Maxim 750 wont start suddenly

To start off, i'm new to motorcycles. I like them a lot, but i only know minimal repair knowledge. like, replacing spark plugs and stuff. I just bought a used Yamaha Maxim xj750 and it was running very nice. When i bought the bike about two months ago almost, it had a dirty carburetor, and and front piece with blinkers, a headlight, and a radio. I took the front piece off and put a headlight from ebay on there, no front blinkers, and i also replaced the megaphone muffler with a waaaay quieter muffler which seemed to add good back pressure to make it run smoother. that or it was my imagination, again, im new to this.

The guy i bought it from swore up and down that he had done a full oil change with 10w40 motorcycle oil. Stupidly enough, i believed him. I was riding the motorcycle and had switched into third gear and began to accelerate. then it started making a louder high pitched noise while coming to a squealing halt. I held in the clutch and then it started to roll to a stop and then it shut off. Won't start now. I checked oil, put more oil in because it was incredibly low, check the spark plugs which all worked seemingly fine. I did have to replace one fuse to make the odometer and speedometer work. When i try to start the motorcycle it makes a fast high pitched noise like it almost wants to start but wont. If i try to much, i have to recharge the battery. I dont know whats wrong and i was hoping to maybe find a solution i could do myself without spending a fortune to fix the bike.

 

what year is it

did your oil light come on? sometimes when the oil light comes on if you have a defective diode block the starter will spin

if it is an 82 you do not have a diode block

 

Did you check the oil level prior to riding?
Is there any visible signs of an oil leak?

 

Its a 1982 maxim 750. and i dont see any signs of an oil leak. the only odd smell i'm pretty sure is the carburetor seeing as one of them is very dirty. i just havent gotten around to cleaning it yet.

 

I think you need this:
http://www.xjbikes.com/forums/threads/the-information-overload-hour.27544/
And this:
http://xjbikes.com/forums/threads/in-the-church-of-clean.14692/

It IS a lot to digest, but truly required for a fundamental snapshot of what path you are about to take.
Ask questions as required, there are very helpful people here.

So, no leaks but did you check the level before you rode?
"... put more oil in it because it was incredibly low..."
That is disconcerting.

 

i didnt check before i rode the bike, but when i checked the small window, it was like a puddle just sitting at the bottom

 

While on the center stand or side stand?

 

side stand

 

i don't know why it stopped but

the starter spins fast and could make a noise like that, listen to that.

don't run down the battery down that low, it don't like that. 3 or 4 five second tries should tell you if it's going to go or not.
keep a battery tender on it while you're investigating

 

oil needs to be checked on centerstand and/or put a level across the frame to level it and look at oil it takes a few min to fill the sightglass

 

thankyou everyone for trying to help but i took the bike to a mechanic and within two minutes of hearing the bike try to start diagnosed it with a bad motor. Im gonna go cry myself to sleep for the next week. If anyone has any suggestions to a new bike thats below $1000 then that would be great, but im just gonna go sell this one for parts.... R.I.P

 

http://www.ebay.com/itm/COMPLETE-EN...ash=item41c5295112:g:wZ4AAOSwa-dWs4~v&vxp=mtr

 

i can look into it, my friends were saying the same thing, they want to help me try and figure it out. i can think about it. thanks for the link

 

I have never had to tear a whole engine down for 'having a bad motor', and would be inclined to take the mechanics diagnosis with a grain of salt. You are new to motorcycles and you need to become better versed at becoming your own XJ mechanic. Where in the states are you? There may be another member who could stop by and give it a listen in your area. Or at least see if there is any opportunities for a second opinion.

Here's the thing with motorcycle mechanics, some actually know a thing or two, some go to the Tech school and learn very rote subjects/ troubleshooting skills often times for very specific newer bikes, some mechanics are younger than your bike. My personal experience is that I found out really quick (thankfully through integrity) that no one in my area would touch a motorcycle of my vintage, not to mention it was a Yamaha and not an HD. I did find a place that specialized in vintage Japanese bikes and they did do me right the one time I took the bike there, but $$$ and I am cheap. I joined here and read, read, read and listen to advice given. This site has made me a rather decent motorcycle mechanic for my 81 XJ650 Maxim, there is a learning curve, but asking questions until you get an answer that you understand is the key. (Read: no such thing as a dumb question).

I just can't believe that after listening to a bike crank for two minutes that someone can say "yep, that motor is shot".

 

Do you remember how much oil you put in it?

Did you ever check the level on the center stand? Too much oil can cause bad things too.

Perhaps post a short video / sound clip of it cranking so we can evaluate.

 

I would say investigate further before saying it needs a new engine. And a couple of questions that have already been asked that will help with the diagnosis. If you don't know the answer, just say I don't know, no big deal. To reply to a particular question simply click the left control button on the mouse and drag the mouse pointer across that text to highlight it and click reply when prompted.

So once again, do you know how much you added? This would help tremendously so there is no speculation as to whether the engine was run without sufficient oil to do damage.

This is a great clue also, you have a Computer Systems Monitor. If low on oil the "OIL" indicator should have displayed on the LCD screen and the Red Warning Light would have flashed to alert you.

It does sound terrible. My first thought is the reduction gear assembly gear bushings in the starter are toast, or the starter clutch.

How did you check them, did you actually check for spark?

Is this related to after the incident or something you just did earlier before having the issue?

 

Check your carb bowls - ultimately out should check your fuel levels. But for a quick check get a small container, crack open the drain screw (probably add a small hose to the drain port) empty the bowl into said small container, then empty container and repeat for all 4. All 4 carbs should fill to the same level in the small container.

You mentioned a dirty carburetor in your OP. Dirty on the outside? Dirty inside? Did you do anything to clean it?
It is almost Sunday, you may be looking at going to Church.

 

Did you read these links? ^^^^

This can (should) seems overwhelming to you. But with help from many here you can make this work! Methodically approach your bike, the first link above is a good over view. Don't be in a hurry, patience and proficiency will pay off.

 

Based on the sound:

she's making compression

the starter clutch has some slippage/kickback and I agree that the starter may be the major contributor to the noise.

the fuel mixture is close, but not close enough (she's trying to fire)

I don't hear any really bad noises that would indicate that the engine needs to be replaced.