Author Topic: just a note (Read 4738 times)

cd811 · « **on:** January 30, 2006, 07:00:14 PM »

when I first built my bike ,everyone told me I needed set my carbs like so(lower needle clip from middle to second from bottem, and rejet(start at 40/ 120))...(running open pipes and pods)...
anyway...it started right up and ran good accept for at cruise(or steady throtle)...so I played and played with jets(up to 145 main) and airfilters until...I pulled carbs back off and put clip in the middle and went to 40/120 jet and...perfect...

...sometimes more ain't better

Lumbee · « **Reply #1 on:** January 30, 2006, 08:11:00 PM »

...glad u got that figured out Carl...mines sitll cut'n out at highway speeds. I've got the 77/78 and my needles don't have clips

Though I can adjust the needle from the caps on top of the carbs. Anybody know if that does the same thing that moving a needle clip will do?

mrbreeze · « **Reply #2 on:** January 30, 2006, 08:41:55 PM »

Hey cd811...what altitude are you at? I'm at sea level and runnin 138.5 mains on the 2nd notch from top. Thats where mine goes good all through the throttle openings.

eldar · « **Reply #3 on:** January 30, 2006, 08:52:57 PM »

Lumbee, the screw/nut combo is used to adjust sync. We really cant raise and lower the needle like that so to speak. However, we still have the full range of jets sizes available to us. When you turn that screw, it actually moves the whole slide not just the needle.

mrbreeze · « **Reply #4 on:** January 30, 2006, 08:59:01 PM »

Thats why the "NEWER" SOHC's are so doggy!!!!

seaweb11 · « **Reply #5 on:** January 30, 2006, 10:22:01 PM »

78K Running pods, Mac 4-2 140 mains at sea level Runs STRONG in all throttle modes

bogged down a bit in the mountains in Northern CA and at "Crater Lake" last summer, but that's up there! 4000+

mrbreeze · « **Reply #6 on:** January 30, 2006, 11:47:16 PM »

Just ribbin ya Seaweb! (Man,these 78' guys are touchy!!!)

eldar · « **Reply #7 on:** January 31, 2006, 07:52:22 AM »

Thats because we get all this crap from you oldsters! At least we Got the nicer single brace front fenders!

Lumbee · « **Reply #8 on:** January 31, 2006, 08:06:53 AM »

...single brace? I don't know eleder...my 78F has two braces

..on the carbs..yea, that makes sense about those bolts moving the whole slide up. I put in 140's this past weekend and out on the interstate it still felt like it was cutting out. I'm experimenting with coving the pods with duct tape to restrict the air flow some. I also took some 110 jets and drilled them out with a 1/16 drill bit. I think that would be equivalent to around 1.5mm (150's

)

ohiocaferacer · « **Reply #9 on:** January 31, 2006, 08:30:31 AM »

Quote from: cd811 on January 30, 2006, 07:00:14 PM

when I first built my bike ,everyone told me I needed set my carbs like so(lower needle clip from middle to second from bottem, and rejet(start at 40/ 120))...(running open pipes and pods)...
anyway...it started right up and ran good accept for at cruise(or steady throtle)...so I played and played with jets(up to 145 main) and airfilters until...I pulled carbs back off and put clip in the middle and went to 40/120 jet and...perfect... ...sometimes more ain't better

I've been telling people to leave the stock jet and carb setting forever. These older CB's arent like the new bikes that are leaned all to hell and back to meet the post 1980s emmissions regs. These bikes can run open carbs and exhausts all day long on the stock carb settings.

Also......if a bike is cutting out at 3/4 to full throttle......check the float heights first, before screwing with jets. I have seen tons of bikes with improper float heights.....and this give the same problems as a too lean a main jet.

Another thing.....if you get a stutter with throttle response from 1/4 to 3/4 throttle.....this is usually a needle issue. If you have needles that cannot remove the clips to raise or lower the needles. You can use small brass remote control car washers.....#4 or #6 washers. Just slide them over the needle to the top against the needle retainer at the top. This gives you the same spacing as a needle with a removable clip. You should only have to add one washer....if that doesnt help.....then its a jet issue.

Okay....i'm done

eldar · « **Reply #10 on:** January 31, 2006, 08:49:39 AM »

Never thought about trying a washer there. I will have to see if that can be done on the 78 carbs. The 77s still had the clip positions.

Lumbee, look at the front fender. The part I am referring to is the back part that wraps around the back of the front tire. The earlier models have one behind and in front. UGLY!

dusterdude · « **Reply #11 on:** January 31, 2006, 09:58:31 AM »

eldar,the nighthawk guys on the cb750 yahoo group do the washer thing all the time.

ohiocaferacer · « **Reply #12 on:** January 31, 2006, 10:01:40 AM »

Quote from: dusterdude on January 31, 2006, 09:58:31 AM

eldar,the nighthawk guys on the cb750 yahoo group do the washer thing all the time.

Definately a must do on the nighthawks. I just serviced a 1983 Honda Nighthawk 700sc.....talk about cold blooded!! The washers help, but only way to cure them is bigger slow jets.

eldar · « **Reply #13 on:** January 31, 2006, 10:59:34 AM »

Well I dont have a highthawk darn it!

Would not mind one however butI still want to get my hands on a v65 sometime!
Well I have not noticed an issue with mine but I might try it anyways just to see what happens.

Lumbee · « **Reply #14 on:** January 31, 2006, 11:07:20 AM »

...just to be clear, my problem is not RPM related, but speed realated. That is, in lower gears the motor pulls strong up to 8/9k RPM, but on the interstate just cruising (50-60mph) the throttle seems to get "frothy". This is why I tend to think its air flow related. Also keep in mind this is not the bike in my avitar, but my chop:

http://pg.photos.yahoo.com/ph/marklocklear/detail?.dir=8c67&.dnm=740ere2.jpg&.src=ph

..the pods are "out there" compared to what they'd be on a stock bike, so theres lots of wind swirling around...

dusterdude · « **Reply #15 on:** January 31, 2006, 05:02:54 PM »

lumbee,you may be onto something about the air thing,i notice with mine it seems to run lean and when my gf rides on the back it seems to run just fine.food for thought

cd811 · « **Reply #16 on:** January 31, 2006, 05:24:42 PM »

I'm in ms. delta(dam near sea level)...
I wish I would have heard ohiocafe's advice month's ago

...
lumbee...I hate ya still got problems

...I like the idea of washers to raise needle...plus...ya might try my pod restrictor adapter...a short 1/2 pvc with an end cap glues on it,then drill hole in end cap and back of pod,then bolt together...resticts air flow...better than tape

...ya may have to consider a breadbox like I did

eldar · « **Reply #17 on:** February 01, 2006, 08:16:40 AM »

You can also get foam and stuff it inside the pods to restrict air flow. As long as the foam gets cleaned and is replaced before it gets old, you hsould not problems with it. Use some of the Uni foam.

Lumbee · « **Reply #18 on:** February 01, 2006, 08:30:55 AM »

...where do I get "uni foam"

eldar · « **Reply #19 on:** February 01, 2006, 09:02:08 AM »

You know the Uni air filters, some of that foam. You should be able to get somewhere in your area, some auto store and probably motorcycle dealer.

Lumbee · « **Reply #20 on:** February 01, 2006, 09:14:06 AM »

...i'll check my local shop...

dusterdude · « **Reply #21 on:** February 01, 2006, 09:43:54 AM »

Quote from: cd811 on January 31, 2006, 05:24:42 PM

I'm in ms. delta(dam near sea level)...
I wish I would have heard ohiocafe's advice month's ago ...
lumbee...I hate ya still got problems ...I like the idea of washers to raise needle...plus...ya might try my pod restrictor adapter...a short 1/2 pvc with an end cap glues on it,then drill hole in end cap and back of pod,then bolt together...resticts air flow...better than tape ...ya may have to consider a breadbox like I did

lets see a pic or even engineering notes or maybe blueprints too.

cd811 · « **Reply #22 on:** February 02, 2006, 04:57:36 PM »

went out and pulled pods off(yea, I went from breadbox back to pods)(as twotired says,eye candy

)...sure my pics suck but ya get the idea

...I said glued earlier but I remembered I had found 1/2 pvc male adapter and a end cap with female threads, so they just screwed together...

Lumbee · « **Reply #23 on:** February 02, 2006, 07:06:59 PM »

...so what are we looking at here Carl. Do you have filters inside the pods, then the PVC peices stuck inside that? That seems very restrictive...

cd811 · « **Reply #24 on:** February 02, 2006, 08:18:23 PM »

naw...it's just a regular k-n pod with just the pvc piece inside...yes it's restrictive...that the idea... and it's hidden on the inside so it's not noticable...as apposed to tape or ductwork

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Author Topic: just a note (Read 4738 times)

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