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

Hey guys, this bobber took me 6 months to build but its finally done, enjoy the photos. However, the jetting is off. It seems to produce a bobbing sound on higher RPMS. A buddy told me to ride it with the choke pulled, and i must say, it helps alot, but does not entirley puts the bike to PAR. What seems to be the problem? should I get smaller Main Jets? hence it seems to be having a problem providing enough air? take into consideration that I already have 4 filter pods, and a custom open 4 to 2 exhaust! so shouldnt i be okay on the air flow?

thanx and enjoy
Doc
The Start










The Finish







Harley Davidson Controls


My Toys

 

I Like!

 

very nice job...

 

Bike Looks awesome. Where did you get that front cover thats below the headlight? I've been looking for something like that to cover some wires I have that are exposed after I did a headlight a guage mod. Thanks

 

I like the look too...but I would figure your problem running LEAN (too much air, not enough fuel being drawn up into the air stream), mostly due to the pods although the free flowing exhaust won't help much either. Did you rejet the carbs? You'd need to go up many jet sizes to even hope to compensate for all that airflow. Did you rebuild them at all? How do your plugs look? What about at higher RPM?

Do a search for pods on this forum to get links to what people think of them...and more importantly for you, how to possibly make them work. You don't want to be rebuilding an engine in short order because you holed a piston. These bikes can SCREAM when they're lean, but they won't run like that for long.

 

the grill "cover under the lamp" came with the bike. I just painted it... it used to be chrome. its off of an 1982 maxim xj1100, the part number is 10M2312200. but they are not available any more. try to ask around on here to see if anyone has one that would sell to you.

 

ManBot13,

I rebuilt the carb:

Pilots are 47.5 (stock size but new), considering stepping up to 50's

Mains are 0.138 (stage III dyno jets), I also have 0.128s and 0.124s

I had put 0.190 Pilot Air Jets, which the instructions from DynoJet had said to replace regardless of the stage upgrade, but the guy at the shop who had tuned the carb, had said that it was running too rich?!!!! so he took them off and put something else (i dunno what he replaced them with)

Note: but hence it rides smoother with the choke pulled out, doesnt that mean that its running richer on gas. choke adds air, righ?! so if I put smaller mains, providing less gas, that should even out the ratio, no?!

Thanx...

 

Again I'm not too familiar with the 1100s, so I'm just going to assume it's similar to my 750. The "choke" is actually an enrichment circuit, so it adds more fuel, not less air.

Either way, if you need choke to run right then you are running too lean. There is a lot of discussion about pods on the forum, and since I don't have them or an 1100 i can't give you any more specific advice, but from what I have read, you can reach a point where there isn't enough air flowing through the air circuits to pick up enough fuel to mix with the air in the venturi.

It looks like you didn't leave room for the airbox, but putting it back in is the simplist solution to tuning (you'd still need to do some tuning for the exhaust). You could also get a set of larger slide carbs. The problem is that these engines didn't have any problem breathing from the factory.

 

Now that is a BOBBER I'd want! Nothing against them normally, but I like this one!

I really like how the exhaust and parts of the engine are blacked out.

Also the stock XJ style tank really does work with that seat and the rear fender.

 

I too was curious about the grille deal and just purchased one on ebay for $12

 

I too was curious about the grille deal and just purchased one on ebay for $12

 

What happened to all the left over parts?

 

stunning...I love it AND THE PODS TOO!!! Ride the piss outta it and be careful, especially with that brake light only on one side...

 

RE: Chokes.

A "real" choke restricts airflow, not adds it. That's why it's called a "choke."

The "choke" on your bike (and yes, it's the same as the others) is actually an enrichening circuit, which dumps more fuel to the carbs. Since it provides the same basic function as a choke (to enrichen the mixture) they call it the "choke."

That and "enrichment circuit" wouldn't fit on the label on the handlebar cluster.

You might want to do a forum search on "pods."

 

Very nice.
Vary plain looking.

You could eliminate the External Wire running down to the Tail Light.
Drill 2 Holes.
Feed-in some Thread.
Vacuum the Thread out the Bottom Hole. Pull that wire through.
Grommets or not.

If you have no plans for the two vacant holes where the rear Footpegs would mound.
"Finish" the vacancy.
Something. Anything.

http://www.google.com/imgres?imgurl=htt ... 29,r:0,s:0

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Sweet, I like the clean look. It would look better next to mine in my garage. Sounds a bit lean, time to remove the carbs and put new jets in. Then tune. Wish I cOuld tell you what jets but my bobber is a 650.

 

thanx for the support fellas...

ordered bigger pilots and mains... will put em on and test it out till its right...

and Mlew, you dont wanna know about the left over parts ;(
trashed it all, the bike was such a junk, all the parts were crap anyways

 

Keep us updated on the jetting bike looks great!!! Clean minimal

 

If you are running Pods, ... BEFORE you start the experimentation with various sizes of FUEL Jets ... MODIFY the Intake Horn to ALLOW the Atmosphere Orifice to be ISOLATED from the Turbulence of the Intake Air Stream.

Fabricate a "Plate" that will fit over the Atmosphere Inlet at the Top of the Intake Horn.
Seal it from the rushing volume of AIR passing-over it.
Cover the Orifice preventing the Vortex from having any effect upon it.

Drill a Hole to Vent the back of that Orifice to Atmosphere.
With the NEW Vent away from the VORTEX, ... Atmosphere will not be adversely affected by the Vortex.
AIR, ... Needed to ENTER the Orifice to supply the AIR JETS ... and ... let the Diaphragm Rubber collapse to raise the Needle Jet will be supplied.

With ATMOSPHERE at the Orifice.
>> There will be an ample supply of fresh air to surround the Emulsion Tube and be drawn-up INTO the Venturi.

The Mixture is suddenly going to be far less LEAN as a result.

 

Rick nobody knows WTF you are talking about without pics fella

 

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?

 

VERY NICE! I love the handle bars and especially the headlight. It gives it a 'bulldog' look. That's what I was shooting for. What kind of headlight is it? Is it stock?

 

WOW! that is perfect! i like how simple and minimal it is, yet nice and a bit mean looking. what did you do to make that exhaust? you should put some photos up on how you made the exhaust!

i really like this, and i hope you dont mind but i might borrow some of your ideas for mine. this is the first one i have seen that i want to try.

 

sweet ride

 

Thanx guys,

NewKid510 and 2sluggos: I made the handle bars myself... and the head light is stock.

Kentownsend: the headers and the the y-sections are stock, I only build the exhaust from the y-sections ---> back. just go to Auto Zone and buy some exhaust tubes (any size you want, mine are 2.5" I believe) and buy a couple of adapters that will fit the new tubes on one side - and the mouth of the y-sections on the other. Get some clamp rings, clamp them, then wrap it with header wrap....

Since the pictures I have also made some velocity stacks and tuned it with stage III dyno jets... it is fast... and it sounds meaner than hell...

 

old thread, but great looking bike. clean and well done. nice.

 

I know this is a relatively older thread but I have a question. I noticed the handle bar controls are very similar to Harley Controls. They have the seperate turn signal switches on both sides . I want to do this with an XJ650. I have the larger 1" bars mounted with everything looking great, I just can't figure out how to wire it up to the XJ's wiring harness. Any insight?

 

Very nice looking bobber!