newbie carb question

Hi was wondering how you can tell if you have a yics engine or not?
if i use colourtune to set the plugs burning correctly do i have to sync the carbs after??

take it the mixing screw is on the top of the carb near the 3 sync screws.

cheers

 

Hi there, yes those are the right screws, but they only set the pilot mix, i.e. only from idle through the first 1/4 of throttle, from there the mix is controled by your needle jet. colour tune only sets the mix at the rpm you choose to use it at (and most folks use idle)

you don't have to sinc after. syncronising the carbs means you set them so the throttles on all four open at precisely the same time.
playing with the mix screws wont hurt this.

But sync'ing the carbs never hurts!

the best way to have them tuned is to have a dyno set up.

carbs are a huge thing to understand, and judging by the amount of posts about them, I think it's time a comprehensive guide was written....

Stay tuned.

 

cheers i was just wondering as it doesnt seem to be burning correctly as the odd one is black and the other is burning lean. altering these screws will it get them burning correctly.. my plugs are burning all differnet so hopefully this will sort it or do you think it will need new needles??

 

Wow, you have got some issues there. like I say these screws only affect the first 1/4 of throttle openning so you can only adjust the settings at idle.

Do you know if you have any airleaks from the inlet or airbox boots?

Have you cleaned your carbs yet?

This is quite an in depth problem you have here as all carbs seem to be doing things seperatley.

To give me more of an idea, could you clean your plugs, go find an empty road ride up to say 4,500 rpm in any gear from 3rd up. hold there for a few seconds, whip the clutch in and kill the engine.
pull over to the side, let the bike cool and pull the plugs. Take a clear photo of them exactly as they come out then shove 'em back in and continue your ride. This photo should give an idea of whats happening at typical engine speeds.

Personally I think you need to start with the basics and get those carbs whipped off and cleaned.

If someone could post up the link to the carb cleaning guide please????

(I can't find it )

After a good clean and thorough checkover, you need to return all carbs to the base settings defined in the manual for your particular model and see where you go from there.

You haven't mentioned what model you have or if you are running an airbox or pods.

If you can give as much info as possible (and pics) I am sure the forum could help solve your woes.

:lol: :lol: :lol:

 

yes,to fine tune pre-set them all 2 1/2 or 3.0 turns out
(depending on your altitude).
then check each one at idle.
turn the pilot screws accordenly and only a little at a
time. the passages are small and little adjustments make big
diffs.

 

sorry im running pods i got the bike with them already on its a xj650 maxim
after the bike has been on a run it has a strong smell of petrol it seems to run fine and there is plenty of pull but it does seem to sort of splutters a little then calms down in all the gears.

i will try what you suggest will be hard as it doesnt have its original clocks or a rev counter so will be guess work... im sure it will be sorted but i feel will take time..

 

hey just hold the throttle steady for a couple of secs. that'll do.

I just want to see a pic of whats happening....

Carbs are funny funny things, and will do different hings at different throttle openings.

A smell of petrol suggests something is waaaaaay rich somewhere!

If you can get that pic then we can get an idea of whats going on.

Running pods makes the carbs harder to tune, but it can be done with patience!!!!

in the mean time, have a read of this

carb theory

might give you an idea of whats going on!!!!!

 

cheers will post some tomorrow would it be ok to send directly to you or wold it be best to post on here

 

Put them right here, let the forum see. There is some pretty experienced guys on here that can give great advice!

 

Dont know if you can view the pics as i have no clue how to add pics

but if you can't see them i only ran the bike for about 2 mins and 2 of the plugs where really sooty and the other 2 was ok. im wondering if the previous person has messed about with the mixture screw of the bike??

 

^^ Either I need glasses or you need to learn how to use your camera. :lol:

Look on your camera for a symbol like this:



It'll set the camera into a close-up macro for shooting up close and personal.

 

By the looks of your pics (they are kinda out of focus!) it looks like you have 2 running fine and 2 rich

It certainly wouldn't hurt to return all screws to their stock position and try again.

 

lol no the camera is a shit one...it doesnt have that symbol on it..i will return everything back to standard and see how it goes...

will report back if i need more info..

 

By all means if you have a color tune plug use it!
If you have to set any particular carb much different than the others, then you will need to address the problem. On an older bike it is worth at the very least cleaning out the bowls and checking the float levels.

By memory it is only recommended to use the colortune plugs for idle mixture only.

Are your problems at idle, or through the entire RPM range?

 

With those Pods on the Bike; you'll likely have some difficulty getting the Bike ... "Tuned-up" without sacrificing some performance due to one factor or another.

Let me direct your attention to the Members who have fabricated "Intake Manifolds" from PVC Tube and Fittings.

Doing so, helps reduce the Total Volume of Intake Air, ... necessary to combat the Lean Condition you may face when you begin Fine Tuning in earnest.

 

i think the problem is through the entire range. the top end performance is also effected it will do 80mph no problem but it struggles to go any faster.. im happy with 80mph just need it to burn better..

 

You are deffinetaly struggling here, you should be pulling a lot faster than 80mph. My XJ600 is good for about 125mph showing on the clocks.

I think you need to get your carbs out and give 'em a good clean, using an airline to check all the jets. Check absolutely everything, check the diaphrams for cracking or tears.

Have you tried cleaning the carbs out, properly?

 

Here is a comprehensive guide to carb cleaning written by Rick from this site:

http://xjbikes.com/Forums/viewtopic/t=2908/

 

Don't be intimidated by the thought of having all the Carbs apart and mixing-up the Parts.

If this is your first shot at Cleaning Carbs, ...
Do (One) at a time.

Remove one Fuel Bowl and look things over.
Clean the Bowl.
Look for the litle hole in the bottom and squirt Carb Cleaner in there. (Watch your eyes)
Pull the Hinge Pin out of the Float ...
Look under the Float and watch the Float Pin come-out.

Practice putting the Float back together.
Dangle the Pin
Slide the Pin into the Float Valve
Hold the Float just right and replace the Hinge Pin ...
(That's the Hard Part and it's NOT that hard!)