SINGLE CARB MOD

Zookie,
I sure hope it runs with that carb on it, even if there's a loss of power, it is still a great mod and one for the books.

 

http://www.powderbuythepound.com/S-and- ... INKLE.html

 

Saweeeet!

 

Mean setup... Love that finish

 

i think there will definitely be a loss of power on the top, because of the way the carb runner intersects the rail perpendicularly, however i really dont ride it up there so its not a huge issue. i think low-mid will be nice, maybe even an improvement from the long runners. maybe not. it would be nice if i had a "before" dyno chart to compare to. i dont.

it will be great if i get an improvement in efficiency. i think it will do better on that front because carbs work much better when there is a continuous draw on them rather than a pulse. the fuel droplets will be marbles compared to bowling balls i think.

 

Hi Zookie Just wondering how the single carb mod is going

Bob

 

i got back to CT today, spent a little time on it but not much. manifold and carb are bolted up. it starts and runs on choke only and at 5000 or more rpms. it fouled plugs pretty quick and spewed unburned fuel out of the exhaust. here comes the jetting from scratch process. i am going to try and get an assortment of jets tomorrow. also, i need to adjust the float level and check the valve because the carb is dripping fuel out of the mouth while sitting with the engine off.

even in the terrible state of tune, it was VERY snappy. rev limiter was used a few times by surprise.





here is my average leg placement while riding, with the new carb in place:



and here is the unhappy display of screaming rpms on one cylinder and unburned fuel spewing everywhere from the exhaust:

 

Hi Zookie. Looking good "Its Alive" I have sent u a PM catch u later

Bob

 

Just tell everyone it's a two stroke for now! 8O
:twisted: :twisted: :twisted:

 

I hate to say it but the only thing that makes sense in my mind on a 4 banger is (Fuel injection to each cylinder independently) now boy does that open a can of worms to figure out eh? Be a good topic to sick those guys down at ITT on to create, eh? )))) grunt007, XXJ750R Seca, still trying to erect the old gal but I now have my Harley exhaust pipes to go on her, problem is they are not off of Sportster but off of shovel head probably. They are still going on, I like their look. Only problem is I will have to compensate for going from 1 1/2" pipe to 1 3/4" opening on the muffler! Good side, they are built like a TANK! Also, they weight so much that I shouldn't have any trouble getting traction off the line )))

 

Hey grunt, are you referring to this build?
http://xjbikes.com/Forums/viewtopic/t=29313.html

 

Yeah, already been done, man.

 

EFI would be GREAT. but i got this carb for free, and i dont want to spend large amounts of cash on a bike i only have for the purpose of saving money.

if not for the financial end of things, EFI would be done already. its hands down the BEST.

as for my carb....i hit a MINOR setback today. jets are not the standard keihin style, and people want A LOT of money for them. so........i will need to break out the drills and make my own.

 

well i dont have any pictures today, but i did get it to start and idle for about a full minute before a plug fouled. i went through about 20 pilot jet sizes today.

its still too lean (i think). it will only start with choke or a shot of ether, and once the choke is off it will die out, or if the choke is on it will run and smoke and foul plugs.

the main jet is very very lean as well, once the throttle is cracked more than 5% it dies (no smoke).

i am closer but still very far away.

it is VERY responsive though (with choke on...)

 

Bah, youll have it done in no time

 

Which plugged fouled Zookie

 

Zookie I think you would have better results if you shortened the runners to the ports and placed the carb on the backside of the collector between carbs 2 and 3 (facing towards the seat). I'm thinking that the fuel mix may be destabilizing due to the long length of travel and the upward bend to the collector. Just a hunch, but something to try if nothing else works. :wink:

 

Hi orange-n-black I think that you may be going in the right direction.
zookie says that it runs lean and needs lots of choke to get it going.
Then after a while it blows unburnt fuel out of the exhaust and fouls
the plugs up. I am thinking that some of the atomized fuel is
condensing on the intake pipes. This raw fuel then pools in the bottom
of the long pipe that has the 4 intake pipes coming out of it. This fuel
builds up until it is high enough to get sucked into the cylinders fouling
the plugs and stopping the motor.. This is just a theory. As the fuel droplets come out of the fuel air vapor mix the bike seems to be running lean and need more choke but this may only make things worse with more fuel being sucked into the tubes. The raw fuel pools
and the motor sucks in all this raw fuel and makes it look like it is
then running rich. Putting the carb at the back with shorter and more
direct pipes may be the answer.

It may be that the carb is not working properly. It will be interesting
if an answer is found to the problem.

 

all of them

i will be working on it a little more today 8)

 

Ride around the hood and kill the mosquitos :twisted: