1978 kz750 smoke

I am 19 years old and don't know everything let alone have micrometers or bore gauges. The reason why it is smoking was because I tor a valve seal so it was pulling oil in. I replaced it and now no smoke. I believe that the popping sound I said it had might be because of the points/ stator thing on the crank case and also might have to replace the cool pack and wires. I am going to go throught the carbs again and do anothe bench tune. I

Is the intake I have ok or is it bad

The CV carbs are really sentsitive to air filters and exhuasts, so getting it to run right through those short drag pipes and intake might be a challenge. If you have cleared the smoking the I'd look to the carbs next, clean them out and look at the jetting and needles. They might have been set up before, but unless you had it running good then you don't really know.

That bike is really cool and you have done well getting so far.

Soxx4u wrote: Ok. In my video I give it a light rev and it smokes is that because the rings are new or might I have damaged a valve seal

OK... so you have replaced the bad valve guide seal since this .mov?
www.kzrider.com/media/kunena/attachments...32D-7AF86A21C415.mov
I'm sorry I didn't review the entire thread but are the carbs stock?

On another note:
I helped a buddy run a 2 x 2:1 exhaust with a single, side draft, 44mm Mikuni on a 900 once upon a time... it was not an easy task to get it set up right and to be honest, except being different and looking cool, it never ran any where as good as it did with the stock 28mm carbs.

Yup.
Steve

I cleaned the carbs throughly and now it doesn't hessitate as much as it did upon acceleration it's still there though. I don't know the size of my carbs the only thing I found was a 120 on the butterflies. I live in Denver co so elevation is 5280 ft. I don't know if my jets are a problem cause when I'm on the gas wide open it runs but when I cruize it hesitates and that where I get the popping action

Tyrell Corp wrote: The CV carbs are really sentsitive to air filters and exhuasts, so getting it to run right through those short drag pipes and intake might be a challenge. If you have cleared the smoking the I'd look to the carbs next, clean them out and look at the jetting and needles. They might have been set up before, but unless you had it running good then you don't really know.

That explains the popping, hesitation and poor running. It's probably way too lean. The stock BS-38 carbs came with 45 pilots and 125 main jets. God only knows what this thing would need. I would definitely go up to 50 pilots. The needles will probably have to be shimmed to get any kind of decent off idle response. Some needles have adjustment slots.

Soxx4u wrote: I am 19 years old and don't know everything let alone have micrometers or bore gauges. The reason why it is smoking was because I tor a valve seal so it was pulling oil in. I replaced it and now no smoke. I believe that the popping sound I said it had might be because of the points/ stator thing on the crank case and also might have to replace the cool pack and wires. I am going to go throught the carbs again and do anothe bench tune. I

First is to set the fuel levels with a clear tube, bench tuning is basically a waste of time.

The good news here being it seems you are way out your carb jetting, although setting these up is time consuming and one rarely gets it right first time, or 3rd or 4th quite often.

It is nice to have a bike that runs like a bag of shit, then making a few minor changes and then it comes to life.

Sometimes feeling the change is important, so after checking/resetting your float fuel levels with a clear tube U bend, try lifting the needles for the main jets, shim with some tiny washers. If it gets better or worse then tune accordingly. Even if you make it worse, that is good as you are narrowing down the problem.

Better than trial and error is someone to point you in the right direction, the 750 twins are quite rare here so good luck. Generally, open filters for a cv carb is upjetting and lifting the needle as a minumum, bigger pilot jets likely and if you are keen changing the air jets and lots of other tweaks. Getting it 90 percent right is the easy bit...

With that intake system it will be damn near impossible to tune it right. If you don't believe me, try with it off. CV carbs are very forgiving of elivation changes. That's where they shine. Custom intakes and exhausts create the problems. What you have is not engineered for performance. More like a tractor or lawn mower. :whistle: Looks cool though. :woohoo:
Steve

I took that intake off and it runs a little better still some pop but a lot better than it was. Now here is the big question should I go with pod filters or just rock it with nothing on there I do not want to go to stock intake

Pods, don't go naked. :ohmy:
Steve