Bought it, crashed it, fixing it.

I bought my '82 xj750J maxim about 10 months ago, for $600, my friend has a "81 xj750 seca, so it was a cool match, however the bike had no turn signals, and a trailer light for a brake light, a dead battery, no air filter box or filters, had filter over the carb openings and ace bandaged them on. I knew nothing about bikes at that time, including how to ride, just a half decent machanic and thought it was a good deal for something fun to work on.

Bought what i had to, including pod filters, had it running for about a month, and i layed it down... actually i hit a curb... on the left... i live in america, dont ask how it happened. Actually do. the forks were replaced with 650 forks with the leading axle, but there was no spacer on the axle, and they didnt use the 650 brake rotor, but did use the caliber, which dont size up. rebuilt the forks, and bought all the proper parts to ride smooth, so I thought my only damage was the side engine cover, gas tank and some scraped up fins on my head... O' nay nay. My engine started leaking a touch of oil, had smoke coming out under header #2, stinky exhaust, and everytime i ran over 6000, my ankle would get covered in oil from the small pod filter on the trans breather.

I thought the simple expaination was a blown head gasket, cause smoke and oil to get out, and pressure to get in my crank case. so i bought a complete gasket set, and all the compression rubbers for the head and valve cover.

I took the headers off, and i can see #2 had a blow by on the gasket, i can see the carbon, so i started looking, the bottom of the stud on the side that hit the curb is up about 1mm, and the oil had pooled above the engine cover. I took one carb float bowl off, carb #4 (easiest to reach screws) having been extremely nervous about the carbs do to horror stories, I found my main jet floating around the bottom of the bowl, i put it back and it tightened in proper. Now i read about this rear oil plug, which i didnt drain, think there was too much oil, the window is really grimmy, so its hard to see in.

My question, now what?? i dont think its the head gasket because of the individual issue details. I'm gonna order the carb rebuild kit, or should i purchase the overhaul kit? the carbs arnt as scary as i thought (first multi-carb vehicle). Should i just try to retorque the studs to see if that stops the little oil leak? should i still fix the head gasket since i bought the parts? id like to save the parts in case i need them.

I was gonna do a complete head job, but don't wanna get in over my head, no pun intended. I wanna know if I can get away with a retorquing of studs, re-shimming the valves, replace the intake and exhaust gaskets, valve cover gasket, Go thru the carbs and possibly rebuild, though the one i looked in was pretty clean looking, just need a going thru. and completely drain my oil from both plugs, and filter, and making sure i put in the exact amount?

I know this is a bit scattered, but thats how this bike has my brian. These are just the mechanical issues.

I dont regret buying this maxim for a minute. They have identity issues, cruiser bike style, sport bike engine. but any answers for this from real xj guys would be much appreciated.

 

jkstull,

Welcome to the Club. It sounds like you really want to get that 750 running to form. Good News...you've come to the right spot. There are some members here who really know these bikes; I mean "REALLY" know them. I've only been a member for about 18 months, but man...let me tell you...I've taken, with the help of this Forum, a bike that would have ended up in a scrap yard to a fairly decent running steed. I get a slight "rush" everytime I turn the key and the bike starts. Order a Manual for your bike and get familiar with this Forum. I didn't ride my bike for 6 months learning and wrenching on it. What I've learned thus far is immeasurable. You're going to learn that bike front to back, top to bottom and if you like it now...just wait. I tell members new to bikes to strip the bike down and start to bring their bikes back to manufacturing standards so you will become familiar with your bike and know how she is "suppose" to run before you start messing with modifications like PODS. I don't try to help with mechanical issues I haven't dealt with before like PODS. I do read a lot of threads for information and general knowledge. There are other members who will chime in regarding the PODS but to my understanding there is a issue with the PODS taking in the "right" amount of air at each carb that the stock air box and constant velocity stacked boots were designed to do. IMO, there are a few other things you need to do (like checking your valve clearances and cleaning your carbs) to get to the point where you can use a formula to determine what jets you are running and what jets you might need including adding something to the PODS to more or less stack the air entering the carbs. Hope this helps.

Gary

 

Yea, I've already learned alot, and will learn more as I go. I've read the haynes manual from cover to cover about 3 times. Unfortunatley, it's not the best manual I've ever read.
I have 650 forks on the front end, single disc brakes, a seca 18in rear wheel, headers, xs1100 rear shocks and pod filters... going stock is out of the question.
I just want a reliable, fun bike with a bit of my own style in it.

jkstull

 

(quotes)
Now i read about this rear oil plug, which i didnt drain
* the 10 MM "Middle Gear" drainplug is to be ignored - do not touch !

My question, now what?? i dont think its the head gasket because of the individual issue details
* A compression test will tell you if you "ruined" the head gasket when you whacked the curb. You may want to try re-torquing the head bolts and heat-cycling the motor before ripping it all apart.

I'm gonna order the carb rebuild kit, or should i purchase the overhaul kit?
* You can clean the carbs fairly well without breaking the rack, and if you don't ruin any gaskets you only need 4 little PILOT "O" rings.

To clean your oil window, you need to remove the cover and you'll need the gasket.

Read the carb cleaning threads, check your valve lash, brake and tire date warnings, and maybe route your crankcase vent into a catch bottle for now.

 

Thank you for the info on the carbs, and the heads. and ill be sure not to mess with the middle gear.
what should the torque settings on the studs into the crank house be? i looked through my book real quick and couldn't find it. i wanna make sure the studs are all the way down.

As far as tires and brakes go, I've replaced all that within the past 12 months, and I'm assuming valve lash is the same as valve clearance. and the catch bottle is a good idea, i might use a flask or something to make it look nice, cause I'm sticking with the pod style filters.

Whats heat-cycling? and would you guys recommend me purchasing a 2 or 4 dial vacuum gauge for synching myy carbs? you only do 2 at a time, so do i need four?
Also, is a color tune really with the price?

NEW SUBJECT. my headers look nasty, and my exhaust, i finally got all the black paint off the chrome, and some of the chrome is gone, explain why the PO painted it. So I was considering powder coating, or ceramic coating, which is better for exhaust heat and durability?

 

Just in case, here's a picture of the way a catch bottle can look:

 

Thanks alot for the info, the picture really confirmed what i was thinking. Does anyone know anything as far as power coating an exhaust system?

 

"Jet-Hot" coating is the high-temp version of powder coating; there are all sorts of cool finishes available.

 

I just used barbecue high temp paint (flat black) it's worked great so far.

 

There is a 'Jet-Hot' "color" that is indistinguishable from polished stainless.

It depends on the degree of investment you're making in the project.

 

Thank, i looked into the jet hot, and maybe on a future project, im just gonna keep everything before the rear set black, and have a good chunk of the muffler left chrome. itll work and almost look like a heat sheild.
Thanks for the advice.
Now here is a xj riding question. I found it unusually hard to find neutral while riding last season. Seemed i only found it when trying to shift to second half mindedly, is that normal on these old beasts? is it something clutch wise? or maybe because my carbs were outta whack? carbs seem to be the root to all problems on these.

 

You need header paint for the exhaust. The paint that you used will burn off on the pipes up close to the motor.

 

It's only "normal" in that it's a common symptom of a dragging clutch.

Start with the lever, the cable, and finally the adjustment. The clutch isn't fully releasing when you pull the lever.

 

Ok, i looked into it a bit, and the only thing i found that stood out is the peice around the tip of the wire, that goes inside the handle, sort of a metal sleeve for the end to rotate in, that was really worn down. Ill prolly just replace the cable, just for reliability sake.

Next, i have a stock airbox, but missing the rubbers that go from the air box to the carbs, not even sure what to call them. I'm considering putting it on my bike, i know the carbs have to come off, but does anything else have to come off to put the airbox in?

 

STUPID QUESTION: when i replaced my front tire, the guy at the shop said the rim requires a tube, is this true? and does the rear rim require one? the tire i had put on was a tube/tubless, and the rear i plan to math to that one. thanks

 

Howdy JK, if you have the stock alloy wheel then you do not need a tube for your tire. And if this is the case, run away from that tire guy as fast as you can, 'cause he's either an idiot or a con man.

 

well im starting to feel he maybe a bit into the easy way, though I know he's more a dirt bike guy, the only thing I count on him for is balancing tires, and getting that tire to seat when i couldnt. thanks.