bike not running right

Hi everybody! I hope someone will be able to help me with problem. My bike will not idle properly. It sputter when rolling on the throttle until rpms get up to between 2500 to 3000. Idle goes up and down on its own. Plugs were covered in dry black soot, cleaned plugs and reset idle mixture screws to 2.5 turns from bottom, as screws were out about 6 turns. Then could not get to idle. I cleaned carbs before as bike had sat for five years. I did not have chance to check plugs after carb adjustment because of lack of idle.

 

How did your pilot jets look when you cleaned your carbs?

 

when you cleaned the carbs, did polish the slide bores and give them a clunk test? this will cause a stumble off-idle to about 2k or so.
if you search on it, you will find some write-ups on it by RickCoMatic. He is our resident mechanical genius. Our Miyaga to Daniel.
Second, check the floats for height. There is a good article on this as well. just search for float adjustments
is the bike stock overall? stock jets, stock airbox, etc?
you are overloading on fuel which could indicate a stuck needle also.

when you cleaned the carbs, did you happen to clean the emulsion tubes and pilot circuits? lack of idle indicates plugged pilot (idle) circuits. the emulsion tubes are where the needle drops down and helps control fuel flow from the main jets.
if you look up Rick's posts, his signature has links to cleaning carbs. it is very very thorough. once done right, your bike could run quite well.

oh- if your idle is surging up and down, could be an air leak. grab some carb cleaner or a propane torch. spray around the throttle shafts and intake boots and see if that changes anything. it could be air leaks are causing you fits.
good luck! you will find a lot of people on here are very very helpful when it comes to these things.
If all else fails, you could beg for help and someone close to you may help out.

 

I cleaned pilot jets by soaking in carb cleaner and used piece of wire brush to make sure hole was not blocked. No did not clean emulsion tubes. Yes bike is stock overall, stock jets, and stock air box. I did`t check float height, but did remove and clean float needle and seat. I didn`t polish slide bores but after cleaning slide they were dropping ok. I was reluctant to disasemble carbs to much as was first time I had ever work on carbs on motorcycle. I am mechnically inclined and as have brother in law who has been working on bikes for many years. I think I was in too big of a hurry to start riding bike and there for was probably a little sloppy. Unfortunenately only have access to bike on weekends as it is stored at brother in law shop.

I will look at Ricks posts through the week and do better job of cleaning carbs.

When I was first working on bike did not have manual for bike but have one now.

 

all of us get in a hurry when we first get a bike. I was the same way...
bald tires, idle stuck at 4k and no tag
but I was cruising the neighborhood!
:lol:

 

The carbs the carbs the carbs, unless theyve already been cleaned new sealed, everything right and in its place and synched it wont run right (apart from electricals) which is what it seems you need to do. Mine sat for years and when I got the urge to git it goin again it ran,but bad, did the full carbs procedure and now it runs smooth at any revs. Search the forums, help is there........On the topic of gettin ya first bike and rushing into it... had my first about a week and HAD TO go for a ride one very wet and cold evening. Coming to a bend I thought I wouldnt make it through, I slowed right down and stopped on the edge of the road, put my feet down,but was so close to the edge there was nothing under my left foot, bike `n me fell down about 10 feet into a blackberry patch. We were OK but had to get a mate to tow the bike out.....very embarrassing. So if there`s a moral there,take it one step at a time.....And hope that little story raised a smile here `n there.

 

Bushy, your fall off the side of the road would NEVER happen over here! We fall off the road when our RIGHT foot reaches down for road and meets air.

I was trying to visualize in my mind what happened to you and it wasn't adding up until you wrote ".... had to get a mate to help ......". It instantly became obvious! One of my bikes would likely be totaled by the insurance company if it fell 10 feet as it would break so much plastic fairing pieces that the repair could quickly exceed the value of the bike. Gotta love our XJ's! Drag 'em out of the bushes, (right or left side of the road) , dust em off, and ride off into the sunset!


Nice!

 

I was reading post on clunk test and was wondering if I could use lapping compound to clean piston bores or would this be too abrasive for cleaning purposes.

I was also wondering if there is a way to print out post on carb cleaning procedure.

Thanks for all the help

 

valve lapping compound is too coarse for this. if you get 600, 800 and 1000 grit wet/dry sandpaper and evenly go up and down, you will get it pretty nice inside. use wd-40 or equivalent as the lube for the sandpaper. you can probably finish it with jewelers polish or even auto polishing compound. if you have a terry cloth attachment for a drill, you can probably use that too. get them shiny! dont orry too much about the pistons though. they tend to repel the nasties.
be careful of getting the compound down in the emulsion tubes though. heck, pop them out and clean them really good while you are in it.
you can print posts from the site, but its kinda ugly, but will suffice i am sure.

 

Ok thanks for info

Yes I will be disassembling carbs completely to do proper cleaning this time as cleaning was rushed last time.

 

I spent all day yesterday cleaning carbs. Today was the fun part of reinstalling carbs. Oh those darn rubber boots in air box.

I bit of a had time getting bike to start but after about five minutes of trying it finally fired up and ran great.

Now I am have issue with it be slow to return to idle. When cleaning carbs did clunk test to make sure all slide dropped freely. I lubricate throttle cable and remove grip and cleaned and lubed where grip sits in housing. Carbs were bench synced as per Rick`s post.
I used set of vernier calipers to verify all throttle plates were equal distance from face of throttle body. I will be doing air leak test tomorrow to rule out this as cause of problem.

I would appreciate any suggestions as to what maybe cause this problem.

 

run the air leak test. if you did everything right, one of the last items it could be is an air leak.
if there isnt a leak, you will need to probably sync them with a gauge and a YICS block-off tool.
what are the condition of the intake boots? any visible cracks?

also, you might consider a plug chop once it gets fully warmed up. take it out for about 15 minutes or so and then on the way home just before your driveway, have it at 4k and pull the clutch and kill at the same time. coast in and check the plugs. if one is lean, it could be a leak on that cylinder.
also, after a long ride like this, see what the idle is like. high? normal? low?
if it is a bit high, adjust it down a bit and then take it back out. see if it returns to normal then.

 

Intake boots look good. No visible cracks. Bike has not be driven on road as I am still learning to ride. I was think maybe it may just need good ride.

I should also have mentioned that idle mixture screws are set to 2.5 turns.

I rode bike in front of brother in laws shop for five minutes and checked number 1 spark plug was clean. I will check other plugs tomorrow to see what they look like.
I don`t think this was long enough but before carb rebuild plugs would foul with dry black soot fairly quickly.

 

definitely sounds like an air leak, i am pretty sure i got the same thing goin on but ive been to cheap and lazy to pick up a propane torch to do it with

 

I did air leak test to today. Happy to report no air leaks were found. When first starting bike today fired up on first push of starter button. Once bike was warmed up revved it up to 4k let go of throttle it dropped down to idle right a way, needle on tach was slow to come down. I think maybe lubing of throttle cable and grip might have helped with slow to idle problem.

I would like to say thank you for everyone helps.

 

you might consider unhooking the throttle cable and using a screwdriver to pull the throttle up and dropping it. see if it returns to idle quickly that way. rule out the cable as the cause.

 

When letting go off throttle the idle returns quickly but tach needle returns slow. When throttle cable is unhook throttle on carb slams shut. I have not tried this with bike running.

 

is your tach mechanical or electronic?
I dont know about the 84 model. if the idle drops to normal and the tach is still coming down, sounds like you are in the market for some graphite in the cable.

 

Tach working properly now. Had first real ride last weekend and bike ran great. I checked plugs after ride, one clean and three black. Adjusted mixture screws but did not ride bike after adjustment.

I will not ride bike until next weekend due to injury while out on first ride. I am ok except for sore knee. The injury will not deter me from riding again just need time to heal.

I should also mention that bike only received minor damage, a few scrapes and bent handlebar brake lever. I am wondering if it is possible to straighten or not.

 

well... don't worry about a little pain here and there..

but please consider investing in some crash gear.
chap can be gotten for cheap off ebay and any leather jacket will help.
helmet will save you from facial reconstructive surgury.

all of this i KNOW.. i learned how to ride on my own.

also.. if practice is needed, see if you can find a big lawn or field to train in
i learned on a back lawn and dirt field roads, and i bacame a much better rider because of it.

"dirt tracking" allows you to learn how to control a slide, this being a good thing to learn on a bike.

I'm sorry, i don't mean to preach.. Good luck!!

and we are all root'in for ya!!!

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