so these intake tubes suck! ( literally, and figuratively)

well i finally tracked down and installed an airbox on the 82 xj650. last weekend i made my own intake tubes from airbox to carbs from radiator hose. they seemed to work fine, at least for now.

i jsut received my new to me correct yamaha intake tubes in the mail yesterday, so today i took the other stuff on, and tried to install the new ones with no luck.

i could only get one to fit snugly, the others are somewhat touching at the top of the carbs, but have a big gap at the bottom. i made sure the little "nub" is at the top as it should, and tried a few different variations as far as where they went in relation to the carbs.

the only thing i can see that would be wrong, is my airbox "bends" inwards, so i am going to take it off and heat it up, push it back out, and cool it down so it will stay "flat" across the face.

am i missing something here? or should i just keep the radiator hoses in there as they seemed to work perfectly?

thanks for any info,
ken

 

When I put mine on, I noticed how tight the space is between airbox to carbs. What I did to get it right was put the clamp on where it is supposed to be on the boot, tightened it until i was able to pull on the clamp and it would pull on the entire boot onto the carb body. When you have it positioned where you want it, tighten it down and you should be good.

They are such a pain.

 

The stock intake "boots" are carb specific; as the carbs don't line up with the airbox anyway. the boots are canted the end carbs are wider than the the holes in the air box, and at a slight angle inboard and I think upward. Numbers 2&3 carbs arent canted as much but the horzontal angle is equally off center, either up or down, just like the end carbs. Theirs a rubber lip where they seat into the holes in the plastic of the airbox and most probably need to be seated in the air box then twisted untill the angle of the boots fit snugly over the air horns of the carb bodies. A little vasiline or (Len forgive me) wd40 may help.
If you take all 4 boots and line em up vertically on a bench , on the same ends, you should notice that they are slightly different. the 2 oddest ones are for the end carbs and the other two are for the inner carbs. It's 11pm and in the low 30s' outside so I won't go look but the angles of the inlets of all four boots should line up with the holes in the airbox even though the carbs are wider (and I think lower than the airbox)
I've had mine on and off at least 5 times (for other reasons) within the last year and they fit snug enough as to where I don't even use clamps anymore.
Radiator hoses may work fine on the carb end, I can't figure out how they can seat on the air box. The corregated ones, (with ripples) will definetely reduce top end air flow and add turbulance to the intake charge, if you like to go fast that is. Lol Padre

 

i leave the airbox loose. wd40 the inside the boots. get everything lined up and on as much as possible. push the air box as far forward as it can go. tighten down the bolts. and finish putting the boots on.

a little lube on the boots makes the job SO much easier. specially new boots. but also do like the above posts mention and make sure you got the right boots on the right carbs. the outer boots are a touch longer then the inners. the bottom portion of the boots are also longer then the top portion. the curve of the boot needs to be upwards.

putting the boots on should take no more then 5 minutes. once youi've got the hang of things.

 

Agreed. First couple of times I did this on a bike, I thought I was gonna loose my mind before getting it together. That was before noting the subtleties of the boot designs and the airbox mounting...

Anymore I get them all greased up with WD-40 and just shove them in between the box and the carb, and rotate them around until they find their proper fit. They will usually pop onto both ends real easy at this point.

My airbox has the concave shape described too, I guess this is a material aging thing...I like his thinking on how to reshape it. But it doesn't give me trouble getting the boots to go on both ends...