Ok so lets start with i bought it running for 400$ off my cousin. going for the street fighter look. theres no plastics whatsoever not even fenders. its a 92 f2 600 decent condition i guess. ive done some mods like removed all plastics, aftermarket headlight, intergrated turn signal tail light, dirt bike handlebars and rubber mounted risers drilled and bolted to the triple trees, removed stock head light and gauge cluster and put new speedo cable and 2.5 inch black 160 mph speedo on( no other gauges) and hacked down my dr. d slip on to make it a shorty.

now to begin with the tech stuff......

im a decent mechanic i guess, i built my 82 cb750 from the ground up and it runs like a champ but this rocket stuff has thrown me for a loop.

i know the basic principals of how to clean carbs so ive done that, before i ask these Q's i tried searching for the answers in the search function. i did a mild bench sync to the best of my abilities but the carbs still dont seem quite right. the pilot screws are two turns out, stupid me i forgot to right down jetting and clip position before i put it back together so ill get that tomorrow. i dont have a carb snyc tool so its kinda silly for me to ask this but i need help lol

it seems to idle fine theres a slight bog just off idle but once she catches up it hits rev limiter pretty quick, cruising down the road it runs a lil funky but i think that will go away hopefully with the bench sync i did cuz the butterflies were all outta wack ill know tomorrow when i ride it to work.

so lets sum up the questions here,

1/ what is the order of sync for the carbs? (on my 750 you sync #1 to #2, #4 to#3, then #3 to #2)

2/ its got a bit off a slow return to idle after revs but i think its becuz my airbox is a lil outta form so what is a good carb swap for these bikes? (i have a brand new set of keihin CR33 carbs sitting around but i believe the intake spigots are too large but i might be able to order some smaller ones, would those carbs be too much ?

3/ this is for all my streetfighter dudes, any references for longer cables for clutch, throttle, choke, speedo? all my cables are pretty tight due to the dirtbike bars being mounted ontop of the triple clamp.

thanks for any and all help i recieve!!!

 

welcome aboard! glad to have you.

the cb 750 and the f2 are both inline fours correct? if you can build that thing from ground up, you shouldnt have a problem with the f2. put eveything back to stock, buy a carb sync tool, i'd buy a set of used carbs off ebay.

there are some more people on here that have built f2's that can give more details about it than i can. thats just where i would start at.

 

Welcome to the forum, Greg!
I'm not sure why you're considering replacing the carbs, but that would most definitely be over-complicating things - the stock Keihin carbs are just fine, provided they are clean and setup correctly.

Let's talk about the issues with rough cruising and bogging off idle - this is governed by your pilot circuit, which is set by your pilot jet size, and the fuel screw settings.
When you cleaned the carbs, did you remove and soak all the jets: pilot, main, and needle jet holder? Before setting your fuel screws at 2 turns out, did you remove the screws and clean those passages as well?

I realize you might have already done this, but IF the pilot jet and fuel screws were not removed for cleaning, then I would start with this, to be certain those circuits are completely clean, and then I would move your fuel screws to at least 2 1/8 turns out, which is the baseline for all 49 state U.S. bikes. California bikes are 2 3/4 turns out, and Canadian bikes are 2 turns out. Bear in mind, these settings are for an OEM-type paper air filter, if you have a hi-flow filter, like a K&N, BMC, UNI, etc., you may have to adust them out a little further... if you have a 49-state bike with a hi-flow filter, I would probably just start at 2 1/4 to 2 1/2 turns out.

Like I mentioned above, the F2 carbs are most definitely adequate - unless there's physical damage to the carb bodies, or damage to several of the slide diaphragms, which are over $100 a pop, I would keep them. Did you by chance remove the diaphragm covers, and inspect the slide diaphragms for damage?

 

well replacing the carbs was just an idea for thought really. so the ride in to work proved to be better. theres a lot less stumble just off idle and the spudders while cruising 55mph is better so a lil more fine tuning and it should be good. i live in michigan so according to your specs i need atleast another 1/4 turn out on my pilot screws.

the carbs are fine theyre not out of alignment or damaged, just dirty. all parts that could be taken out were taken out and cleaned and air hosed off. I.E. floats, float needles, all jets, jet needles pilot adjusters, diaphragms, etc. there is an aftermarket airfilter in the airbox i do believe its a uni filter but it needs to be replaced becuz its warped and so is the airbox.

so i need to purchase....airfilter paper style or oem, better condition airbox, sparkplugs, tires and clutch plates. then ill get into replacing the elctricals like the regulator/rectifier, stator, igniters and coils, wires and such so everything like that is up to snuff.

thanks for the suggestions guys i really appreciate it

p.s. yes the 600 and 750 are both inline fours. the main difference? cb 750s are easy to work on! especially the carbs lol no disaasembling the bike to work on carbs lol

 

Sounds like you're on the right path - just go with an OEM-Type paper filter, and adjust your fuel screws another 1/8 turn out, and you'll probably be running well.

Good luck in your parts search!

 

im gettin there. another question, what is the stock jetting size? and also any ideas where to get longer cables? i could cut and make my own but i dont wanna go that route

 

Stock main jets are 135, and pilots are 38.

I couldn't help you there, as I've never run risers or dirt bars on an F2 - you should check customfighters.com, as I know there's several F2 streetfighter project threads there, and of course, search this forum for "fighter" or "streetfighter", and get in touch with guys here that might have knowledge on what cables are compatible.