Still have problems after carb removal/rebuild

[ejoy1220]

Originally posted by oldyam80sg
Just curious how old is the battery? My SG sat in a storage unit for a while until i was able to get the bike to run well enough to bring it down to work on it at my Moms house.Even then i must have started it at least 30 times and it still had enough juice in it to start when i finally went back after 2 months.If i start my bike in May and don't run it until September it will still start with a good battery.

Maybe 6 months old? Acid/water is up to level too.

[ejoy1220]

OK got a rough carb tune in and took it for a ride.

Bike idles and revs in neutral perfectly fine, it flat out roars. Under load when being driven, you hit 4-5000rpms and it breaks up badly, hitting a wall and sounding like a machine gun.

Also, the nipples on carb boot #3 keep blowing the cap completely off. It will backfire, and when I get it back to the garage it's gone. Happened three times out of three, I'm starting to run out of caps!

Any ideas?? I'm starting to get sick of trying to get this thing running, I just want to ride it

[ejoy1220]

Anybody? Bueller? Bueller??

[oldyam80sg]

Mine backfired after using the bread tie sync.I backed off the mixture screws maybe 1/4 turn.That stopped the backfiring for mine.Are all the cylinders hot?Spritz some water and see which pipes steam.Mine would run fine and idled fine then 5 minutes into a run around the block it would run like crap.It turns out i was not getting fuel to the carb.

[AlanB]

Hi ejoy,

4-5k rpm is right in the middle of the part of the range covered by the needle. it is not easy to see why it would blow a cap off there, unless a "dead" cylinder was coming to life there.

Are you sure that all four are hot at idle?

Are you SURE you have got rid of the flooding when the bike sits?

Keep at it; doesn't sound too bad!

AlanB

[ejoy1220]

OK, worked on the bike some more this weekend. We tested all of the ignition components, new coils, new wires, regapped the new NGK plugs, everything is connected, etc etc....and we're still having this problem. Like clockwork it happens at 4500rpms, and almost sounds like a rev limiter (which the bike does not have). We recorded it on my dad's camera and put it on YouTube for all to see

http://www.youtube.com/watch?v=XTt7v-DoM_Y

Those with speakers turn them up, the noise occurs at the 3-5 second mark in the video.

Next step is to pull the carbs again and put the stock jets back in like petejw suggester earlier, as we have absolutely no idea why the bike is doing this. Under no load it revs freely and screams, but under load it falls apart.

Originally posted by petejw
just out of curiosity,
did u ride the bike after u put
on the exhaust/ pod filters.
or did u just rejet and hope 4 the best.
there are times when u dont need to rejet,
mayb ur original jets may surfice..

[xs11jack]

Tach?

It does sound like a charging problem, does your tach work? It runs off the alt. Also, don't throw a large quanity of amps at the battery. They tend to over heat and warp the plates inside. I don't use any charger that puts out more than one amp. If you are like me and don't throw the old chargers for electonic stuff, you can find a 1 amp, 12 volt dc. charger that will do nicely.

[ejoy1220]

Re: Tach?

Originally posted by xs11jack
It does sound like a charging problem, does your tach work? It runs off the alt. Also, don't throw a large quanity of amps at the battery. They tend to over heat and warp the plates inside. I don't use any charger that puts out more than one amp. If you are like me and don't throw the old chargers for electonic stuff, you can find a 1 amp, 12 volt dc. charger that will do nicely.

Tach works perfectly. We've tried two different batteries in this bike with the same results, as we thoguht at the beginning it was due to a weak battery. The trickle charger I have now is .5-1 amps.

[wingnut]

Check The pick up coil wires for breakage inside the insulation. There are a bunch of threads on here as to how to do it. Keep at it. You will be glad you did

[ejoy1220]

Originally posted by wingnut
Check The pick up coil wires for breakage inside the insulation. There are a bunch of threads on here as to how to do it. Keep at it. You will be glad you did

Did that yesterday, wires had no breakage inside the insulation and good continuity, and riding it with the cover off you could see the timing advancing, so that's working.

[petejw]

hey ejoy,
still sounds like the carbs
wat throttle position is it occuring at?
sounds like it could still b an off idle stumble, tho its still occuring under load.
wats it like in a higher gear at speed, thru the throttle range?

[mro]

When you cleaned the carbs,
Did you remove the diaphragm ass'y and check the rubbers integrity (no holes etc.) Would check needles are not bent or worn.

Might also check main nozzel was not replaced by a PO with the wrong type.


mro

[ejoy1220]

I'm going to replace the pickup coil wires tomorrow. Just thought of something else too.

The coils I used to replace the stock OEM coils were the ones from Mike's XS :

http://www.xs11.com/forum/showthread...threadid=12452

Now, this thread says that in order for the coil to get the full 12v, the ballast resistors on the older bikes need to be bypassed. This has not been done on this bike. Would this be causing problems with the bike running, and should I bypass them??

[3Phase]

Yes, that would do it; like throwing a switch.


Regards,

Scott

[petejw]

hi ejoy,
mikesxs sells 2 different coil types
one with 1.5ohms the other 3ohms
the earlier bikes take the 1.5ohms
or u can put the 3ohms on if u bypass the resistor.
do u know which coils r fitted?