Still cant tune my carbs

[65fury]

Okay well im finally back after my month long vacation........ and im ready to get this bike running right!!! So lets recap... my bike ran good from idle to 4k then sputtered and ran like crap till 6.5-7k so i added another spring to my slides to slow them down from opening to quick and i was able to get it running decent enough that way. Now im back and i pulled the extra slide spring and resync'd the carbs, went for a ride and it still runs like crap all the way to 7k from 4k. I pulled the plugs(which are brand new) and they are white as snow!. My mixture screws are 4 turns out, needles are stock and not shiummed, 155 mains and stock air filter and box. Full kerker 4-1..... i dont know what to do??? before i left for vacation the bike was running to rich... now to lean? i put almost 5k miles on the bike and ran sea foam thru it on the trip.

-Shim the needles??
-larger mains??(had 165s before i pulled it apart and it ran AWESOME!!!!)
-drill slides a lil larger???(they have a smaller hole than stock right now)

Jason

 

[KJShover]

white plugs = lean

How are your floats?

 

[65fury]

white plugs = lean

How are your floats?

Well when i left for my trip they were all at 16mm(wet level)
I wouldnt think they could change with just driving... but ill check them again tomarrow when i can. If they are still good, what else should i check?? thanks

jason

 

[KJShover]

... but ill check them again tomarrow when i can. If they are still good, what else should i check??

Jet up.

 

[RagingMain]

Jet up.

+1
Try spliting the difference between your rich 165 and your lean 155
Go for 160s

 

[65fury]

well before i jet up i just encountered another issue.... after church tonight i drove home and it ran like absolute GARBAGE!!! missing popping, dieing at idle. So i get home and pull the front two sparkplugs while the bike is running... and it doesnt change a thing!!! turned bike off and pulled all my plugs, all still white(lean) and checked to see if my plugs were getting spark so i held them up to the block while it was running. And they were sparking. But if i pull just one of the rear cylinder plugs it would die. So now i have a spark issue, which wasnt happening earlier today... but i dont understand why the plug is sparking when i hold it up to the block but if i pull that plug while its running it doesnt change how it runs.....:damn angry::damn angry:


Jason

 

[Damon]

Check your slow speed fuel circuits.

 

[SpecOps13]

Yes, slow circuit. I had the same front cylinder trouble with no change pulling the plug wire...

Good Luck

 

[65fury]

okay well i think yall are onto something, i can turn my mixture screws on both front carbs all the way in and idle doesnt change a bit, so whats that mean?? do the pea shooter or shotgun?? i dont know why both front carbs would just stop working like that:bang head:

Jason

 

[65fury]

Okay got the bike running on all 4 cylinders now, did the shotgun on all the carbs and also found that all my rubber o-rings in the mixture screws were all mutilated and in pieces!! cleaned them out and bam she runs again!! except for the lean issue i still have, so after the bike cools down im going to jet up from my 155s to some 160s....unless all i have are 165s, not sure what i have anymore.

When i went for a test ride after fixing the low speed cuircut, it still stumbled after 4k and didnt really clear up till around 7k..... but even then it didnt really pull hard at all...... im going to assume thats from it running to lean??

also since my slides have smaller holes in them than stock... should i drill them out to the correct size?? Thanks

jason

 

[65fury]

okay so i put my 165 mains back in and syncd the carbs, went for a run and i noticed it still stumbles in the 4k-6k range and then cleans up and starts pulling... altho it does pull harder than before, it still doesnt seem to pull like it did before i worked on the carbs. Im wondering if maybe i should start shimming the needles again.

Also with the vboost open it seems to almost get stuck in the 8k range(but only when in 5th gear WOT, if i let it pull from idle to redline in every gear it doeesnt seem to get stuck in the 8k range, but stumbles from 4k-6-7k.

Over all it feels like it runs better with the 165s compared to the 155s, but it still doesnt run right

Jason

 

[65fury]

anybody??? I know ive been picking everyones brain on this bike since day one and i just cant seem to get it right..... no matter what i change or do it never runs right, it seems like i fix one thing and another thing pops up....

Jason

 

[naughtyG]

If it stumbles from about 4k I would say your needles need shimming up a bit. At least that's easy to do, takes no time at all. Add one shim at a time and take it for a ride. You'll know when it's running good

Also, are all four of your slides diaphragms in shape? No tears, holes or anything like that?

 

[65fury]

If it stumbles from about 4k I would say your needles need shimming up a bit. At least that's easy to do, takes no time at all. Add one shim at a time and take it for a ride. You'll know when it's running good

Also, are all four of your slides diaphragms in shape? No tears, holes or anything like that?

Yeah thats tomarrows project, and yes on the slides , ive inspected them carefully and they are in good shape. I need to pull my plugs again too and see what color they are since the 165main swap.

Jason

 

[Rand-5107]

Hey, good to see we both survived our vacation rides. Will give you a call tomorrow. I still think a dyno with air fuel reading would be helpful. Rand

 

[65fury]

Hey, good to see we both survived our vacation rides. Will give you a call tomorrow. I still think a dyno with air fuel reading would be helpful. Rand

Hey man, yeah it was a good ride, all 4000+ miles of it!!! Just wanna get it tuned correctly now:bang head: id be all over the dyno idea if i wasnt pinching pennies right now.. sorta lost my job:damn angry:

Jason

 

[one2dmax]

You made a huge change and could have easily gone too far with it. But, the 4K stumble will be a needle issue anyway.

 

[65fury]

You made a huge change and could have easily gone too far with it. But, the 4K stumble will be a needle issue anyway.

Hey Sean, yeah big change on the mains.... but it doesnt seem to have an issue in teh top end, but even after shimming the needles it still doent have a smooth pull from 4k-6k, but pulls fine after 6k. I need to do some more runs and tests tomarrow, but my plugs are still looking a bit white so i might have a lean issue still:ummm:


Jason

 

[[email protected]]

Well, I'm not a carb guru but it sounds to me like you might be a bit off base with the changes you're making. It definitely not typical to have a kerker on the bike with the stock airbox setup and running 165 mains.

Based on what you said earlier about pulling the mixture screws and finding torn o-rings, and also needing to do the shotgun, I would think you may want to dig a lot deeper into the carbs to make sure everything is in good shape and CLEAN before you start tuning.

Take the carbs off. Fully disassemble. Clean everything. Make sure to remove jet block, all jets, clean them all out, replace any o-ring that looks bad, make sure jet block gaskets are good, make sure o-ring under slide cover is good, o-ring around emulsion tube, jet block rubber plugs, needle jets aren't worn, floats are right, etc. All the info you need on how to remove, clean, inspect, rebuild, and even replacement part #'s are sticky's in the carb forum.

Its time consuming but it doesn't cost a whole lot to do it yourself unless the slides or coasting enricheners are shot.

I would drill the hole in the slide to stock (at a minimum). Not sure how its smaller than stock? Did you epoxy it closed or something? Make sure you have the needle assembly installed correctly with the locating tab on the spacer locked into place. You say you have shorter springs than stock? Like stg 7 springs? Those would most likely be fine.

Once you're sure everything is in good order, and clean, I would go back to stock 152.5 mains, or even 150's, one shim on the needle (if stock needles) and about 3 turns out on the A/F screws and try it there. This is a generic tune that works well for most guys with the same setup you are running.

 

[65fury]

Well, I'm not a carb guru but it sounds to me like you might be a bit off base with the changes you're making. It definitely not typical to have a kerker on the bike with the stock airbox setup and running 165 mains.

Based on what you said earlier about pulling the mixture screws and finding torn o-rings, and also needing to do the shotgun, I would think you may want to dig a lot deeper into the carbs to make sure everything is in good shape and CLEAN before you start tuning.

Take the carbs off. Fully disassemble. Clean everything. Make sure to remove jet block, all jets, clean them all out, replace any o-ring that looks bad, make sure jet block gaskets are good, make sure o-ring under slide cover is good, o-ring around emulsion tube, jet block rubber plugs, needle jets aren't worn, floats are right, etc. All the info you need on how to remove, clean, inspect, rebuild, and even replacement part #'s are sticky's in the carb forum.

Its time consuming but it doesn't cost a whole lot to do it yourself unless the slides or coasting enricheners are shot.

I would drill the hole in the slide to stock (at a minimum). Not sure how its smaller than stock? Did you epoxy it closed or something? Make sure you have the needle assembly installed correctly with the locating tab on the spacer locked into place. You say you have shorter springs than stock? Like stg 7 springs? Those would most likely be fine.

Once you're sure everything is in good order, and clean, I would go back to stock 152.5 mains, or even 150's, one shim on the needle (if stock needles) and about 3 turns out on the A/F screws and try it there. This is a generic tune that works well for most guys with the same setup you are running.

All very good advice, but after cleaning the mixture screws ouut my "miss" went away, all the other tuning issues are issues ive had afor a while and ive tried allllll kinds of mains and needle shimming combos before, but after my trip from Texas to Colorado my tuning issues sorta changed, before my trip i was having what i thought to be a rich condition(my slides were drilled larger than stock so i redrilled to a smaller size, since i discovered my slides were opening to fast) My slide springs are actually stock.

Carbs have already been thoroughly cleaned and my only issue now is a stumble from 4k-6k, altho its not nearly as bad as it was a month ago. Shimming the needles seemed to help, but i also noticed a small stumble when im at 7k+ and then i go WOT it will studdar for a second then rip!! Im going to drill the slides to the correct size now since its running better.

I upped the mains from 155s-165s cause my plugs were all white( and brand new) and the bike was lurching and popping and backfireing, until i upped the mains and the plugs since then have gotten a tad more color. I might buy some 160s to try if i notice a rich condition, but so far the 165s have pulled the hardest on my top end over 150s and 155s, so until i get some 160s in there to test ill stick with the 165s.

Also all slides and coasting enricheners are in great shape, floats are all at 16mm wet level and when i swapped the mains i checked the bowls and they are all very clean still, no sediment or anything. I think from running sea foam thru a few tanks of gas has really helped clean out th ecarbs and motor cause it is running 80% better since i got back from my trip and i didnt change anything on my bike while i was gone.

Jason