CHECK IT OUT... My 82 XJ 1100 Custom Bobber is done

Now that's what i call a bobber looks very nice. And you picked a good bike to do it to. The bike needed a makeover

 

Next week I am going to do what Rick said. I forgot about that thread. I may take some pictures to post. I have a set of trashed carbs so I wont ruin a good set. Currently running velocity stacks that I made, and stock jets, Obviously running lean.

F.H there is a passage at the top of the intake. the theory is that the rough air entering this passage causes it to run lean. It sounds convincing. I haven't read the thread on it in a while, but Rick can explain it better.

I personaly wouldn't recomend drilling a hole in the carbs unless you have a set laying around, but I am not as formiliar with it as Rick. I think I am going to try it out on a set of carbs I have though.

I have an extra set with a broke float pillar. Wish there was a good fix for it.

I really like the colors you have gone with, and the clean look.

Mine




Did you make those handle bars? There sweet.

 

My Theory is NOT that rough air enters the Atmosphere Port.

My experiment, ... with a single carb hooked-up to a Shop Vac showed the Intake Air rushing past the Atmosphere Port >> robs the Air from entering.

Plus, ... when the Throttle is opened wide, ... a Vortex forms and swirls into the Carb.
(Thereby ::: Lowering the pressure at the Atmosphere Port ::: Causing a Vacuum to form. Reducing the Air Pressure:
++Preventing AIR from being supplied to the Main Air Passage.
++Causing the Diaphragm Piston to rise erratically or restrained.

ALL contributing factors to a Lean Condition JETTING would not correct.

 

Okay... I've had it with the stupid tunning on this bike, i just cant figure it out.

Does anyone have an idea or a common set up used on the 1100cc for the carbs to suite 4 individual air filter pods, and a 4 to 2 exhaust. what size jets are people using nowadays with such a set up like mine?

thanx

 

What I would do, for what its worth. Try the smaller of the stage 3 jets, and hopefully you have the stock air box to carb boots. Put those in place of the rubber that came with the pods if you can and give that a try, it couldn't hurt. They will act as a velocity stack. I didn't change my pilot jets, just color tune.

To run pods on your bike successfully, you have to be able to figure it out, no 2 bikes are the same, and only estimate advise can be given.

Bike looks nice btw, its a monster.

 

Look under the forum xj4ever in the carb section he has a good starting formula for pods and exhuast. I would start there and see what happens. but like other posts have suggested you have to make sure the valves are adjusted right or it is all for not.

 

Here's the Photos of the ATMOSPHERE VENT BYPASS

(These are MIKUNI ... HITACHI's have a Vent here too. Hitachi's do not have the Air Jets situated within the Horn.)

 

that picture tells it way better Rick... thanx

but hence this is my only set on carbs, Im gonna try and get the best result possible by swaping out jets, and if it stays running Lean on HIGHER RPMS, then I'll consider ricks theory... sounds very convencing, but i just dont like modifying things like that right away

thanx for the advice Rick

 

This is what I did to my XJ1100 these are muffler reducers I used to move the pods back it helped the air flow to the ATMOSPHERE INLET because the pod Gaskets where covering part of that ATMOSPHERE INLET when mounted directly to the carb.

 

Awesome Job !
Did you balance the driveshaft after welding it??

 

what is holding the reducers onto the carb mouths?

 

IF there is enough room, drill and tap (preferably some small pipe thread size) so if need be you could plug the vent holes later.

 

Has anyone figured up how any cfm goes through these carbs because if your basing your theories on using a shop vac you might might want to redo your experiment

 

Pathebert, those also would serve as a velocity stack, Any length between the pod and carb will help straighten airflow into a stream. Reducing turbulence, rather...increasing velocity.

 

Today I'm gonna make me some velocity stacks outta black PVC pipe... its cheap, smooth, and can only benefit. I have a feeling its gonna actually fix my problem.

And correct me if Im wrong please,

I dont wanna vent the orfice just yet because from (mid to high Range), the needle kicks in. So when the slide rises (allowing the needle to bring in more fuel), the air behind the rubber diaphram is forced out the oblong opening at the horn, adding to air coming in through the intake. Thereby, balancing out the fuel/air ratio once more as needed.

I agree with Rick regarding "VENTING the ORFICE will decrease terbulance and allowing more air to enter the MAIN AIR JET". But that will only benefit the performace mainly within low to mid range, right!

the whole point to to have the bike running up to PAR through out all gears and all ranges.

 

Here are the VELOCITY STACKS I made today, from some parts I picked up at The Home Depot... I went in thinking of an all back PVC pipe, but I ended up with some steel sleeves too, which look great! Will keep you guys updated on the outcome after another round of tuning...

 

The muffler reducers I used I bought at Oreilly's auto part and they fit very tight after a little fileing I used pieces of a bicycle tube streched over the end tapped the reducers on to the end of the carb folded the tube to seal the connection and clamped it.
My reasoning was what streetbrawler750 said it not only kept the pod from blocking the top vent but also gave the air coming thru the pods time to straighten out.

 

It looks like your on the right path F.H.

 

And it worked? I haven't really heard anybodys feedback from trying it. Hows it runout?

 

hey what bars are those by chance?