Orange n Black's 700

Orange just curious what size jets are in your new carbs

 

pilot-15, needle jet 159-p-6, needle-6f9, throttle slide-2.0, main jet-180
Also came with extra pilot-20 and main-190.
What's your opinion on the cpvc intakes?

 

Do a test place a small piece of cpvc in gasoline and see if it degrades. If it does not then you should be ok.

 

I dont have a clue about the cpvc material but I bet if you called the manufacturer and spoke with an engineer they could help you out you would be surprised how helpful some of them can be they love to talk about new applications for their products. I ll tell you why I asked, Seems to me the carb set you have now is setup to feed a cylinder thats 325cc and the engine is only asking for half that amount because the cylinders are 180 degrees apart. Think of it this way only one cylinder draws on the carb at a time.

 

i Have seen several bikes with pvc intakes i think if it does eat it it will take a long time. I would be more worried about it eating the pvc glue and causing vac leaks. All you can do is try if it does start to eat thru you will have a great mock up to make a metal one

 

Thanks guys for your responses. I looked on google for more info on the cpvc, all I could find out is that it is resistant to chemical corrosion and contamination and it is made of resins of a petroleum base. I think cutlass was right about the glue being more of a concern.
Waldo, this same system is used on 750's with success, so I'm sure it will work on my 700 with some adjustments and maybe some jet changes. Keep in mind that originally there was a 33mm carb for each cylinder. That would be 1 33mm carb per 175cc's. But like you said, some 32mm carbs might be enough.
I know there is a restriction problem now because if let the bike sit with petcock open for 5 minutes, it will crank and run for about 10 seconds (burning up the fuel in the bowls) then die. 5 minutes later, same thing.

 

run bigger diameter fuel line, I had to with my CR125 carb too.

 

My petcock doesn't shutoff so I had to put a inline shutoff after the petcock. It's 1/4 inch which is all I could find, from there the line goes to a inline filter which is also 1/4 inch, then to a 3 way splitter which is 5/16 inch, to the carbs.

I removed the inline filter and ran 5/16 line to the splitter, then to the carbs whith same results. This is why I was considering running 2 separate petcocks and lines. Here's a pic from the CycleX site of their setup.

 

Update: I converted the vent line on the back side of the petcock into a second fuel line. Now I have to get new gaskets for the petcock to re-assemble.
My son-in-law knocked over the fuel tank messing up the paint, now I have to repaint. :evil:

 

Re-assembling the petcock tomorrow and installing. Then I'll crank this thing up and go from there.
Purchased this headlight and waiting on the shipment.

 

Update:
1. Headlight installed and working.
2.Carbs, petcock, filters, shutoff valves and lines are installed.
3.Cranked up and runs well at idle.

Will take for a ride sometime this week for final adjustments.
Then I'll make a video if I can figure out how to upload.
It is a happy day. 8)

 

Throttle response is smooth, low and medium rpm range operates very well with acceleration to spare. All cylinders are working well,but on the rich side. No backfiring, but will have to put on mufflers because its too freaking loud. How loud? Small children run screaming when I drive down the street, went around the neighborhood and the wife thought I was still in the driveway from the noise.
Came home from work to find the petcock leaking yet again, so I'll have to fix this once and for all before testing high rpm operation. With going back to mufflers, I may have to re-jet since its already running rich. Only time will tell about the cpvc intakes and glue, will update. Here's a couple of pics for those pic crazed people on the site. :lol:

 

Hi Orange N Black Just read your rebuild post and I found it to be very
interesting. You have done a good job with an interesting carb mod as well. Going for two carbs meant for a 650 twin
was a good move and when you have them jetted up properly I think
that it will run really well. You may still have to have them synched with
a set of gauges or something so they are both pulling together properly. It makes a really big difference. Your build is really interesting and I am looking forward to the next post.

I dont think that fuel attacks the type of plastic that you are using for
your intake tubes but as people are saying the glue may come unstuck. Soaking some in fuel should reveal what will happen.

Bob

 

Thanks Bobe, the big problem I'm having now is with the petcock. I'm going to replace the petcock with a high flow aftermarket type as soon as I can. Of coarse this means more modifications. :roll:

 

This is the hard part of modifications. You do something only to find that you have to do something else to support the first thing that
you did and around it goes. Great post and catch u later.

Bob

 

Slight manifold problem.
As you know I have 1 carb feeding cyls. 1&2 and 1 carb feeding cyls. 3&4. Although the all the manifold pieces are of equal length, most of the fuel/air mixture seems to be moving towards the center of the head. For example, spark plug results for carb 1(cylinders 1 & 2) are, cylinder 1 is whitish while cylinder 2 is sooty. Plug results for carb 2(cylinders 3 & 4) are, cylinder 3 is sooty while cylinder 4 is tan.
I believe that I'm going to place a plenium inside each manifold to divert a larger percentage of fuel/air mix to the outside cylinders. Whats your opinions on this?

 

I've also seen balancing "plenums" between carb banks to equalize the vacuum (similar to YICS but larger). I think it will be more of a chore to get the 2 balancing "flaps" just right than to go back to 4 carbs. Are the inner/outer plastic tubes the same temperature? I would think plastic would be less affected by temperature, but maybe there is an issue with vaporization. Maybe if the 1/2 and 3/4 manifolds were longer (more like "sanitary Y's") it might flow better, but then the carbs would be further back...

 

I agree that a (Y) shape would be better. Maybe its time to break out the brass pipe, cut 2 pieces with a 45 degree elbow into a single stem?

 

Orange have you thought about running different heat range spark plugs in the 2 center cylinders say go one range hotter

 

I've also seen some parallel twins with a single carb and soldered copper manifolds. Don't know if the selection of copper Y connectors is any better than PVC but might be worth a look.