Orange n Black's 700

The spark plugs that I'm using now are #8's, so would it be ok to use #9's in the #2 and 3 cylinders. Copper fittings are easier to come by than brass so I may have to use the copper ones instead regardless of the ethanol/copper problems. Or I'll make something out of steel pipe at work. :wink:

 

Maybe I'll hi-jack Zookie's design, but have 2 separate pieces. :twisted:

 

Orange check out this web page for heat range #
http://www.ngksparkplugs.com/techinfo/s ... berkey.pdf

 

Well I installed side covers over the sides of the pods to deflect the forced air from the side. I used the chrome airbox covers, worked out well. Got the idea that this would help from Shooter's post on an earlier page.
Then following Waldo's advise, I installed #7 spark plugs on cylinders 2 & 3. If it ever quits raining and spawning tornadoes around here :roll: , I'll take it out for a ride and recheck the plugs.

 

Went for a ride Friday afternoon, still popping on the left side but not as much. Smoked a Harley, then headed home. Plug check is as follows, #4-tan,#3-tan, #2-slightly tan and #1-somewhere between white and tan. I believe that I can adjust for this without further mods. :twisted:

 

Finished....for now. :lol: I got the carbs adjusted and it runs great. Mpg is 40 so far and there's no problems with the cpvc intakes or glue.
Next years plans: professional paint job, springer front end and new rear shocks. :wink:
Meanwhile I'm going to enjoy myself riding the tires off!

 

How is the power of the dual carb setup compared to the stockers? I'm thinking about doing the same mod, but if I'm better off rebuilding mine I'm perfectly comfortable doing that.

 

There is plenty of power to spare, it has really surprised me. The only problem I ran into was more fuel/air mixture seems to gravitate to the center cylinders, so a plenium inside the intakes would surely work better. The real advantage with these carbs is the simplicity of it all. Easy to adjust, easy to sync, easy to clean and I only have to work with 2 carbs instead of 4. Sometimes less is more. :wink:

 

just a thought,but if u r getting more fuel to the centre cyls,would it b possible to have a straighter run to the outside carbs? i dunno if it is possible to run the carbs further apart,but what i was thinking is if they wer placed behind or slightly off centre from pots 1 and 4 with an angled piece leading off to pots 2 and 3.may not be viable because of the throttle linkage,but if it were poss,maybe the strater run to the outer cyls would compensate.

 

Your probably right, I'll give that a try next. Thanks for your input.

 

I'm back, with bad news unfortunately. After 3 months a problem developed with the intakes. After 40 miles the bike would start running like crap because of too much air from the rubber intake boots being loose. I thought that they were coming loose because of vibration and the smooth surface of the cpvc pipe not allowing the lip inside of the boots to lock on to the pipes.
After taking everything apart I discovered that the ends of the cpvc pipes had become soft and distorted. So what has been happening is after 40 miles exposure to heat and fuel, the pipes become soft allowing air to be sucked in around the pipes at the boots. :x
Conclusion: cpvc or pvc will not make suitable intakes, but I have learned a few things along the way. :roll:
Next I'll be redoing the intake design with metal instead or maybe I should keep things the same and just add a viagra pill to every tank of gas. :lol:

 

I won't say I told you so...page 6

 

Thanks. But I learned that even if the rails are the same lenght and the carb rail is dead center, doesn,t mean you'll get equal mix to both cylinders. My next attempt will direct more towards the outer cylinders. I'm going to use mild steel handrail pipe from work, after all its free.

 

Use copper pipe and group cylinders 1 and 4 on the same carb and 2& 3 together on the other. that way you would have the intake pulses 360 degrees out rather than the uneven pulses with your current setup.
It would be like a dual plane intake for a v-8 engine. you could also make a flap that opens at a certain rpm to boost the top end.
Longer intake runners boost low end torque.
Intake length is about 10 times as important as exhaust length for best performance.

Call me @ work and we can discuss it further.
330-630-0240 ask for Tom

 

Sorry I haven't responded for a while, having problems getting emails. The reason I paired 1n2/ 3n4 is because of the simplicity, lack of space, and I would most likely need bigger carbs if I went the other route.
The bike performed very well except for the fuel moving toward the center cylinders. I'm in the process of making new intakes now with the carbs attached closer to the outside cylinders to even out the distribution (hopefully). If this doesn't work I may go with fuel injection or fill it with bullets. :lol:

 

I got my new intakes made and installed. Next comes the testing and adjustments. I'll let you guys know how it turns out.
Here's a pic of the new intakes, they are made from 1-1/2 x 1-1/2 x 1/8 square tubing, 1-1/2 x 1/8 round tubing and 3/16 for the flange. Note that the carb mount is off center to send more fuel mix to the outside cylinders.

 

hope it works this time good luck

 

oh boy, are those steel?

 

Yes they are mild steel, but since the material is 1/8 thick, they're not heavy.
I'll have to come up with something for air filters since I only have 1-1/2 to 2 inches between the carbs and the frame. I'm thinking about the pancake filters people used to put on Triumphs.

 

So what are your plans for your old sissy bar?
You can PM me if you want to sell it...

 

My son-in-law just picked up an 86 Maxim 700 and he might need it, but if he doesn't I'll get back to you.

 

right on!

 

Update: I finished installing the new intakes and making the carb adjustments. The bike is running great.

 

How about some photos?

 

So after getting the damn thing running I had a little accident involving gravel, lost skin and stupidity. Only slight damage to the left forward foot controls. Still working out shifting issues, hope there isn't any tranny problems. Could be the spring not returning the shift lever or a bent shifter.
When I get that worked out I'll post a new pic. BTW It's been 2 weeks since the accident and I'm all healed up now, just in time for the neck spinal fusion surgery this Thursday. :lol:
I know what you may be thinking, but life ain't worth living if you can't do what makes you happy. :wink:

 

Orange best of luck to you on your surgery hope every thing works out for ya.

 

Was able to go for a ride today but was weird wearing a neck brace. :lol:
Bike is running great, shifter is working great. The pivot bolt and tube for the forward control was bent, straightened the tube and replaced pivot bolt with a new one.
Here's a couple of pics of the new intakes on the bike. I'll have to modify the frame rails a little to better accommodate the filters. It would be easier to change the intakes, but since they are working so well I'm going to leave them alone.

 

Update: Intakes have worked well except for having to wait longer for it to warm up(about 10 minutes) and some spotty throttle response when taking off from a dead stop unless you keep the revs high.
I think the answer lies in the size of the intake. I used 1 1/2 inch square tube for the main body, so I'll make some new ones out of 1 inch and see how it works. But it'll have to wait till March. Till then I'll just have to be content reading about everybody else's adventures. 8)

 

I've been off work since Sept. recouping from neck surgery. Neck is fine but back was giving me hell. Went to the doctor today, seems my riding days are over. I have 5 bad disc's in the upper back and 2 in the lower back along with a cracked vertebrae. 8O Will be filing disability and bike will go up for sale come spring. :cry:
I'll hang around here though, your not getting rid of me that easy. :wink:

 

Man, that sux completely. :cry:

Hope they have not talked you in to surgery. Avoid that if you can. The only thing that ever gave me relief for a bulging disc and cracked pelvis was Rolfing. 8)

Hope you find relief!

 

I've already had 2 surgeries,they help for a little while. What the Doc's don't tell you is that it puts more stress on the other disc's resulting in more surgeries. :evil:
The Doc wanted to do another surgery, but I turned it down cause I'm a high risk patient. So its pain pills till they refuse to give them to me, sometimes they work - sometimes they don't.

 

Orange-n-Black,

I have been following this thread for months. The twin carb mod is one I want to do. Just reread the thread and maybe I missed it which carbs did you use? Are they the ones that CycleX sells for the XS 650? Or were they the ones for the CB 750? Whichever, did the jetting work OK as supplied or did you have to tune?

Thanks!
MW

 

I got the carbs for the XS650. They are Mikuni 34mm which are the same as the kit for the CB750 minus the intakes which wouldn't work on my 700 because the Honda has a stepped head design.
They are working on a kit for the CB750 DOHC which would probably be better, but then there's the head design problem with the intakes.
The kit is the way to go because you get extra jets, throttle kit and boot rubbers which I used to attach the carbs to the intakes that I made.
The intakes worked ok, but had a little issue taking off from dead stop. The intakes were made from mild steel tubing 1 1/5 x 1 1/5 x 3/16 with 1 1/5 x 3/16 round tube for the inlets/outlets. I believe they would work better if they were 1 1/5 x 1 x 3/16 with 1 1/5 x 3/16 inlets/outlets. Just haven't been able to do anything lately.
On the other hand, I just remembered that after making those intakes I changed from straight pipes w/drag pipe silencers to aftermarket mufflers because of the noise. So the problem may be the jets. DOH!

 

I really appreciate the information. Had been considering straight pipes with baffles but will stick with mufflers...

The plan for my bike is to make cast aluminum intake manifolds like the CycleX manifold for the C750. Planning to join the intakes with a balance tube to hopefully even out the fuel distribution to each cylinder. Will definitely make the manifolds assymetrical with the carb moved outboard like you did on the latest version.

It is hard to tell from the photo on the CycleX website, are the carbs a left and a right?

 

Unfortunately not, but since they are on the outer side of the backbones the chokes are easy to reach. The throttle cables attach to the top of the carbs and there was just enough room between the carbs and the tank.

 

Update: I removed the 1 inch collar between the intakes and the carb mounting flange,thus moving the carbs 1 inch towards the motor. That gave me more room for filter clearance issues.

Still had filter clearance issues, so I put some rubber plumbing couplings on the carbs with 2 pvc elbows into a tee with 1 pod attached under the seat so it won't have problems running in the rain. This setup helped the start up and the take off issues some but was still a problem.

After thinking about it a while, I went to the hardware store and bought a 3/8's steel rod and cut it to 12 & 1/2 inches long. Opened one side of the YICS port and blocked it off with the rod. Sealed the port back. Problem solved. Starts easy, idles well, takes off without hesitation and runs great throughout.

Reflection: 2 carb mod can work great.
Requires blocking off YICS to insure proper fuel/air mix to cylinders because YICS was robbing too much mix from other cylinders.
Requires trial and error on intake design and using proper materials. Pvc was useful in determining a proper intake design, doesn't last long, but long enough to check for even cylinder burn and cheap too. Aluminum or cast aluminum is the perfect material but requires tig welding.

The bike has been painted a new color. It's been painted a copper metal flake with 2 tone red pin stripe decals. I'll post pics soon.

 

New paint pics.

 

diggin it!!

what windshield is that?

 

Thanks, Memphis Shades for a Virago.

 

Just finished reading the thread. I was out on the bike a lot this summer and here in NY you gotta ride when the weather is right. With only 6 rain days all summer, i have been doing plenty. I am real sorry to hear about your back. I am out of work due to a back injury as well and its no fun. I love the bike and the wild carb setup. Hope its working how you wanted it to. So no more riding really? You are done? Hope there is still some hope. Paint looks better in my opinon. Later.

 

The carb setup works real well now that all the bugs have been worked out.
Yes my riding days are over, I spend probably 50% of my time laying on my back and sitting is starting to get uncomfortable.
It took me 4 months to get the bike painted and back together. That only would've been a week when I was well. Will be listing the bike for sale soon. Pity, I won't get much for it after all the time and money that went into it. But it was fun. The fork seals have started to leak and the brake lines are old.
The paint has a bright metallic color in the sunlight, but looks gold in the shade and a little greenish tint. It's rattle can Rustoleum BBQ Grill enamel with clear coat engine enamel on the tank so gas won't eat through.

 

Man. I am sorry to hear that. I guess you don't sleep much either. It's 3:11 am here and as usual, I'm up looking at bike stuff unable to get anywhere near comfortable enough to sleep. I can't imagine not riding. I mean damn. I hope you ate taking it ok and can get through it. I will keep looking for your posts and wish ya the best of luck.

 

Yeah the pain gets bad and keeps me up late sometimes. A hot bath helps, wish I had a jacuzzi. Hope you get well soon.

 

Yes. It sure does. And ice in my case. Haha. Thanks brother. You as well.

 

How do you like those right side up clubmans?

 

I like them, but I wish I had a pair of Vintage Short Stack. Just didn't want to go through changing the brake lines at the time and the price for the bars had something to do with it too.

 

The only thing I had to change with the clubmans turned up was the clutch cable. Got one for a Virago that was about 2 inches longer.

 

Hi orange n Black. I have not posted for a while but I still look in to see what others are doing in the XJ world. I am very sorry to hear about your back problems. Was this the result of the accident that you had on your XJ or is it just wear and tear on the spine bones. Not being able to ride must be a total bummer. Have you thought about building a trike using an XJ as the donor bike. Something like this and some lateral thinking may get you back on the road again. Any way I hope that things get better for you as I always enjoyed reading your posts and the ups and downs of fitting a dual carb setup onto a 4 cylinder motorcycle. Get well soon.

From Bob
Tasmania Australia

 

Bike looks great! Sorry to hear about your back problems

 

Thanks guys, the back problems are from degenerative disk disease and a life of hard physical labor. The last thing I want to do is get rid of this bike, I can't work on it anymore and my body can't take any jarring. Time to let it go and let someone else enjoy it.
I may be a cager from now on, but I'll be a 2 wheeler in spirit.