Some issue - Surging, power loss

[mortation]

OK I am having a fit of new issues with the bike. It will idle down adn die when just sitting idling. When I was on the highway this morning you could feel the bike surging while I held the throttle still.just a little but I could feel it. And also the bike seems to hesitate/respond slowely to the throttle at take off or speed increase.

Argh. Any suggestions???

 

[the_journeyman]

Check the chain tension at several spots on the chain. My GS1150 does a fast surge at highway speeds. My chain is stretched & needs to be replaced and seems to be responsible since the surge disappears under hard acceleration.

On the dying thing, check your air filters. Mine wanted to do that, I cleaned the pods and they were very dirty. If your filter is really dirty, it might cause a rich idle mixture ~

JM

 

[mortation]

Check the chain tension at several spots on the chain. My GS1150 does a fast surge at highway speeds. My chain is stretched & needs to be replaced and seems to be responsible since the surge disappears under hard acceleration.

On the dying thing, check your air filters. Mine wanted to do that, I cleaned the pods and they were very dirty. If your filter is really dirty, it might cause a rich idle mixture ~

JM

Well I am 3 turns out on my mixture screw so I am making rich on my own As for the air filter it is a new OEM filter in the airbox. I will check it but dont think there is much wrong with it. And as far as the chain goes mines a shafty so no luck their. Thanks!

 

[Nessism]

You asked for suggestions so here is one: raise the needles. The needle has a broad effect on the mixture over various throttle positions - mostly parcial throttle. To richen the mixture you need to raise the needle. On my 550 there is a spring pushing up on the needle so in order to raise it I had to reduce the thickness of the shim ON TOP of the needle (under the plastic cap held on with a circlip). Chef says that Radio Shack sells a bag of washers that are the right size for experimenting. Take off the plastic washer currently on the needle and replace with a stack of metal washers. Remove washers to raise the needles (start with raising the needle about 1mm). Doing this helped clean up a lean hesitation on my 550. Easy and cheap experiment as long as you have the appropriate snap ring pliers necessary to get into the hole (I have some Motion Pro pliers that also reaches into the brake master bore).

Good luck and hope this helps.

 

[mortation]

You asked for suggestions so here is one: raise the needles. The needle has a broad effect on the mixture over various throttle positions - mostly parcial throttle. To richen the mixture you need to raise the needle. On my 550 there is a spring pushing up on the needle so in order to raise it I had to reduce the thickness of the shim ON TOP of the needle (under the plastic cap held on with a circlip). Chef says that Radio Shack sells a bag of washers that are the right size for experimenting. Take off the plastic washer currently on the needle and replace with a stack of metal washers. Remove washers to raise the needles (start with raising the needle about 1mm). Doing this helped clean up a lean hesitation on my 550. Easy and cheap experiment as long as you have the appropriate snap ring pliers necessary to get into the hole (I have some Motion Pro pliers that also reaches into the brake master bore).

Good luck and hope this helps.

Hmm I have the snap ring pliers from when I rebuilt the carbs and I am sure I can get some washers. I guess I got no choices but to give it a shot Thanks!

 

[mortation]

I think I may have a spare set of those plastic washers from some other slides. Can I use those or are they going to be to thick? What length should the needle be?

 

[trippivot]

bad idle and surging

bad idle and surging

this is a common problem when two or more tunning details are out of adjustment.

I suggest getting it to idle first then move on to running condition because there are only 3 things needed to have your bike running excellent
1 equal compression = tight leaky valves give problems
2 timed ignition good blue spark at the correct time
3 proper fuel and air mixture

start with:

good and clean spark plugs. solid plug wire connection and resistor caps with equal resistance.... then

check that all 4 exaust pipes are near to the same temperature-- a cooler pipe will be the problem cylinder/cylinders ie: #1=275 deg F #2=290 deg F #3= 160 deg F #4=300 deg F #3 being the problem -approximate temps- but close enough to get the message across. I check with a laser temp gague but a water spray bottle is good indicator too( steam or no steam)

3 turns on the idle mix screws is a little excessive,if it gets that far I suggest the next size up on the pilot jets. I suspect that there is a partial blockage in a pilot jet or bypass passage in the carb body/bodies and there might be more than 1 carb giving you trouble.

the list can get long but equal float heights are important
ignition timing is a factor a properly adjusted cam chain

I hope to get you on the right track

more info is needed for me to go on with pointers of what to check

 

[t3rmin]

I'd bump up the pilot jet. See this page:
CV Carb Tuning Procedures