no go after 5k rpm????

[65fury]

Okay so i removed and cleaned the carbs... put them back on.. sorta synced them... (they are close but not perfect) i need to find a good sync tool the one i borrowed was a bit goofy, so anyways bike runs fine up to 5k... then falls on its face and doesnt really recover... more of a stumble up to 8k. So what needs done? Im very new to tuning carbs on bikes...... im used to playing with big motors and diesels... bikes are new. Any ideas??

as far as mods... exhaust hacked up:confused2im a noob)
stock air filter and stock jetting as far as i know, i did try the washer behind the needle mod to get more mid range fueling.... but im not sure if it helped or hurt me:bang head:

Jason

 

[KJShover]

Assuming your putting all the arbox back together and on, before you test, It sounds just like you have an air leak somewhere.

 

[65fury]

yup the air box is altogether, minus the little "Y" piece on top.... could that be it? I forgot to choke it at WOT when it was falling on its face to see if it was running lean... ill try that tomorrow on my way to work... also where does one go for pilot jet and main jets? Ill need to do some rejetting when i get the kerker exhaust but i dont know where to buy any of the parts? thanks

Jason

 

[KJShover]

I'd spray some WD40 while the bike is running to check for some leaks. Some bikes run like ass without the "Y" mine included. Others run pretty well. Mine does well with a 1/8" shim for the "Y".

As for jetting with a Kerker without a DJ-7 or a Morley's, That depends on your elevation. I'm at 440 ft above SL. I'm a nut hair rich with 150's and could probably go down to 147.5's. I'd drop down to a 150 main to start, shim the needles, adjust the a/f screws and sync and you'll be golden.

I'm not running a jet kit but a Kerker and doing those little things helped alot. I have great mid and top end and a tire shredding low end and still get in the mid upper 30's mpg around town and 38-40's on the highway depending on how much my wrist twitches.

 

[naughtyG]

I'd say you just didn't put the airbox on tightly. The Max will not run properly without it.

 

[davidon]

What was the reason for taking the Y off? For stock set up leave it on.

 

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Check to make sure the carbs are seated in the boots the whole way, the airbox is seated on the carbs, the vent hoses are properly routed without being pinched, the filter is properly installed, and the lid is secured.

 

[Rollie]

Did you check / change the fuel filter when the carbs were removed ?

 

[65fury]

well the airbox is tight, no pinched lines or lose hoses either. I pulled the "Y" because i thought i was running to rich on the top end and needed more air... which i have found is not the case. Also tried the WD40 trick and couldnt find any leaks. I did shim the needles, but now that i think of it... it pulled hard on the top end before i shimmed them...... just the mid rpms were a bit sluggish. Oh and i disconnected the vboost so its always open.....mabe thats an issue?
Thanks

jason

 

[65fury]

Did you check / change the fuel filter when the carbs were removed ?

Yup, new fuel filter too!:biglaugh:

 

[KJShover]

I was thinking air leak, but considering how old your ride is. have you checked the rubbers on your slides? Might have a pin hole or two. if they do, your slides aint going to work right.

 

[65fury]

Well what do you know! after i put the "Y" back on and pulled the washers outa my needles my 6k and up seems fine... but my 4-6k is flat........ now what?

jason

 

[KJShover]

Well what do you know! after i put the "Y" back on and pulled the washers outa my needles my 6k and up seems fine... but my 4-6k is flat........ now what?

jason

Did ya do them both at the same time? if yes, then put the shims back in your needles.

umm, how thick are your shims? I've got 4 Yamaha shims in the wrappers. I'll send them to you to see if they help if you can deal with the flat spot for a bit.

 

[65fury]

Did ya do them both at the same time? if yes, then put the shims back in your needles.

umm, how thick are your shims? I've got 4 Yamaha shims in the wrappers. I'll send them to you to see if they help if you can deal with the flat spot for a bit.

Oh and i meant to write my 4-7k is flat... not 4-6k:bang head:


Actually no, i pulled the shims and ran it, it would pull to about 4.5k and flatten out, barely got it to 6k and it just didnt want to go anymore, so i pulled over put the "Y" back on and ran it, it pulled from idle to 4k good but kinda flattened out between 4k-7k then started pulling hard again(not as hard as it did when i bought the bike, but close) Also my vboost is always open... would that be an issue?

The washers i used were 1mm thick, not sure if thats too thick or not thick enough. How thick are your shims?

Thanks

jason

 

[KJShover]

The washers i used were 1mm thick, not sure if thats too thick or not thick enough. How thick are your shims?

.4mm Yamaha pt# 8AB-14227-00

 

[tvmax]

Stock exhaust? I'd check float level and put 150 mains in. Plug vboost back in. See how that pulls up top. Then shim from there for the midrange.

 

[65fury]

.4mm Yamaha pt# 8AB-14227-00

Hahahaha wow... i definantly had to big of washers:bang head::bang head:

 

[65fury]

Stock exhaust? I'd check float level and put 150 mains in. Plug vboost back in. See how that pulls up top. Then shim from there for the midrange.

thats kinda what i was thinking today, plug in vboost and see if that helps, what main jets come in here stock? 145s?

Jason

 

[KJShover]

what main jets come in here stock? 145s?

Jason

Mikuni 152.5

 

[65fury]

Mikuni 152.5

Okay so i should get smaller jets? im gunna hook the vboost up and ill test it and ride and ill report back in 20 min or so