Just bought an XJ still wont start

Hey guys I'm new to the thread and i'm lookin for help. I just bought an XJ750 Maxim for quite a steal ($125). The previous owner stated that he thought he filled it with too much oil and the bike didnt start.

So i take the bike home, and here is a list of what i have done.

-charged battery. battery took the charge well
-i replaced the fuses

-bike starts right up.

So now im happy, got a bike for so cheap. So i decide to fill the tires with air and test ride around the local block. Bike rides ok minus needing new spark plugs.

now is where the problem starts. I replace the spark plugs per specs, and i add about 3qts of 20w-50 oil....and im thinking this is where i went wrong, long story short the bike wont turn over now. after i release the starter i hear the exhaust backfire a lil bit followed by some air being sucked somewhere. i really think some oil maybe leaking where it shouldnt. also after a few more times of trying to start it, I think its draining the battery, the starter motor spins slowly each time and eventually wont turn until after i charge it again..I have VERY little bike tech knowledge, if someone can guide me on to where the problem is it would be most helpful, and if i havent been clear on explaining the problem please feel free to ask.

 

Well for starters, you shouldn't be trying to ride a $125 motorcycle until you've at least CHECKED a LOT of things, starting with the rear brake shoes: http://xjbikes.com/Forums/viewtopic/t=15874.html READ THIS.

But YES, you've overfilled it. If it had any oil in it at all and you added 3 qts, it is now overfilled, and has probably pumped the air filter full of oil (via the breather.)

The bike takes a TOTAL of just under 3 quarts FROM EMPTY, with a new oil filter. There is a small number, probably "2500CM3" cast into the clutch cover near the filler. This is your oil capacity in CC's. A slight overfill is OK, to keep the low oil sensor happy during hard acceleration.

You can get the FRAM CH6003 filter almost anywhere, and it comes with both necessary o-rings.

You need to use MOTORCYCLE-specific oil, not car oil. 20w50 is fine as long as it's motorcycle oil.

Checking the oil level is done with the bike on the centerstand or held level, and fter the engine has been off for at least ten minutes. There is a "sight glass" on the clutch cover; the oil should be above the upper marks, but with a bubble showing at the top.

DO NOT RIDE THE MOTORCYCLE UNTIL YOU HAVE INSPECTED THE REAR BRAKE SHOES AND LIKEWISE CHECKED THE FRONT BRAKE FLUID.

 

Howdy, I too am an owner of an 82 Maxim 750, I got mine from a guy who left it outside in Minnesota for ten years, since the battery was long gone I couldn't start it. I recognized it for it's potential, so now I am starting a detailed restoration. I encourage you to take a mirror and check all those hidden parts, I found a crack in my frame, turns out that water had gotten inside the frame and it froze, splitting the frame tube just underneath the shifter, if I had not been the curious type I may have ridden it without knowing my frame was bad. I bought mine for $400 and plan to invest another $2000, maybe even more. You said you replaced fuses, did you find out why they were blown? Anyway, be careful and heed the warnings.

 

Now that you have a Bike to ride; you really should pretend its an Aircraft.

Before you take flight; YOU should thoroughly inspect the whole machine and check-off every item needing scheduled maintenance before issuing a "Air-worthy Certificate".

Treat yourself to a GENUINE YAMAHA Factory Workshop Manual for all the money you saved buying the Bike.
The "Factory Book" will become your new best friend.

The Factory Book is two books in one.
The Owners Manual.
Workshop Manual and Procedures.

For what you have to and what you are going to need to do, to bring your Bike up-to-snuff; acquiring a Factory Book to guide you through becoming familiar with the Bike and having a reference manual for fixing it up should be what you'd like from Santa.

Provided you've been a good boy.

 

thanks fitz, i did check the basics that you mentioned before buying it. I actually did get the bike running this afternoon. a neighboor of mine is in a bike club and he noticed that my bike was running rich (i guess he smelled gas after trying to start it) So what he did to get it it running is that he hooked up jumper cables to his car, attached the other positive end to the bike battery, grounded the negative to the frame, and pushed start....it fired right up, he then left off about 80% of the choke. Told me the battery wasnt turning my crank well enough to start it. He said that i was getting too much fuel, not enough spark. Could the oil have flooded it?

 

Welcome to the forum and the XJ communitiy.

Knowledge, patience and diligence will give you the freedom you seek from the dodgy mechanics wanting to rob you but you still have a price to pay.

Your journey starts here and ends with a reliable maintainable bike you will be very proud of or with a bucket of wasted cash, an annoyed spouse and a frustrated owner of a "cheap" bike. There are no shortcuts so don't bother looking for them. You might get it running today but you have a bike that's nearly 30 years old with seals, electrics etc. designed for a service life of fifteen years at most and something else will need attention very soon. You can find that problem now and fix it or wait for it to find you one sunny afternoon several hundred miles from your home.

My advice is to start reading the manual and gently tinkering with no particular purpose other than to familiarise yourself with the bike. Don't expect to ride it for at least a few months during this phase. When you find something you don't understand .. come back for assistance.

Drain the oil, replace the air and oil filter, refill with the correct quantity and grade, clean the spark plugs and try to start it if you must ... then come back and start from the beginning.

Valves in spec
Compression test
Fuel system, carbs, tank, petcock, etc.
Electrical, ignition, starter, charging circuit, lights, etc.
and before you "hit" the road ...
Brakes

You'll know a thing or two about motorcycle maintenance by then

 

First Welcome to XJBikes!

XJ's require maximum juice from the battery to start. Most of the voltage goes to the starter motor, not enough left over and your coils won't fire. Be careful using a car to jump your bike-too much amperage could fry your electronics and they are expensive to replace.

+1 to all the advice you have been given in the previous posts.

No oil won't flood (as in too much fuel) your engine, but it could get into your airbox via the crankcase gas recirculation tube (breather) and soak your filter and get in your carbs. If your air filter is clogged with oil then not enough air will enter your CV carbs and the air-fuel mixture will be too rich.

You must get a manual and begin at the beginning. There are also several great books out there that will give you the 101 of owning, riding, and wrenching on a motorcycle. No offense but your safety, sanity, and pocketbook will all depend on getting both sources to "get" you there.

I have been riding motorcycles since I was 4, and have owned one since I was 14. That's when I began working on them and now after almost two decades of doing my own maintenance I still learn new things all the time. This site is by far the best source for learning about your bike and will be as good as a college level course for teaching you, BUT you must supplement with the above sources and bring yourself up to speed.

So settle in - get your books and start with making your bike safe and your fun last!

 

Begin with a Compression Check.

It's like being a Doctor and giving a patient a Blood Pressure Exam.
That let's the Doctor know if it's OK for you to go home an play tennis or take it easy until a donor heart can be located.

 

"If you're going to repair a motorcycle, an adequate supply of gumption is the first and most important tool. If you haven't got that you might as well gather up all the other tools and put them away, because they won't do you any good.

Gumption is the psychic gasoline that keeps the whole thing going. If you haven't got it there's no way the motorcycle can possibly be fixed. But if HAVE got it and know how to keep it there's absolutely no way in this whole world that motorcycle can KEEP from getting fixed. It's bound to happen. Therefore the thing that must be monitored at all times and preserved before anything else is the gumption."

from Zen and the Art of Motorcycle Maintenance ... Robert M Pirsig pp303-304

 

thanks for all of your responses. i have to admit i feel a lil overwhelmed by them so let me back up and start from the beginning.

last nite i drained the oil. ALL of it. Put on a new filter w/ o-rings. I purchased a new battery and let it charge over night. This morning the battery shows a full charge. I hook it up to the frame and try to start it. The motor cranks alot better and doesnt die out...but alas it wont turn over. Before I begin to open my manual (which I do have one) i want to know why i was able to get the bike running AND riding before. When i first got the bike all it was that took it to start was reseating the fuses, the bike started right up and i was able to give it gas and go thru at least 3 gears. the only thing i did was put in oil and change the battery. Any insight?

 

As you can see this bike really isnt a piece of junk, but it wont run! lol

 

-The reason it was recommended that you get a compression test is so that we'll know if you're dealing with a major or minor issue.

-You could be having a problem with the wiring, fusebox, safety circuit/wiring, CARBS, a TIGHT VALVE or two, etc.

-You could also have polluted the air filter if the bike got overfilled with oil; that will keep it from starting, big time.

Nobody said the the bike is a "piece of junk" but like most 30 year old bikes, it's going to take a little --ok, a lot-- of work to make it run reliably and stop safely.

If you want to do it right, start in the "maintenance" section of your manual and go throught the entire thing, leaving nothing out and taking no shortcuts. Do it all, and in order, and you'll be off to a good start.

 

82XJ,
What the guys are trying to tell you in their own special way is we've seen a hundred guys join up having just bought a bike and upset because they can't ride it RIGHT NOW. No one is giving you a hard time even though it might sound like it, they really don't mean it that way.

Anyway, we see so many guys join up then give up 2 weeks later and disappear simply because they weren't willing to give their bike the time it really needs to A. be safe to ride (rear brake) and B. be reliable to ride (checking it from the front wheel bearings to the rear).

We don't want YOU to be in that group....the guys here are talented and actually pretty nice to one another, or I never would have joined myself.

Take a few days to get to know your bike, if you need a manual, pm me and I'll hook you up via email. You've got a really nice bike for the little you paid for it....take the time to make it reliable enough to ride it without fear of it breaking down or locking the rear wheel.....that's all the guys mean to tell you. As long as you've got half a brain, it's a piece of cake to do and won't cost you much either. Most guys can get their bikes safe for a lousy 200 bucks if they do their own work. Remember, we ride on only 2 wheels....tires mean life or death unlike a car which only gets a flat.

And...Welcome to the club!!

jeff

 

Thanks fitz and jeff

I realize that I have alot to learn and dont worry im not taking any offense to the posts. one thing is for certain tho jeff, i wont be like "so many guys join up then give up 2 weeks later and disappear simply because they weren't willing to give their bike the time it really needs" I just got her up and running strong after re seating the spark plugs. But i know that this isnt over for her.

My ultimate goal is to cafe this bike. but first i want to (as fitz put it) start in the maintenance section and give it a clean overhaul. i come from a line of all fuel injected bikes so going back to where it all began with these carbs will be my next step

 

Your next step needs to be a check and adjust of the valve clearances followed by a compression test; so you won't waste a whole bunch of time/money on a mill with a "problem cylinder." We've seen this happen time and again here; members spending umpteen thousands of hours and hundreds of dollars on carbs and cosmetics only to discover one cylinder won't make compression for squat.

Begin at the beginning; if the "air pump" (which is what an internal combustion engine IS) isn't healthy then everything else is just spinning your wheels.

And a compression test is how we find out. AFTER the valves are in spec, so you don't panic unnecessarily.

 

Hi 82, you said something quite confusing, " the motor cranks alot better and doesn't die out... but alas it won't turn over." Can you explain what you mean? If the starter turns but the engine doesn't, then you have a starter clutch problem. After looking at your past writings, it sounds like you may need to check the brushes in your starter.

 

Just to pile on.

When I bought my xj it ran-just not very well.

I found this site and read. Did not post many questions-just
searched and read.

After following ALL the advice, steps, procedures, With No Short Cuts!
My bike ran like she was new. And still does thanks to the site.

And don't forget- Len, our supporting vendor has any/all the parts
you'll need to get her up and running. Fair pricing, fast del, correct parts.

good luck.
ron

 

I respectfully disagree with BigFitz.
Here's why I think (and was taught, drilled and almost fired once) that
the Compression Test should be done first.

The results of the Compression Test determine if you should bother Adjusting Valves, or doing anything else at all, ... before learning about way below specifications Compression, ... or, none at all.

The Compression Test will indicate if the Condition of the Engine is worthy of Adjustments and Tuning, or IF there are issues totally unrelated to Valves that will require servicing before removing the Cam Cover and Adjusting the Valves.

The INITIAL Compression Test will reveal quite a lot.
IF there are TEST Results showing any severely LOW conditions, ... a follow-up WET Test will decide if the Condition is:
a) Rings
b) Valves

If the problem is Rings. You have work to do before adjusting valves.

If the problem is Valves. Cross your fingers and pray that a Valve Adjustment is all that is needed to rectify the problem.

It is not a good practice to Adjust the Valves; first.
You may be wasting your time if the Hole(s) has some problem that isn't Valve Related.

 

What's to disagree with?

A compression test IS the "first step" but since he already owns the bike, getting the valves in spec first will simply save the potential grief of a tight valve throwing off the numbers.

Even the factory books say that the valves should be in spec BEFORE doing the compression test.

In my factory 650 book, "Maintenance" Section INDEX:

ENGINE
A. Valve Clearance Adjustment...............(page) 11

Then AFTER B, C, D, E, F comes:

G. Compression Pressure Measurement...............(page) 18.

You're not disagreeing with me. You're disagreeing with the factory service manual.

I don't. Valves first, there's a reason for that. And the reason is a couple of tight valves, especially on the same cylinder, can really throw off your readings.

If you don't believe me, look in the manual.

 

I just pulled my cam cover tonight, everything looks sweet inside, tomorrow I will check my valves. Does anybody know if there is supposed to be any looseness in the cam chain? or is the tensioner supposed to keep the chain tight?

 

what i meant steve was that before i bought the battery and when i tried to start it, the motor would crank and wouldnt start, i would keep on trying to see it the bike would turn over, but the longer i held the starter the motor would "crank" or try to start the bike slower and slower. then it would get to a point when the starter motor wouldnt start

 

when your trying to start it don't give it any throttle at all. try half choke for a 5 count then go to full choke for another 5 count. giving it throttle defeats the choke and will never go. a car battery jump won't hurt anything and it will save your new battery from running down.
first thing to do is, on the fuel valve you'll find 2 hoses, a big one that has gas in it and a small one in behind it that is a vacuum line to turn the gas on/off. these valves are known to leak, filling up the carbs then the cylinders or your garage floor.
pull off the larger fuel line and make sure no gas seeps out of the valve

 

I must disagree. If you jump a bike battery with a car battery bad things can happen. If you reverse polarities you blow up your bike battery and sulfuric acid runs all over your bike and possibly you. If you start the car it's much higher charging amperage could damage your bike battery and your bikes charging system.

Now if you meant only hooking up the car battery with the car off and making sure polarities are correct and attach the negative clamp to the frame and not the neg terminal of the bike battery...then ok it's safe.

My point about being careful related to these possibilities and it's worth noting that a decent battery charger will keep your new battery from running down and is much safer. Also if you need to hold your starter on so long it's draining your battery, then you're wasting your time and the life of your starter. Plus the longer you keep turning over with no fire the farther you're getting from it firing anyway. If it doesn't start after about 10-15 revolutions stop and fix what's wrong (compression, spark, fuel, air) and away you go!

+1 to everything else you said Polock, I agree. And you have problems with your carbs floats if your petcock is flooding your crankcase.

 

So here is where I am. Bike starts now and runs with a new battery with no problems. A friend and I are working on the carbs n cleaning and getting the bike as safe as possible. So far I can ride the bike and go thru the gears with out any weird noises or problems gear shifting. The brakes work well. Turning doesnt give me any problems. My only concern mechanically is that the bike does run a tad rich. Hench the carb and fuel work.

After I finish going thru my checklist I want to cafe it. My question is this. I see clubman bars on most cafe conversions on xj's and xv's. I was wondering will the fork on my 82xj 750 take clubmans with lil or no modification? Or can I order clipons for the forks?

 

How do you know it's running rich, are you checking the plugs, or is it smoking ?

 

when you take off all that stuff holding your bars on there now your going to have a few holes in the top triple clamp that will accept risers from all kinds of bikes and atv's , that gives a place to bolt on bars but you have to watch they don't hit the tank.
clip-ons on these turn out to be really low unless you spend big bucks for helibars or some adjustable ones, but it's been done.
Mercuryman, if you reverse polarity, that's not jumping it, i'm not sure what that is but it's bad

 

No smoke. Just that the plugs arent staying fully dry and I can sometimes. Just sometimes get a faint smell of gas

 

Carefully screw in the pilot mixture screws & take note of how many turns it takes to get to a soft bottom, don't force anything, report findings to HQ.

 

"Working well" doesn't mean safe and reliable. You can't tell if the rear shoes are delaminating unless you PULL THE WHEEL AND LOOK. This is an extremely common issue with these bikes, and can wreck you. Serious business; READ THIS: http://xjbikes.com/Forums/viewtopic/t=15874.html

As can a popped front brake hose; check the dates embossed in the front brake lines. They were supposed to last 4 years; how old are yours?

You also won't be able to truly fine-tune your carbs until you're sure the valve clearances are in spec.

Again, from the factory book:

 

Thanks for the insight. I've never wrecked before and I definitely don't want to start making it a habit.

 

Anyway I want to put on these clubmans....anyone have any experience putting on these yourselves? Where can I get the parts? Again I'm looking for a cafe/sport look so after changing the bars what other mods have been done to get that look, like rear set position or the height of the back end

 

I know it says that in the Book.
"Maintenance".

But, the work you have to do when you acquire a $125.00 Used Bike does not come under the Term: "Maintnenance".
Not at all.

The work you need to do is: "Diagnostic"

We aren't dealing with a bike that we know was Factory fresh when the Salesman handed-over the keys, ... and was rigorously cared for according to the Maintenance Schedule.

Therefore, the thing to do, ... is: Diagnose.
BEFORE tuning.
Before anything.
Because if the Cylinders are scored or a Piston is holed, ... or the Ring are bad ... or there is Rusted components from sitting around ...

The Compression Test reveals those faults BEFORE the Cover is removed and Maintenance is initiated.

IF there was a section in the book covering what to do when you resurrect a sleeper after the bike sat for any length of time. ...

Adjusting the Valves would not be anywhere near the top of the list.

You might find Valves after a long list of Safety Related and Diagnostic Tests and Inspections.

Compression
Delamination of Brakes
Fuse Panel
Frame Damage

 

Get the bike running correctly before you worry about "mods."

 

Thank you fitz and you make a valid point about getting the bike running correctly. Like I said in my previous post my friend and I are working on that. But my question in my previous post still stands. I like to plan ahead and get ideas.... if that's alright....

 

Polock, my point was that in trying to jump from a car battery someone could reverse polarity and as you say that would be bad.

82XJMaxim, do a search for clubman's or bars on the net. You will find a variety of examples. You can then compare your mounting clamps and the bars you find that you like and see if they are compatible. You will also want to check the geometry of the new bars to see where they will be as you go from left to right lock to make sure they will fit.

Measure your stock bars width, rise, and pullback. Then compare the new ones based on the differences. This is a modification that is done all the time, isn't hard, but requires planning before you drop your change. One thing to consider is your stock cables, major changes in your bars may require new cables, or rerouting them.

 

what about the master cylinder?

 

Got it thanks mercury is there any one that has any experience in getting clubman bars? Anything I should know? Would I have to change anything with the pegs?

 

OK, you asked.

Clubman bars are a way of re-creating the riding position of clip-ons (or close to it) by still using the original mounting points. IF your bike has conventional 7/8" handlebars, it's a piece of cake.

Your username suggests that your bike may very well be the series of Maxim that has adjustable cast "modular" handlebars. If that is the case, the swap to clubmans (or any other tubular bar) will require a bit more modification; you may even need to swap out the upper triple tree.

When going to lower bars, even just a more conservative "Euro" low bar (my fav) you need to consider the brake master cylinder (mounting angle and compatibility with the new bar) as well as the length of the clutch cable and upper brake hose. The smaller cables can generally be re-routed, but if you want the mod to be PROPER you'll need a shorter clutch cable and upper brake hose. (No biggie, many of us have done it.)

The other thing you need to understand is that the Maxim was designed to be a "cruiser" styled bike; transforming it into a high-tailed Cafe Racer will require a whole lot more work than it would had you started with a Seca. You're talking about jamming a square peg in a round hole; yes, it can be done but it won't be quick nor easy.

As far as the pegs: If you do manage to get clubmans fitted, you will likely find the riding position cramped until you change the location of the pegs; however:

You're not going to find rearsets anywhere made to fit your bike; that would be a DIY engineering feat. You cannot "jack up" the rear end too much, you'll compromise the driveshaft because it wasn't designed to operate at an extreme angle.

My recommendations are to get to know the bike before you make radical changes to the riding position. Handlebars are the first thing I've changed on every Jap bike I've ever owned. Clubmans may look cool, but you may go to a whole heck of a lot of trouble only to make yourself damn uncomfortable. Look in my gallery; that black '83 is an "all day without a sore butt" bike. Bars aren't stock, but not radical either. (Seat only looks stock.)

All I'm saying is think about what you're doing before you do it; and remember everything that LOOKS cool doesn't necessarily work quite that way in the real world.

Don't build a bike you can't enjoy just because it looks cool.

 

Hmm.. sage advice indeed my friend. Comfort does trump style in my book, it sucks to get a cramp while you ride.

I like the euro style bars myself. My XJ550 Maxim has non-stock bars that are 4 inches lower and put my palms down towards the ground, knuckles at very slight angle. The clutch cable is re-routed and works fine, but 2-3 inches shorter would be better. The MC was fine in it's new position, but the upper brake line is 4inches shorter. I took the bike to a custom line shop and had them fabricate on site. Everything else is stock and only had to be routed a little differently to make it all tight (as in right).

The position is perfect. I have maximum control with no fatigue. I can lay all the way down, sit back, or maintain normal posture, all very comfortably. And the lower profile of the bars looks much better (so style with comfort there).

+1 to bigfitz's advice. When modifying follow a rule similar to carpentry, plan twice (or more) spend once.