hole. Looked at the Lee Parks Designs elkskin gloves, then the Aerostich versions. Then read that Aerostich was made by a company Geier so looked at those. Then just started looking at driver/roper gloves generally and came across these $15 leather kevlar-ish lined gloves from Galeton: https://www.galeton.com/rough-rider-reg-cut-resistant-leather-driver-gloves/2506-product/ and the upgraded version with knuckle protection for $24 https://www.galeton.com/rough-rider-reg-flakbak-trade-cr-impact-protection-and-cut-resistant-leather-driver-gloves/2514-product/

Have my new Vape all hooked up and working 

I have it hooked up via the relay so the stock switches work.  That's all working fine, but the one thing I can't figure out is how to get the neutral light working again.

I made a new wire and screwed it into the neutral plate (see photo), and ran the wire behind the vape, through the grommet hole and back towards the fuse box.

On the other end, I put in a bullet connector and connected it to sky blue wire (see photo) that the original neutral wire was connected to.  I thought this would do the trick, but no luck.  What am I missing here?

I'll be installing my new Vape ignition over the next few days (merry christmas to me!) and was reading through the instructions in preparation.

The instructions at one point say "Do not use spark plugs with an intern suppression resistor. NGK (e.g.) offered such spark plugs coded with an "R" (for resistor)".  Seems pretty clear. 

But, later on, it says "You should have received the HT Cable with the fixed rubber cap (which does not contain a resistor) as a part of the kit, you should have to use a spark plug with an inbuilt resistor (or replace the cap with the one containing a resistor) to comply with your local laws (Electromagnetic compatibility requirements)".  Hmm  so does that mean I should use a resister plug?

Then later, it says "Do not use a spark plug cap(s) containing a resistor WITH a spark plug(s) containing a resistor at the same time", which seems to imply it's ok to use a resistor plug as long as I don't also have a resistor in the plug boot (which I suppose would only be the case if I were to ditch the Vape-supplied plug boots and use my own, which I am not doing).

So, resistor or no resistor spark plugs?

If no resistor, any suggestions on brands, since those B8ES NGKs are a scarce commodity these days?

I recently installed some Trail Tech CHT gauges (with mount designs shamelessly ripped off from 1976RD400C's bike) to give me an objective measure of what's going on in my engine since I don't have the experience to know from feel/sound.  The left cylinder seems to be running about 30-40 degrees cooler than the right (keep in mind this is city riding, so no long straights).  Replaced the plug today and the old one was a bit oily/black. New plug runs better, but still seems like it's 4-stroking and still running colder.

Any ideas about what would cause this? Haven't had a chance to troubleshoot yet, but things that come to mind are timing, coil, ignition system generally. Battery is a Yuasa with less than 7 months on it.

Carb setup: Dave F mod, 200 main, 40 pilot, 5DP7 needle in middle

https://www.facebook.com/classic2strokes/videos/2362366170642017/UzpfSTEwMDAwNTg3NDY2MDkxMjpWSzoxNjUxMjcyNDMxNjk0MjE5/

Anyone know what this grey thingy on the bottom of the triple tree is? Thinking it might be a steering damper but haven't seen one like that before.  Funny how years after owning this bike I've never noticed it before.

I was double checking my timing, and I noticed that the timing differed depending on whether I was turning the crank using a wrench and turning the stator bolt or pushing the kick starter.

Using the stator bolt, it was just a bit off 2.0 BTDC. Using kickstart it was about 1.7 BTDC. That seems like a not insignificant difference. I did not touch the timing plate at all in between the two checks. Note that I'm using the Vintage Smoke Dyna.

Why is that the case? Which method is the proper one for setting the timing?

See video (you have to listen for the 'snap' of the spark):

Also, just before this video I checked using the stator bolt and it was almost bang on 2.0. 1 min later, without touching the timing plate, again checking w the stator bolt, it moved to ~1.92. How in the world did it move without touching anything?

Now that I got my RD400 running again, of course I had to do something stupid to screw it up.

On the right side carb, one of the float bowl screw holes was stripped so the screw wasn't tightening fully. Drilled and re-tapped for one size larger to "fix" it.  Then thought I might as well do all the screw holes so the same size screw is used.  Tried testing it and fuel spilled everywhere.  I must've drilled/tapped one or more of the holes crooked, because now the gasket surface of the carb is warped, making it impossible to get a seal on the float bowl - see photo.

Anything I can do to fix this, or did this screw fix screw me? Even if I managed to straighten out the carb again, I'd probably have to drill/tap even larger, and not sure there's enough clearance.

If it's ruined beyond repair, can I run them with the left OEM and the right a new replacement? Or will they not 'match'?

FYI I'm running stock carbs, Dave F modded.

Not sure how much time has passed. All I know is that last time I rode this thing I had a different girlfriend and lived in a different apartment, so it's been 2-3 years. BUT, finally got this thing running! Now time to get it dialed in right. Here's what she sounds like:

https://youtu.be/q7XCDO-jln4

I took it for a quick spin around the block, maybe 4-5 minutes (cut it short after I passed a group of cops who all turned my way a little too curiously). Ran ok. Not "wheelie" good, but picked up speed pretty quickly. But as I was finishing up, it lost power and wanted to stall unless I kept the throttle cracked.

I had the top end done by chuck, stage 1 porting, with banshee intakes, TSR boost bottle, spacer. Stock carbs but w Dave f mod. Used the carb setup recommended by chuck (to start a bit rich): 210 main, 40 pilot, 169-P2 needle @ 4 (1 clip rich). airscrew 1.5 turns. Idle screw about 1.5 turns from just touching.

What do you guys think for jetting adjustments to get it in prime tune? Any ideas about the power loss? Any ideas why the left pipe isn't smoking as much (oil line is full all the way to the inlet nipple and was pumping fine when I tested).

I'm getting a lot of bubbles when priming the pump (I have the the throttle jammed so pump is on max). Middle line isn't pushing out any oil. Lines are on tight.

Video: https://photos.app.goo.gl/kyZs9gkDnwNFLvRq6

Is it time for a rebuild kit?