FUBAR's Build

yeah i hear ya. took the plugs out and see them sparking when i ground the plug body to the engine. so im pretty sure i have good spark. tried switching the cam timing units wires to the tci box to make sure they werent backwards.

(im pretty sure this is the same as switching the plug wires, it would just be sparking 180 out or whatever) still nothing.

does the clutch have any impact on starting procedures? before i didnt have it hooked up at all. it is in neutral when i crank it.

.. also discovered a side problem regarding the k-start. it didnt seem to engage at all before( not even near the bottom)

but now when i tip the bike over far to the clutch side and move the k-start, it catches and i feel compression and the motor turning. im wondering if i forgot a spring or somthing in there to put pressure on the worm gear.

on a side note, those aftermarket brake/ clutch setup i ordered off ebay work great. locks up the front disk really well.

anyways here just a picture of me goofin' off, seeing how it might feel when im done.

DSC00736.jpg
 
there is a spring in there, it also acts on a toothed pawl to engage the kick drive.

All I can think of at this juncture if you've put some fuel down the bores and tried that?

swap spark wires round?
 
the spark isnt bright bright blue but its there and seems consistant. even stuck a test light in the boot and turned it over and it flickers.

i just tore apart the carbs. everything looked ok. the diaphrams look a bit more shriveled then they did the last time, i may have gotten a bit of carb cleaner on them. but no holes. and the needle piston (?) still drops slowly in both.

on thing to note is on one main jet there was a brass washer, the other side didnt have one. my jets are 135s and 42.5s with pods and long baffled 2 into 1.

air mix screws are at 1.5 out but have tried everything inbetween.
on the TCI large harness plug i have power on 3 wires - red/whitestripe, grey and orange.
i tried swapping the plug wires. but now my batterys acting funny. maybe because its on its side and a vented batt. i may try a new enclosed type of the same size and try again.

i did add a bit of oil since the last start to the case, but i doubt that changed anything. no signs of gas in the case. maybe ill get some new plugs also.

on a side note i ened up ordering that denim jacket from revzilla.com
cortech DSX in dark blue
http://www.revzilla.com/product/cortech-dsx-denim-jacket

and i did get my aftermarket ebay brake bled and it works great, seems pretty easy to compress my forks though. i just rebuilt them and filled with the correct amount of ATF, ohwell

thanks for the help and ideas guys
 
ok got it running again, it was being starved of fuel from not venting the gas bottle i think. its idling good now without choke because i re cleaned the carbs thinking that was the problem.

tried to take it for a spin but cant seem to get it into gear, clutch cable is pretty stretched out and maybe that kickstart not engaging is affecting it. so i shall conquer that issue later, but for now im happy it starts well. thanks for the help.

also need a throttle cable with more play because it doesnt allow the throttle lever to lower all the way and it revs way high.

is there a idle speed screw on here somewhere or just the air mixture screws?
 
The idle speed screw should be right in between the carbs. Pushes up against the throttle junction. Some carbs have it up at the front near the cylinders, others have it in the back. Just look for a big spring-loaded screw.
 
ah yes i know the one you speak of that makes sense now. do the xs400s have a pretty slow chuggy idle or more pop pop pop like a normal twin. i dont have a tach so im guessing set it al low as it'll go without dieing?
 
If you want to use math, you can take your 1250 RPM and use gear ratios to find out how fast your bike would be going at idle with the clutch out. When you want to set it, lift your back tire and let the bike coast at idle with the clutch out in 1st gear. Let me show you what I mean:
1250 RPM at idle
x 2.5:1 in first gear
x 3:1 rear:front sprocket (not sure what the actual ratio is)
x 6.28*radius of wheel + tire (be exact)
so that will give you your speed in inches/min, convert it to kph and youll have your speedo reading to tune your idle with
 
JARichmond said:
If you want to use math, you can take your 1250 RPM and use gear ratios to find out how fast your bike would be going at idle with the clutch out. When you want to set it, lift your back tire and let the bike coast at idle with the clutch out in 1st gear. Let me show you what I mean:
1250 RPM at idle
x 2.5:1 in first gear
x 3:1 rear:front sprocket (not sure what the actual ratio is)
x 6.28*radius of wheel + tire (be exact)
so that will give you your speed in inches/min, convert it to kph and youll have your speedo reading to tune your idle with
Click to expand...

ah i see what you mean, i wasnt talking for tuning the speedo purposes, i was just speaking in terms of how the idle should be. i have no speedo or tach , but thanks ill use that in the future :thumbsup:
 
Glad you got 'er going again. Always the little stuff. Anyway, set your idle as low as you can, then raise it up so it sounds 30% faster. That's what I would do anyway. I would set it a little faster than you had it in your last video. If you have a timing light with a tach, you can use it to set your idle.
 
little update, got the bike running like a top, didnt seem to need a rejet but who knows when i start riding if it will bog at all. i slightly baffled the pipes and its got pods so im not sure.

got a new '73 petcock off a ebay
got the chain noises and rear tire alignment all figured out
i started a sheet metal headlight cowl but scrapped it cause it didnt flow right, im going to make a fiber glass roundy one in the future

theres a " garage built classics" show coming up june 24 in edmonton alberta if anyone is in the area, hopefully ill get the bike done in time


heres my headlight cowl inspiration:

coolxs3.jpg

coolxs2.jpg

coolxs.jpg
 
thanks BR


finally got around to making a shorter clutch cable, it seems to work well, i click it into first and it grabs nicely and lurches forward a bit.
took it for a very slow put down the alley in 1st w/out the twist throttle hooked up just used the carb throttle.

its evident ill need a chain tensioner and all the bolts tighetened up and loctite'd
but it was good to actually see it moving
 
Just an fyi, I'm running 2-1 with a straight thru "muffler" ad in no silencer, real short. And pods.

Main 137.5
Pilot 45
Needle middle clip
 

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