bloody bike!!

Hi

ive got a xj650 maxim and it was running rich ive used colortune to get it burning correctly.. all cylinders burning a lovely blue colour now..

The only problem now is that its popping at low revs??

i'm wondering could this be the carbon build up coz of it been running rich..

or could it be a valve?

any ideas ...

lets start easy then move harder ...lol

cheers

 

Ahhh, I think you did the same thing I did to mine when I first colortuned it.

Mine will show that pretty color blue for dang near a full turn before changing, so I was like "what gives? Whats the sweet spot?"

Well...

I finally found a very informative post on how to properly colortune.

So basically, get a yellow/orange glow then in very small increments dial it so that it just turns blue.

Until I found this information mine was doing a bit of popping here and there, especially when shifting. Now she starts better, idles better and seems to drink less

 

thats what i did yellow/orange colour then turned it till it just turned blue. it idles ok just now and again it pops. it revs perfectly. so wonder if its just carbon build up??

 

One other thing to take into account is the dreaded "Previous Owner Syndrome". So, unless you have owned the bike since new, you never know what the P.O. did to the bike. He could have had an after market exhaust on and made jetting changes and then when he sold it to you he may have put a stock exhaust on and left the jetting the same. That may explain your issues with it running rich since you've had it.
Then again, it could just need a good cleaning to make sure everything is doing what it's supposed to do.
Do you have the P.O.'s contact info still? Call him and see if he has any history on the bike.
My 2 cents.
Good luck and keep us informed how it turns out.


Cheers, Graham

 

Veldalkin, I'm curious about something and want to see if you had the same thing as me (although now that I think about it I was doing it at 1100 RPM's). I would have both blue and yellow for about a half a turn. so i'd have to keep turning until it was Only blue. Did yours )or anyone elses) do the same thing?

 

my very first bike was an 82 maxim 650. i used regular leaded gasoline. after awhile it got carbon buildup and ran like crap. 30k miles at that time. i took into dealer for it's first valve and carb adjustment. hoping that would fix the problem. instead, the dealer told me to use unleaded gasoline. after about 2000 miles of unleaded gasoline. the bike ran like a champ again.

leaded gasoline hasn't been used for about 15 years now. i think carbon build up is a thing of the past.

 

ColorTune find you where the Pilot Mixture Screws needs to be for the Bike to have a PERFECT IDLE Mixture.

The Bike will IDLE like a Sewing Machine until it runs out of gas.

Getting the Bike to RUN Right is another thing.

Use the ColorTune Plug to get the Bike to IDLE with the Throttles Closed.
Thus BEGINS Fine Tuning.
When the Colortune Plug shows you a nice Bunsen Burner Blue; you have arrived at the spot from which Fine Tuning commences.

You still need to let the Engine have Pilot Mixture in excess of Blue to supply enough Fuel to adequately enrich the Air that sneaks-in when the Throttles are cracked-open and a breath of fresh air is let into the Cylinder without carrying any Main Jet Fuel.

You already did the hard part; thanks to Colortune.
Now, you need to adjust the Mixture to Fuel the very briefest of moments where the Engine needs some gas sustain combustions.

You aren't far off if you Colortuned it.
This is where you put the FINE in Fine Tuning.
If we called ONE Complete Turn of the Pilot Screw "1-Minute"
Adding what additional enrichment is needed might be as little as: 6 -to- 8 Seconds.

Removing "Pop-pop-poppidy's"
2 or 3 minutes ... just a nudge.

Depending on how well you Colortuned.
Going from:
Being a bit too Lean ...
-to-
Being a bit too Rich ...
Might happen in an adjustment that moves the Pilot Screw as little as 6 -or- 8 Minutes.

 

Just a wild guess, was it #3 or #4 carb you had trouble with? Until I used a YICS tool when colortuning, I had trouble dialing in the "blue" on 3&4(mostly 4). So I just went with the pulse. I found myself staring at the firing pattern and noticing that at some spots it fluttered with perfect consistency, and then intermittent above and below that spot. I went really rich then backed up until I got a little blue mixed with the yellow. Then dialed it a tad more till I saw it pulsing perfectly. With the YICS tool, it was much easier.

 

i will re tune when i get a yics tool..and i will try fine tunning as i only got yellow/orange then turned it till it went a blue colour .. i will give it a small tune a little more with the mixture screw adn see what happends ive got nothing to lose..

if all else fails might then see about the valves...dont fancy doing the valves at mo..can it been done with the engine in place..

 

just to add if the carbs are out of sync will this cause it to pop aswell???

 

janevinnie, yes if they are out of sync. did you only bench sync?

also, remember, the rich end of the blue, cause I see blue for multiple turns, but again, I was only at 1100 RPMs...

 

Don't forget that "Dialing-In" the Mixture is going to vary from Bike to Bike, ... depending upon the condition of the Engine.

Bikes with Cylinders that are boarder-line for Compression will likely have trouble being Colortuned and may deliver erratic performance while BEING Tuned and remain troublesome AFTER getting Tuned.

The Colortune Plug might not work in a Cylinder with low Compression.
But, the Cylinder can be made to Fire by employing a Hotter Plug.

 

cheers all no ive not sync'd the carbs at all so will have to do that too now ..lol need some carb balancers now... money money money ..

 

I made my own out of some clear tubing, vacuum line, tee fittings and auto trans fluid. A lot cheaper and works fine if you don't want to spend the money. I'll be digging it out this weekend probably if you want me to upload a pic.

 

yes please that would be helpful

cheers

 

If I remember and it's easily accessible I will grab one for you tonight.

 

ok here's a pic of my set-up there is about an extra 6 feet of tubing past the end of the board. I'd say the board it's zip tied to is about 4 feet long or so. I don't have any vacuum line in the ends right now but I would suggest using that, when I first did it I just had the clear tubing. #1 it wasn't a small enough diameter and #2 it doesn't like heat. I would suggest at least a foot of the vacuum line to get the clear away from the heat of the engine.

 

cool thanks..