pod questions?..mikuni 33...?....81 maxim 650....85 700 engine swap ..wiring...chopped bobbed

So im looking for help
If you see my pics im running straight pipes to the tips in the pics i posted.."minus the girlfriend pic" ...no muffler its open all the way 2 into 1 on each side...i have a mikuni 33 with stock everything and pod filters on an xj700 engine...
Could i get away with just changing the mains possibly?
Just got these carbs off ebay finally all clean and ready for jets?

 

with CV carbs, the airbox provides some restriction to the inlet side, acts like a power assist to lift your throttle slides. Ditching the airbox usually requires a larger hole drilled to the diaphragm vacuum chamber and softer springs. Try cutting 1/2 a coil out of the springs, fit a drill bit into the existing hole to the diaphragm and use a bit one size up. Welcome to the frustrating world of pod filters. Or - put the air box back which will be less trouble.

 

Hmmmmm...?

 

...and read the Information overload hour, as I previously told you

 

This is backwards, cutting springs makes them stiffer. Softer springs with the same diameter wire have more coils. Hard to explain the physics (more coils equal less force to compress as you're twisting the wire less) but it's a common misconception that cutting a spring makes it softer.

 

Yah i was thinking that too
Like lowering a truck the old fashioned way
Cutting the springs stiffins up the ride

 

when you assemble the springs they are a pretty good squeeze to fit under the caps, essentially a preload. Cutting some off will be easier to fit the caps, less preload. This is recommended by any commercial stage III kit which doesn't supply replacement springs.

 

From what I see.
Pods are going to be the least of your worries. You won't be able to ride fast enough for them to be an issue.

As you have removed the outer tubes of the back bone. That long fork is going to twist and flex that frame without mercy. Don't expect any handling or control out of it.

Bare framed hardtail? Give the GF my condolences!

At least you got one thing right. That bike is definitely going to dish out the punishment. ON YOU!!

 

Guess i didnt see or remember youre " previous"

Lol ....thats what welders and shocks are for...

 

You dont like the chop..ghost..?
Its larger diameter tubing than stock..i have rode it and there is absolutely no issues with twisting...

 

I don't like poorly done chops!!
Show me a pic of the full back bone and welds at the neck. I still see some serious flex in that frame.

Larger diameter does not necessarily mean thicker wall! The thin wall tubing of the factory frame leaves a lot to be desired. Hence all the extra triangulation and support. Most of which you have removed.

~Ghost

 

What Ghost speaks is the truth. The unmodified frame was relatively flexible already, and you took out a major component of the frame structure. Even wall thickness and tube diameter is a small component of frame siffness; geometry and load sharing matters too.
The concept is sound, but the execution does not look adequate. Cool is cool, but cool can get a fella killed if done wrong.

 

Well fellas i understand your concern....but before you hate on me for the chop its not my work i have two other full frames untitled that i have planned on fabricating a sweet rearend with..lol..
im not planning any long road trips soon trust me im not stupid
it rode fine with the 650 in it....
i put a 700 from an 85 and all the guts into it...just waiting for jets for my carb..havent rode it since removing the other engine the 700 may twist the shit out of it i dont know yet....any suggestions on the current design instead of telling me how crappy it is?

 

Any suggestions? Sure!

 

Smartass

 

You may not be asking the right people... this forum is more focused on stock bikes. Perhaps for frame modification, a chopper forum could provide more info. Don't quit this group, though! All the info on earth for everything else xj is here, just have to supplement it!

 

http://blog.jpcycles.com/2010/06/motorcycle-frame-geometry-made-simple-how-your-motorcycle-handles/

http://www.google.ca/url?sa=t&sourc...ke.htm&usg=AFQjCNH-aFhmBdoclztGElCcgT5wDsxMog

 

Cool... thanx matti...

 

I have a vintage brit bike and frequent a forum specific to it. Whenever someone asks if it is sacrilege to modify this or that, the usual response is that it's your bike, you do whatever the F#$% you want. In 1982 Yamaha tried to overtake Honda and upped their production numbers, showrooms had 1982 Yamahas for many years. I personally bought a XJ650 Turbo new in 1984 heavily discounted. Almost 30 years later these 82 Yamahas are still plentiful and cheap (there are exceptions, turbos for example), great for those of us making street fighters, cafes or choppers.

 

exCUSE me?!?!

YOU asked....

WE answered YOUR questions....

YOU Don't like the answers WE GAVE. NOBODY Is hatin' on it, NOBODY said it's crappy. YOU'RE the one that said those things. YOU didn't get the answers you were hoping for. WE'RE NOT sorry for the answers we gave.

If you want it to run better, we told you how. if you want it to be safer, we told you how. End of story.

NOW here's smartass:

YUP, we go again......another Newbie with a chop is gonna ask some questions. I bet he won't like our answers, and is gonna get bent out of shape. So----save the hassle, It's your bike, do whatever the heck you want with it. It if works, great. If not, so what. You can try something else. If it works, great. if not, so what. Rewind/play again. When you get tired and frustrated, then come back and ask. But before asking anything, read the INFORMATION OVERLOAD HOUR. It's mandatory reading for any Newbie, and we don't answer questions til that prerequisite has been met.
The next mandatory reading is on Valve Shim Clearance Procedure
Third required reading is on Brake Delamination
Last required reading is on VIN Decoding

Hope you have fun on your short rides.......I'm sure you'll turn some heads (though I'm not quite sure WHICH WAY they will turn).

There's only one tiny difference between wrenching and wrenching.

Ok, I'm done .........I feel better now--carry on.

Keep the greasy side down, and be safe.

 

Duplicate post removed

 

Still waiting on the pics of the full back bone, and neck welds.
Or are you trying to hide what I already highly suspect??

~Ghost

 

I'll take umbrage with that. I'm looking at his frame with the eyes of a (former) technician who is in regular contact with a certified structural engineer. The isue isn't the chop, it's the lack of strength in the work that has been done. Despite my proclivity to keep the XJ series of motorcycles stock, I have modified motorcycles before and am not against doing so; I'm just saddened with the number of people that keep turning decent motorcycles into dangerous peices of crap. This hobby isn't as easy as those damed TV shows make it look, particularly when you start messing with engineered structural assemblies. Mess up a frame and people get hurt, which is the exact opposite of what motorcycling should be.

Anyone showing their work or asking for advice should expect to also recieve criticism, not just reinforcement, otherwise there's no point in asking for advice or even starting a conversation in the first place.

 

Ummmm---- questions were asked and answered.

FIRST was a question about jets, pods, air boxes, carbs, etc........ Answered

SECOND was a question on plan/design suggestions.......Answered--(and argued about the answers, while at the same time stating

and, it just dawned on me....

So you're gonna just go ahead and trust your life to some PO'S work which has raised a lot of concern?

Then don't be.....pay attention to the suggestions for strengthening your ride so you can live long enough to enjoy it

 

I''m just going to put it straight here.

There is an obvious mod done to this bike based on information that I offered years ago. Namely the XJ700 front forks.
In the pictures provided. I am not seeing the triangulation bracing of the back bone. This leads me to believe that the back bone has been modified.

If the back bone has been modified as I suspect. It leaves the joint at the neck extremely weak. The added leverage of the longer XJ700 fork will act like a cheater bar and twist the neck with the very real risk of unpredictable handling, loss of control, and very possibly serious injury or death.

The bigger engine clearly shows that the plan is to make the bike go faster. No reason for the engine swap otherwise!
This only magnifies the problem further. How can you control a bike at any speed if the front end is not tracking properly?

I have made nothing more than a passing mention of the high school hack job done to the rear. There are some issues that need to be looked at there also.

As the bike sits I would refuse to allow it on any run as it poses to high of a risk for causing an accident. Injuring or killing either the rider or someone else in the group.

The unknown fact is that I have been running in, and around the OP's state for years. I know the hills with the twists and turns of the highways as well as the back roads. I know what stresses the bike is going to be put through.

They are so proud of the state moto it is time for one of them to live up to it and SHOW ME!!
Show me that frame is safe.

Not hating on anyone. Just an experienced fool trying to help someone I don't know possibly stay alive!!

~Ghost

 

your answer to every question hog fiddles was to read the information hour that's why I called you a smart ass don't gotta get all butt hurt over it all yeah and I bet you do feel better ..
Sorry for not meeting your prerequisite to ask a question?
Thought you might know off the top of your head..?
I simply said there was no twisting when i rode it?
And plan on a rebuild ?oh and the jet size i need is 107.5...in case you wanna tell anyone....
I cant wait to read the information hour so you will talk to me more
.....sounds super......lol

 

That's cuz all the rejecting info is right there, and you can print it off. Plus there is a wealth of other info.

Totally up to you.

Ghost....just wondering---- what if it IS A 700 that had a 650 put into it ..... For whatever reasons the PO may have had....all stuff seems to point to originally 700

 

Thats all whats on my phone that you can see anything...
Take more later if you really want to see.

 

I would really like to put shocks back on it
Personally i think they look cool
Not to mention the ride

 

Ok, just saw the pics.... The tank mounts don't like 700 mounts

 

Ya ain't gonna do that without a lot of : cutting off what someone else put on and putting back on what they originally cut off. If you really want to see what originally there, I'll take a pic of both a 650 frame and a 700 frame

 

I have two other full frames.unmodified
Thanks though

 

Did you see the pics the neck is not modified still stock
Hey would you take a look at my thoughts on putting the shocks back on...without modifying anything on the existing frame too much... i have an idea on paper
Wondering what you think
Of course im considering the shock load and travel the bike would be raised back up 2 or 3 inches

 

Right now, the only place you CAN put the shock would be there------as long as the swing arm hasn't been welded in place. Cut out the straight links and unbolt the swing arm and you might have a place to start since the lower shock mounts are still there---

 

We can see your pics, but what we are most concerned about is the gussets/etc..... HERE: can you show us a clear pic of this area?

 

I dont but i will..at work now..
I can tell you they are absolutely still stock and strong...factory..
And no the swingarm is not welded...and thanks for your input...ill put some good pics up later ....i really do appreciate
Your help ...oh and the original shock mounts are still on the swingarm

 

Exactly what I was concerned about! Thank you!
The bracing is still intact so any twisting will be minimal. You can still look at adding bracing to the down tubes. A simple cross bar below the head pipes will help significantly. Some gusseting between the big center tube, and the smaller outer tubes would not hurt either.

The placement of the shocks on your drawing would be on to much of an angle to be any good. The swing arm end of the shock would have more up/down travel than the compression travel of the shock. The only option for shock placement would be an under-slung arrangement (soft tail). This would create more problems than it would solve. You would be left with the weight of the rear wheel and final drive hanging off the end of the swingarm unsupported. NOT GOOD!!

The best approach on that frame would be the springer seat.
You will still have the bucking rear, But the seat will isolate most of the impact and not throw you around as much. You will need to improve the bracing in the seat area. Some 1/8" flat plate where the frame narrows down to meet the back bone would give a solid front pivot mount. Completely fill in the area from the thin front strip up to the big center tube in the back bone. This will help reduce the flex in this area. Change that thin strip of metal in the rear to angle so that the bracing is both front to rear as well as up and down. This will support the rear spring mount of the seat.

The next place of concern will be the swing arm. The pivots are old and probably worn. The fixed mount is going to aggravate this further. Look into adding an X brace between the frame tubes from the pivots up to the seat. It would not hurt to change the pivot bolts to a through bolt.

Moving back to the wheel end of the swingarm. On the right side that poor helpless tiny bolt is going to get hammered on without mercy. Either the bolt will break, or the thin mount will tear away from the arm. This area really needs good heavy 0.25" plate brackets welded solidly to the arm if you want to keep the swingarm removable. Otherwise weld that point solid with some heavy gusseting. On the Left side it is attached to the final drive housing. This is nothing more than weak cast alloy and will eventually break from the stress. There needs to be some bracing from the strut tube to the final drive mounting plate on the swingarm to isolate the final drive, and transfer the impact into the frame/swingarm.

Now go back through the frame and look at every point where the tubes are welded together. Each one is a flex point. Gusseting as many of these as possible will significant help minimize any flex in the frame.

Once you understand what I have described. You will understand the meaning of poorly done. Everyone thinks it is so great to hack off the back of the frame without giving a single thought to restoring, and/or improving the structure of the frame to support the modification. That is what makes the difference between a good bobber and an ordinary hack job.

I have seen some very well thought out, and executed builds and would gladly ride with them anytime.
Do a poor job and put me in danger because of your carelessness. Guess What!

I will address the fuel tank later!

~Ghost

 

It makes no difference if it is a 700, or a 250 frame. The same rules apply!
Would you anchor the Millennial Tower with 1/2" hardware? Certainly Not!!

The structure must support the stress imposed on it.

~Ghost

 

And then some. Safety factor matters in all cases.

Sometime I might retell the adventures of a guy on a scooter forum who thought it'd be a good idea to build a racing frame out of conduit.


bruthaswade, it's not your fault that the frame is the way it is. That PO guy messes every motorcycle up (should have seen mine; so many little bodges that were inexpensive to fix correctly). We're just trying help you make sure it's safe and reliable.

 

No, that's not what I meant------ I was just looking quick, thinking "what if someone had gone backward, engine size-wise, and it wasn't a 650 frame with 700 front added on...and its actually a 700 frame to begin with." Then I saw some other things later to say "yup, 650 frame".

I wasn't looking at alternate structure at all..... I know full well what you were talking about----

 

The welds are nice..... in places
You ever seen those stock welds?
Ooof..?

 

Stock parts bike factory welds ....
Was surprising to me.

 

Now your starting to understand!
That is why the stock frame really needs some attention. Once you start modifying the frame. Those welds get stressed even more.

~Ghost

 

I'm not really sure why alot of the guys on here hate when you customize your Xj ? Its still an Xj we are just putting our own signature on our bike . It would be a pretty boring world if everyones rides looked the same . I love to see what guys do with there Xj's , i don't hate on someone for trying to be different .

 

Safety: Far, far too many "customizers" that come here have never worked on motorcycles before, let alone modified anything. Some (like the OP here) are working with something that was already modified and has suspect work.

Reliability: everyone wants to rush and get the look right before making sure the thing will run and ride. Many modify the frame with out concern for the need to have an airbox if using the stock carbs.

Rideability: many. many of those who want a "hardtail bobber" have never ridden a hardtail, and end up being suprised to find that they are not particularly comfortable if you happen to want to ride for more than a few minutes at a time (a sprung seat helps, but it's still not an all-day bike). This is why I reccomend making struts before making permanant frame modifications.

Collectability: most XJ's are common enough that major changes arent going to hurt the value, but there are a few models that are both rare, and desirable.

Very few of us have entirely stock bikes, and those that do typically have multiple bikes.
I would live to see more people making their motorcycles look different. Unfortunately 3/4 of what people are building now is a slightly different riff on the modern "interpertation" of a bobber. Same, same, boring; not different anymore.