royb
Junior Member
Posts: 85 
|
Post by royb on May 25, 2017 3:12:56 GMT -5
Mine has been converted at some point in its life to a single carb, #45 Pilot jet, #130 Main, Z6 nozzle, 4N8 needle with clip on lowest (nearest needle end) point.........
Carbs are not my strong point.........so my question, as this is a single carb it obviously now needs to draw in enough fuel/air mixture, are there any Guru's out there could tell me if these sizes are correct/good starting point? Assume a #140 is larger? would that be the way to go? Trial & error?
cheers
Roy
|
|
|
|
Post by jayteenz on May 25, 2017 19:35:52 GMT -5
Hi Roy
Not my strong point either but I also belong to the Honda SOHC forum (http://forums.sohc4.net/) and they have a section for "Other Bikes". I suggest you ask the question there as there are some really knowledgeable carb people on that site.
Just be aware you may get some gentle ribbing about being the owner of a TX750 !
Cheers - JT
|
|
royb
Junior Member
Posts: 85
|
Post by royb on May 26, 2017 2:51:08 GMT -5
Thanks JT, I'll mention that I also own a CB750 K7 (not noticed that section on the site?)
|
|
|
|
Post by farmrjohn on May 27, 2017 9:36:59 GMT -5
How does it run now? That could give you ideas on what might need adjusting. For example, does it start and idle, stumble on acceleration, have issues at certain rpm ranges, not want to rev, popping exhaust when slowing while in gear, etc.
|
|
royb
Junior Member
Posts: 85
|
Post by royb on May 27, 2017 19:34:51 GMT -5
Blimey, give us a chance farmrjohn, hopefully soon.......waiting for a float & emulsion tube seals, then be nice to see if I can get it to start........
|
|
royb
Junior Member
Posts: 85
|
Post by royb on Aug 14, 2017 9:51:33 GMT -5
OK, the story so far......not found much info on the web ref single carb conversions, & trial & error (as I suspected) seems to be the way to go. It seems doubtful after all that work to convert that it ever ran properly (I've not had much success). Initially carb removed, cleaned, new seals/gaskets & diaphragm checked ok. Also fitted larger pilot jet (#50).
The first thing I found was the carb was fixed into the stub with 2 x screws & gasket sealant! I thought this was never going to work considering how many times the carb would need to be removed (a lot so far), so bought a piece of silicon tube (used on cars so thought it could cope with the heat) cut to length & seems to work ok. Next I needed to re-fabricate some supports for the carb (no airbox) as it had now moved back a bit so couldn't use the ones already made.
Anyway, eventually got it to start but it wouldn't run for long & was quite clattery. Re-checked points gap (new points fitted) & timing (which was a little out but not much). Then went onto cam chain tension (fine) & valve clearances - these were miles out so adjusted those & tried starting again......easier & quieter but still won't run for long (any throttle results in misfiring back through the carb & engine stopping). Also flooding too which was down to incorrect float height....now sorted.
Presently I have a #60 pilot jet & mixture screw out 4 x turns & it's running better (tickover with choke for about 10 mins, still won't run without choke but can give 'gentle' throttle now!) Feel like I'm heading in the right direction at least! Decided to go up to #80 pilot (on order) & see how that goes, once that's sorted, then I can look at the main jet.........
So far this has been an interesting (and frustrating) learning curve (even wondered about changing the carb for a round slide but decided I'd persevere for a bit longer!), so please feel free to chip in with any advice......Roy
|
|
|
|
|
|
Post by gonner on May 13, 2022 17:12:15 GMT -5
Pleased for you getting it sorted in the end.Those keihins are infinatley adjustable although takes plenty of plug checks to get em right. Put a pair on a CL350 and what a difference when set up.
|
|
