generally, i don't ride during jan-feb, so still looking forward to nice autumn rides.
and thanks for the link; let's see what/when i'll have to hone after this, but will consider dedicated tool for that.

i understand that life situation poses some challenges, but not sure your engine will understand.... your DIY hone might or might not work, we dont even know what grit you used, if it was emery cloth or plain sand paper and even if i knew, i could never tell if it'll work

in my 45 year of wrenching, I never did it by hand, neither heard about anyone doing it. draw your own conclusions

your motor, your choice.

By the way, if you use google translate on xtrock's link, you will even see the are noting all the paramters to reach good honing,

regretfully, that link goes up only to 60mm bore, youll need bigger than that of course


this ones are also cheap and adapt to any bore


https://www.youtube.com/watch?v=lSqgJh0Ed5o

Well i didnt link for him to buy here, it was for him to find correct tool for job, offcourse it will have to be correct size, you write like others are idiots here! You dont get the perfect cross honing with your link, cross honing is what machineshop use so ye buy it. https://www.mscdirect.co.uk/abrasive...ning-tools?p=2

well, indeed agree about the risks of not achieving needed finish.
but still had decided that this attempt at least would be better than leaving cylinder wall like it was - with the signs of glazing...
"tool" was plain sandpaper (320) along with the engine oil.
and i do realize that in the scenarios like this at some (increased) extent will have to rely on the crossed fingers..

well, meanwhile carbs arrived. as noted earlier, finally decided to try ones from raptor 660 (chinese copies).
first impression was about weight - 200grams more than original kit.
then, about cleanliness - just ok, not super-clean. no big deal since there's lots of studying / tuning times ahead, naturally involving cleanings as well.

Cant imagine you get any quality that will work over time for 35euros, let us know the fuel consumption, bet its not accurate. I was down to 0,34l 10km last trip with KN filter, fully exhaust Yoshi and stainless downpipes + dynojet kit. Good luck!

sounds you've got pretty nice kit on the both sides of the engine )
well, considering that during the last month or so bike consumes 0 fuel, feeling that any positive number will be better..
also, pardon me bringing maybe too much of subjective perspective, but for now this chinese kit is the best kit in the world for me, as it's only option to get the bike running again.
otherwise, if/when the future lets, still thinking to install normal ydis. it's one more reason for which i'm trying to keep the original airbox setup.

ok, some updates -
this new kit is 1.25cm shorter (filter-engine axis), so thinking to craft some aluminum adapter plate between engine and manifolds.
speaking of manifolds, using pair of right (bigger) intake manifolds of xt, one assigned on left with 180° flip.
also, as these carbs have shorter fitting ends towards the engine, had to cut 3mm from manifold lips. afterwards they join well.

on the airbox side, right (bigger) air duct fits. but had to modify left one - cut ~1cm on the carb side and with scalpel and sandpaper made more or less soft (curvy) transition inside.
then took raptor's air duct and cut ~4cm from it (also carb side).
afterwards fitted that cut part over xt's duct like sleeve.
appeared pretty tight. glued with gasket silicone.
offset is about 1 cm:


these carbs are taller and their both lower and higher ends are more bulky compared to xt's carbs. had to play with some cables to make the fitment easy.

main problem for now is the distance between diaphragm vent passages and bike frame. it's too close even without that adapter plate:


seems it's possible to cut some of their length.

in the case of raptor, these vents are connected to air ducts separately.
does this setup of raptor affect the diaphragm response?
what if i connect them to just the atmosphere with some sort of filter (like it's in xt's case)?

as for the adapters, you could also make them from nylon, its fuel resistant and a bit more forgiving to mount than aluminum.


for the vents, you just need a simple rubber elbow, and route from the 2 tubes to somewhere clean. the carb does not constantly suck air from there, its just to allow free movement of the slides, so a filter is nice but not a must, its more of a venting.


yes, they could be shortened too.



something like this for example (not sure if this is the exact size you need, but to get the idea)


https://www.amazon.com/Dorman-Help-4...ef_=ast_sto_dp


Hope it all works for you.

nylon sounds nice and lighter. easier to craft as well.
that elbow setup is clear. main thing is knowing that it's not necessary to connect these vents to air duct/airbox.
as for filters at the end, i don't think about dedicated mushroom filters, rather some simpler solution to block dust.
thanks for good infos!

long story short for now, carbs are installed and bike runs.

making adapter plate, finally decided to stick with aluminum, as melting temperature of nylon felt somehow as not on the "peace of mind" distance from possible surface temperatures of the engine run by carbs yet-to-adjusted..

used some gasket silicone to mate head and this plate.

for diaphragm vents used hoses already shaped with 90° corners, something like this -


cables. was lucky to find flexible steel tube with 6mm outer diameter.
cut threads, bent and pressed into the carb body. smaller (more bent) is for choke.


more photos and complete story later, when jets, needles etc. will be finally chosen/adjusted.

having these questions for now:

1. what if using smaller hoses for diaphragm vents (attaching them by pressing inside the steel tubes on the body, rather putting from the outside)? will this reduction of diameter affect how diaphragms will work?

2. needle jets had this cylindrical rings attached, supported by jets:

these rings have 4 holes on the sides and reach almost till the bottom of the bowl.
problem is that in the jet kit i've got all main jets have the base (where screwdriver goes) bigger than inner diameter of this ring. so had to take these ring away and attach jets directly to the needle jets. btw, just like in the case of original carbs.
what it the function of this ring? maybe it worth to find jets with smaller base to let these rings make their sense?

nice!


HOW does it run then?



1. as long as you have 2-3 mm free internal diameter, i think the tubes will be fine.


you can try riding the bike with them disconnected for a few minutes, nothing will happen, then put the tubes on and see if they make a negative impact on riding. again, they are just vents to atmosphere to balance pressure



2. guess those jet protectors are for ATV to maintain fuel around when off roading.... i would say not a problem to remove. again, you are on your own here, see how it works with/without



compliments on the persistence!

turboguzzi, thanks for the answers etc.

good thing is that bike starts easily, generally feels bit more powerful, compared not only to the last days of previous carbs.

things to solve for now are rich-ish mixture (overall) and possible lug/delay which could happen somewhere between 25-40% of throttle opening. currently manipulating with needle positions.
temperature keeps changing here pretty sharp day after day these times and feedback seems complicated.
hopefully will manage to test exhaust with the mixture gauge.

maybe before worrying about that jet protectors, will consider to check fuel level in the bowls. thing is that these carbs now are somehow inclined forward compared to their intended use (raptor), maybe 15-20°.

smaller diameter vent hoses could make removal/installation times bit easy. yes, it's still pretty hard process (especially installation), so every cubic cm of saved space matters a lot...

sounds like your jetting is close,
the 1st thing that you have to find is the main jet, leave the needles in original place and just try +/- 5 in the mains, find what works best,


only then move to needle height (if still needed)
these carbs can work ok with +/- 10 r even 15 degrees of tilt, so dont touch their fuel level for now. easy to mess that up

thanks again for a good advices, turboguzzi.
good to know that carbs are ok in the given setup.
let's see by which jetting i'll end up with...

hi everyone
after >3000 kms with new carbs, seems it's already a time to share details and feedback.
on my high-mileage '02 xt600e, original (ydis) carbs became worn and damaged beyond repairability.
considering suggestions by more experienced members, prices, availability and so on, decided to replace damaged carbs with the ones from 660 raptor. although, bought not an oem kit but a chinese clone.
part of the plan was to keep the original airbox on my bike.
let's have a look on general diagram of raptor's carbs:


to compare air ducts and engine intake of xt and raptor, they're more or less the same.
on xt "left channel" (air duct & carb intake - carb output & intake manifold lip) is smaller, compared to the "right channel" (all these members are with bigger diameter).
raptor has (almost) symmetrical channels, with the sizes equal to xt's right, bigger channel.

now differences.

maybe the main point to consider (at least in my personal opinion) is how these carbs work: while xt's ydis setup is somehow a complex (but still nice) combination of slide and cv carbs, raptor has almost identical 2 cv carbs just joined together.
throttle: xt has dual cable setup, while raptor is run by single.
choke: xt (at least my generation) had a pull lever immediately on the carb body, while in the raptor's case it's cable operated.
hoses, vents etc.: raptor's carbs have them a few more and fuel delivery pipe is also with a bigger diameter (8mm as i recall).
dimensions: raptor's kit is heavier, overly taller and wider but shorter (longitudinally, along with intake axis) by 12mm.
partially this shortness is caused by where the intake manifold mating grooves start on raptor's carbs: they start ~3mm closer to the main body, resulting a shorter output lengths, i.e. these carbs don't go into the intake manifolds as deep as xt's carbs.

according to all these differences, here're the lists of modifications on bike and carbs separately.

mods on the bike:

• adapter plate, to compensate length - 10mm aluminum between the engine head and intake manifolds. basically, it needs two 30mm holes at the distance of 30 mm, with four 7mm holes for the bolts. plate is glued to the engine head with gasket silicone. in theory, the 8mm plate might also work, making removal/installation of carbs a bit easier but it may stretch air ducts more and create some risk of leak.
  
  
• intake manifolds: raptor has asymmetric ports and moreover, manifolds are angled much more, but xt's manifolds work in this way - left one is not useful, instead another right (with bigger diameter) piece is needed. also, since these carbs don't go into the manifolds as deep as the original ydis, manifolds must be shortened - 3mm of the length is cut from the side of the carbs. there's still enough width left for proper band clips. for easier fit, a small (~1mm) tapered slope is cut inside manifold lips.
• air ducts: right one is suitable, left is again small. one option could be to replace it with another right duct, but due to current crazy prices for this part, bought raptor's air duct instead and cut the final few cm on it (carb side). then shortened (~10mm) xt's duct and combined (again silicone) it with the cut part from raptor's duct. luckily, that part from raptor's duct fits perfectly over xt's duct like a sleeve, and considering where to cut, it's possible to achieve a pretty smooth transition between these two rubbers.
  
  
• throttle: one cable gets removed, assigned for the choke later.
• choke: found handlebar lever of some quad bike. it appeared pretty easy to attach below the left switch assembly with two screws and also easy to reach and operate by thumb.
  
  

mods on the carbs:

• steel tubes of diaphragm vents: they were almost touching the frame, so had to shorten both, now about 8mm is left. attached rubber hoses are with 90° bend immediately at the beginning to go away from the frame. ends of the vents are covered by pieces of breathable textile (yellow ones on the photos below) to make a dust barrier.
• cover plate (#15 on the diagram): had to remove it, as it was making installing the carbs almost impossible.
• main jet protectors (#23): removed them also, just because of the jet kit i had - heads were bigger and not fitting inside those rings.
• cable guides: these new carbs came with 2 of them, but their shape was not suitable. and they were pretty hard to bend properly, so found some softer steel tube, cut 6x1mm thread, bent as needed and pressed instead of old ones. one with 90° bend is for choke. long nuts are useful to adjust free play of cables.
  
• idle mixture adjustment screws: when carbs are installed, it's nearly impossible to reach and adjust the one on the right. the only way seems to be the combination of good light, tiny concave mirror with a long handle and a small flat screwdriver bit attached to the gimbal ratchet. but even this wouldn't work if i had bit thicker fingers (and the engine hot enough). so special screws with long handles are highly recommended. the ones i've ordered later came without markings. markings are important not only for obvious reason but to be able to check that they don't move.
  
  despite that these new screws came with stronger springs, i've made them a bit lighter by drilling their levers and after installation they're bound with a rubber in ∞ pattern.
  

installation procedures:

removal/installing carbs on this bike has never been easy, especially with some earlier modifications around.
now with these generally bigger carbs, more hoses (and more about to come after waterproofing with t-joints) and cable guides pointing outside, it's a real challenge. after lots of wrestling in the past and now, i found this way best:


move the airbox as further back as possible, remove the ignition coil, lift or disconnect cables around, detach and lower the rear brake fluid container and remove the right intake manifold, then take carbs out from the right side. when assembling, carbs go back from the same side. first i make sure that both air ducts fit well, then, while the airbox is still back, stick in right intake manifold and tighten the bolts. then it's time to push airbox&carbs forward, twist carbs back and forth until they will go all the way into the manifolds.
in this easy-to-write/read turmoil, every step making the process even slightly easier matters a lot - like each free cubic cm, lubed lips, all band clips in proper positions etc. etc..
although, along with all these dark stuff there's at least one noteworthy benefit: both needles are adjustable without the removal of the carbs, just considering that uncapped carbs don't collect any dust from the frame or cables around.
that's how installed carbs look like from the sides:




when making cable adapters, another important point to consider is that space around them is pretty cramped by the body of the carbs itself, engine and fuel tap:


now about jetting.
current conditions are following:
oem airbox without snorkel, k&n washable air filter; oem headers with straight aftermarket muffler.
80% of riding is happening at 0-10°c (dry climate), and at 400-1000m altitude.
idle screw is about 3 turns in after touching the plate, rising butterflies maybe 1mm.
idle jets are unchanged, #22.5.
idle mixture screws are at 2.25 turns out.
starter jet (for choke) is #80.
main jets are #140.
jet needles have 6 steps and they're in the second position from below, i.e. raised almost all the way up.

summary and conclusions:
with this setup, the bike starts easily and feels a bit more powerful. fuel consumption is either the same (5.5l/100km) or slightly more.
throttle response is not linear, feels more steep in the beginning and if the throttle is squeezed fast enough, could transform into the step (somewhere around 1/4 of opening). this could happen at sharp deceleration as well, so the solution for now is softening this step with slight clutch input. maybe this is solvable with better tuning.
the only actual problem i had with these cheap carbs is seemingly the shaft moving throttle butterflies could develop some friction-like resistance above 75% of throttle opening (where there's least movement statistically). it still moves but with some unsmooth feelings. cleaning the carbs from inside/outside solves this problem, but it could appear after 1000 or so kms. anyways, will have a closer look on next removal, maybe will attempt to split the carbs as well. only clue for now is that despite being behind the engine, since that protector plate (#15) is removed, the shaft mechanism is more exposed...
generally, i'm pretty happy with this conversion. after ordering these carbs and before actually trying them, i was thinking about them as more or less temporary solution, with a mindset to keep an eye on the web to find some decent original ydis carbs. for now it's changed and seems i'll be happy keeping them as far as they'll be happy doing their job )

of course, i'd like to thank all the forum members helping and supporting me along the way with their advices, infos and ideas, together with people making this forum possible.

p.s. some random fun before and after )