Hayabusa working on 2 cylinders!

Mr Bogus said:
oh yea.. :welcome::welcome:

takes spark, fuel and compression to make a motor run.. should always start with basics first.. tearing stuff apart and fixing it without can cause more trouble..

You can go from 1 issue to 2 without even realizing it..

I generally spin a motor over and listen to it.. Many can hear a low cylinder (or multiple) instantly.. from there I usually shoot a bit of carb clean down the intake and see if it tickles the motor.. (In your case you would give a shot down each velocity stack and see if it picks up the cylinder momentarily..)

if the motor "sounds" physically ok and the carb clean does not do anything, it would be time to check spark.. if that appears ok? time to get bit more physical and do a compression check..

when it is two adjoining cylinders? I would be a bit more worried..
Click to expand...
don't use carb cleaner. it will melt the seal around your throttle body bore, and cause a high uneven idle. something else flammable will do, just not carb cleaner. there's a story that goes with this advice, lol, be happy to post it.
 
well thanks for all your suggestions ...but i ve already checked all this stuffs ....i ve pulled each plug n checked which cylinders are not working and on pulling plug of left side two cylinders ....there appears no change in engine idling and reving...and on pulling any of other two plugs ..bike just get off...so it means that this cylinders are working fine ...also i ve checked all fuel lines ....all injectors are spraying at a time ...spark on all cylinders is gud ...there are no defects in wiring side ....i ve started bike after 4 months ...n since then bike is havin this problem!..my mechanic says that it may be a leaking head gasket that causes compression leak between those two cylinders or valve band or valve sheat leakage ...please suggest what should i do nxt !..thanks..!
 
ogre said:
don't use carb cleaner. it will melt the seal around your throttle body bore, and cause a high uneven idle. something else flammable will do, just not carb cleaner. there's a story that goes with this advice, lol, be happy to post it.
Click to expand...
I can assure you that a burst of carb clean is not going to affect the seals... Not sure what products you use but a hydrocarbon based cleaner is not going to affect the rubber boots when used in this manner.. Any cleaning product can cause damage to coating materials (often on the actual butterflies) but this is NOT going to cause a problem.. this is not a soaking we are doing...

viwo_54 said:
well thanks for all your suggestions ...but i ve already checked all this stuffs ....i ve pulled each plug n checked which cylinders are not working and on pulling plug of left side two cylinders ....there appears no change in engine idling and reving...and on pulling any of other two plugs ..bike just get off...so it means that this cylinders are working fine ...also i ve checked all fuel lines ....all injectors are spraying at a time ...spark on all cylinders is gud ...there are no defects in wiring side ....i ve started bike after 4 months ...n since then bike is havin this problem!..my mechanic says that it may be a leaking head gasket that causes compression leak between those two cylinders or valve band or valve sheat leakage ...please suggest what should i do nxt !..thanks..!
Click to expand...
Without hearing the motor crank over? I would suggest a compression test.. (as I posted earlier, 2 adjoining cylinders not working is usually not good)

It "could" just be some gummed up valve guides if the thing has been sitting a long time..
Blown head gasket is also a good possible but it did not "just happen" sitting there.. usually some other circumstance involved..

Vehicles left to long term storage tend to "break" in pretty standard ways.. The gummed up valve train is one of the most common..

I have had "some" luck fixing them without tear down but I consider this a bad idea.. If this is a "stuck" valve guide issue, it really needs to be takend apart and fixed before it hangs a valve at "RPM" and kills something..

no matter what you do, DO NOT sit there and try to fix it by "winging" the motor at high RPM and dumping crap down the intake (this used to work 20 years ago, today? clearances are too tight)..

Get the compression check (with ALL plugs out of motor.. pulling 1 at a time could cause a false reading, will still be low but false)

let the cylinder hit maybe 4 times and take the reading...

if the valves are hanging up , it is possible to get full compression if you zing it long enough.. we just want to see it hit solid in the first few rev's

post back after you get done..
 
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well thank you ...but finally after checking all the stuffs my mechanic has disassemble the head and found that t exhault valves of both that cyliinders are havin lots of carbon and also there is a leakage in valve seat which is causing this problem...head gasket is gud .,there is no problem with it.exhault valves of working cylinders are n very gud condition and they are pretty dry too in comparison to the valve of non-working cylinders...nw ll see what happens ..!
 
kwell guys ....my mechanic has overhaulled head assembly...n he found that there was leakage in exhault valves of that two cylinders....but then he has done all valves grinding n cleaned all stuffs ...head gasket was gud so he fitted old one only ....but after doing all this stuffs ...the problem is still appearing ...the headers of the two cylinders (CKP sensor side) still remains cooler than the other two ones ..n sometimes it also does backfiring....!pls suggest some more things which can solve this problem...thnkz..!
 
probably not..

leaky guides, poor oil quality, lots of short trips, lousy oil change schedule to go with short trips, really poor quality fuel, engine running "too cool"

So there are a number of reasons that can cause the carbon fouling..

I would put my best guess on lots of short trips and low operating temps.. I have 31K on mine and it was spotless..
 
If there was a lot of carbon in the exhaust it would be running too rich. Sounds more like it has an injector problem if the spark is good. I would clean the injectors to make sure they are opening and closing properly. If it can't close all the way it will foul the plug.
 
The first thing you should do is a compression test. You will need to remove all the spark plugs. We performing the compression test make sure you hold the throttle wide open to get the correct reading, witch is 171-228psi. If, you get a reading lower than 128psi you make have a real problem. If there is no problem with compression I would check check the timing to assure your timing chain has not jump time.
:thumbsup:
 
kwell i ve also done compression check and its all right...n all fuel lines and spark lines are also ok...so i think there may be some problem in some sensors ..can you guys tell me which faulty sensors can cause this problem?
 
viwo_54 said:
kwell i ve also done compression check and its all right...n all fuel lines and spark lines are also ok...so i think there may be some problem in some sensors ..can you guys tell me which faulty sensors can cause this problem?
Click to expand...
so your guy re-vamped the head and the thing is still broken?

back to basics...
Compression (should be a given at this point but hey, you just spent how much and it is still broken?)

Fuel: IF there is no fuel going down the port, it cant run.. (this could also be why a spark plug would appear oily FWIW) again a quick blast of carb clean down a port should pick the cylinder up if it is fuel starved..

Spark: pull the plug wire off, put a screw driver down the thing and hold it about 1/2" away from the frame.. make sure the spark is strong and blue, orange/red is bad..

You gotta know which of the above is wrong before you can do much of anything..

What strikes me as odd is that you have a guy that can overhaul a head but can not diagnose a basic "no start" condition... I would be afraid....
 
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kwell that guy had already checked all basic things and thenonly decided to re vamped head as he guessed the problem may be leakage of head gasket....but well after opening head the packing was all right but exhaults valves were full of carbon so he just grinded valves and refitted head assembly without changing head packing ..but still problem is not solved.In fact now sometimes coolant is overflowing from radiator !bike is still just 11000kms done..!
 
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kwell that guy had already checked all basic things and after that he decided to re vamp head as he guessed the problem may be leakage of head gasket....but well after opening head the packing was all right but exhaults valves were full of carbon so he just cleaned grinded valves adjusted tapets and refitted head assembly without changing head packing as he did nt findanyproble in it..but still problem is not solved.In fact now sometimes coolant is overflowing from radiator !bike is still just 11000kms done..!
 
So after the head work you have a overheating issue? What does the guy that just worked on your bike have to say? I am assuming he said the work he was going to do was gonna fix your problem.
 
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