help with vacuum leaks? high idle

hello all, i need some assistance again.

got the bike for free from my brother, his air box was toast so i went to pods, now im back to an airbox setup and k&n filter.

the air filter doesn't quite want to seat up ever, i think this is the main problem. no matter what i do with the airbox top, i cant get the filter to seat up properly. any tips?

i got a carb tune pro and the cylinders are pulling about the same, but i had to measure them while it was warming up, about 2k rpm

after the bike is fully warmed, it wont drop below 3k. after going to airbox, im up to about 40.5 miles per gallon. up from 36 with pods.

please help me! nothing i searched helped enough

 

You will have to get back to stock size jets, air getting in on the air box side of the carbs won't cause the high idle, are you sure the carbs are in sync, if they are you should be able to wind the butterflys back to closed & cut the idle right down.

 

Drill through the Locating Tap on the Filter into the Airbox.

Fasten the Filter in-place with a Small Sheet Metal Screw.

Alternatively:

Affix "Double-Sided" Trim Adhesive Tape to the Locating Tabs.

 

i know nothing about carbs, but if you're working on them at all i would definitely follow these instructions.
http://xjbikes.com/Forums/viewtopic/t=2 ... n+own.html
this is another excellent post
http://xjbikes.com/Forums/viewtopic/t=14692.html

 

thank you all, this was very helpful

the idle screw is all the way out btw. choke not engaged

i was trying to back out the fuel adjustment screws with the carb tune attached, but they all turn down except carb 3, correct? i ended up just getting them all as close as possible to one another. the bike runs great on the interstate but its embarrassing to hang out at red lights

 

Fabricate some device that will allow the Carbs to have Positive Main Air.

That will go a long way toward helping the situation.

 

My 2 cents:
Have you tried making the mix richer? This should automatically drop the high idle.

If this input makes any sense to you, check my one (1) post so far!

Regards

 

I did have a problem with mine and it turned out to be the fuel petcock. I rebuild it and the idle when down it was up to about 4000 drove 35 miles home through traffic that way.

 

A figment of the imagination.

 

I had the same problem with my '82 650 Seca. Turned out a few of the carb bodies were worn where the butterfly valve pivots. To verify this spray some carb cleaner on the carbs while running the bike and see if the RPM's increase. If they are pulling in air they're going to be junk. I went to a local salvage yard and picked up some carbs and used those.

 

it they are leaking around the throttle shafts it is most likely that it would need the seals replaced

 

#3 carb is the static carb on the 650/760 Maxim Secas. Fuel adjustment screws are located inside the top of the carbs. You most likely are referring to the the syncronizing screws (three screws, one between each set of carbs). You syncronize all other carbs to the readings you have on #3. Balance 3-4, then 1-2, and finally, you use the middle screw to balance the two banks (1&2, 3&4) together.
Good luck hunting!

 

omg, i cant believe i thought the synch screws were the fuel screws.

maybe i need to wait on another post, but where the hell is this fuel adjustment screw? the haynes manual points out a "special screw" in the (head) of the carb.

does this mean id have to remove my carbs from the bike, take off all the caps, turn each screw a 1/4 turn, replace carbs, start bike, swear, rinse and repeat???? uhhhg


ps: thank you all for the input, i appreciate the interest and free bumps

 

Depending on what you want to do, you don't have to pull out the entire carbs set.

The 4 fuel mixture screws are 4 small individual screws seated on top of each carburetor, just before the cylinders intakes (unscrewing these screws increases the fuel to air ratio). If your carburetors never have been adjusted before, the screws may still be covered by a manufacturers seal.

The 3 sync screws are seated in between your individual carbs.

You have 1 big main idle screw/knob/handle seated on the back of your carbs, pointing away from the engine. This screw is adjustable by hand. No tools required.

It has helped me to google and youtube words like; yamaha, carburetor, fuel mixture screws. You name it.
Not having a person in the know on hand makes understanding/learning an engine problematic. I know first hand! But it can be done.

Regards
DantheDane

 

If your only problem is high idle, then please check my post on the topic. It may just be a question of enrichening the mixture. I would appreciate your feedback, as I have had the same problem, and stumbled on the answer in my dreams, believe it or not!!

 

Wow, thank you globus and everyone else once again. I know why fitz hasn't replied yet now How many times have i already been told to check valve clearance and compression to determine the health of my engine.



I seek every one's help in a different matter!

I come to you all for help because i blew the head gasket in my 90 vw and this has been my only transportation to work and back every day 48 mile commute round trip and i still have no front brakes. Finally got the caliper rebuilt, D&D discount motorcycles, tempe. I love you guys,

new brakes, well, oh my god, what else could go wrong? The screws may as well be welded into the master cylinder reservoir. Got one out with a Grabit, reverse threaded bit but the second try yielded a broken bit.I dont have a heat gun but i could give my butane soldering iron a try. Reverse drill bit, not working through the grabit. Wish i had a normal threaded bit
http://i72.photobucket.com/albums/i181/ ... CF0693.jpg
http://i72.photobucket.com/albums/i181/ ... CF0692.jpg

I am a very careful rider but phoenix is not a place for a 30 year old motorcycle, to all i have flipped off and will continue to do so, please understand that your putting my life in the hands of one single copper wire or fuse. I would like to continue living. Thank you
I can control what happens in front of me, what i can not control is a sudden loss of power to my brake lights, to my engine, and a almost instant 30 mph drop in speed.

 

Snowy..... I don't think i'd be riding that bike..... id rather be late for work or have to find a new job then be dead. No front brake? Sudden power failure? Dude.... you're scaring the sh!t out of me!

 

Great pictures Snowy. Those are your fuel mix screws allright.

But I am going to have to agree with jmilliken. Your bike is in need of a serious overhaul. By your descriptions, I would get another bike in better general condition.

With the bike knowledge you have now, you should be able to find a decent xj somewhere?...

Don't risk your life.

Regards

 

in all seriousness, i was doing the math tonight..

50 mile commute, 22 days a month, since march 17th. give or take but still about 3200 miles, uhhg i need an oil change :wink:

My 80 gs1000 http://i72.photobucket.com/albums/i181/ ... CF0098.jpg was the most amazing bike ive ever owned(only other bike ive owned), swapped a new engine in it and it ran like new, these one and 2 owner bikes seem to be like this. But you get a bike thats been suxually abused so much like my own its hard to learn how these things are supposed to operate.


the gs would just die out on the interstate due to wiring to the kill switch. probably common in a bike that sits in the elements, however, i didn't know how to deal with this as well as other electrical charging issues that had recently arrived, as if my 8 month new stator had suddenly died. so i traded it for my vw.
http://i72.photobucket.com/albums/i181/ ... CF0630.jpg

Sorry, i love this picture of the bike junkyard.
http://i72.photobucket.com/albums/i181/ ... CF0523.jpg


Ill get this fixed in the mean time
http://i72.photobucket.com/albums/i181/ ... CF0514.jpg

been meaning to but i have to source everything. thanks xj4ever in your continued help in everything.i have a fuse pane. waiting for install.

its not as dangerous as i make it seem. i think i put a lot of doubt on a very reliable machine. after all, i still have yet to determine how an old prop plane worked. was it a single carb? someone tell me the carb setup on a p52 mustang!!! please!

meow
http://i72.photobucket.com/albums/i181/ ... CF0687.jpg


the bus, which is one single road, to the nearest location to my job. 2.15 hours. this is somehow not worth risking my life :wink: to add an additional 4.5 hours on my day rather than 1.

 

Umm... Yeah, it IS.

The bike you're describing has no front brakes. THAT ALONE is reason enough to not be riding it in traffic. Front brake is up to 90% of your stopping power.

Have you pulled the REAR brake apart, and physically visually inspected the shoes for delamination? Or are you trusting you entire ability to stop to a brake that is likely to suddenly and completely fail, with a good possibility of producing a rear wheel lockup?

HOW YOU GONNA STOP THE DAMN BIKE IF THE REAR WHEEL SUDDENLY LOCKS AND YOU GOT NO FRONT BRAKE???

And you wondered why I haven't responded yet. Because I have absolutely no interest in helping you get that deathtrap running so you can go out and get yourself killed, is why.

A 30-year old motorcycle IS NOT reliable daily transportation until you've been through it from front to back, and properly recommissioned it.

Until then, it's a disaster looking for a crash site, with you on it.

PARK IT until the brakes are 100% nothing less.