possible stupid oil question

Change your oil right away and tilt the bike as far forward as you can to remove as much oil/gas as you can. Sounds like you have a carb flooding issue so you will need to get your carbs good and clean, bench synch them, then dry set and wet set your float levels. Check your valves, adjust if needed (not as hard as it sounds) then you can synch your carbs and you'll have a nicely running bike. Sounds like a lot I know, but believe me we've all been through this and there are no short cuts. Once this is all done properly you will only need to do basic maintenance.

You don't want to run it with gas in the crankcase it will damage your clutch among other things. Have you checked your brakes? Back for delamination and front for old hoses? Danger lurks there if they are not right. You've found the right place to fix it, but there are NO short cuts.

 

thanks bud...and no i have not checked my brakes...jus got the bike..

 

how do you bench sync them and do i need a certain tool to set the float?

 

First welcome to the site or XJ World as it truly is. You have found the best source on the net for these bikes and for advice in general when it comes to doing the work yourself. And you will want to as shop's are expensive and often clueless when it comes to these older classics.

Most of the time the front brake hoses are original and their design life is 4 years, the rear brakes have been known to DE-laminate, or separate from their linings which will instantly lock your rear tire. This is especially true on bikes that have sat for a while.

Carbs: your best bet is to enroll in a self taught class known as carbs101 or as it's called here "The Church of Clean".

Check out these links:

http://xjbikes.com/Forums/viewtopic/t=31061.html
http://xjbikes.com/Forums/viewtopic/t=2908.html

Fitz's link details the same carbs on your bike and mine.
Rick's 'whole nine' is long but it pretty much covers the procedure.

Basically your carburetors have a float that seats a needle when they rise to right level to stop the flow (kinda like a toilet) and either they are set wrong or you have worn out parts. This causes the flooding into your crankcase. So they must come off the bike and get the 'whole nine.'

Bench synching is done after cleaning and replacing any needed parts. This is setting the butterfly's to just barely open to allow your Pilot circuit to feed the right mix of air/fuel to idle. Mostly you only need a good set of basic tools, but there are few special ones to do the whole process, but nothing that is crazy expensive. Read the links, start your research and ask any questions you need to.

Believe me there are no short cuts, but when you are done you will be amazed at what you can do and have learned.

You should turn on your location feature and put your bike's info in your signature line so the help you get is on topic and if anyone is near you they may be able to come help if need be.

 

83 xj750 seca petcock on/off
how do i get petrol in the oil

 

stuck float

 

PLEASE use motorcycle spec oil in an air cooled motorcycle engine, unless you like changing clutches. According to Yamaha, car oil has friction modifiers in it that coat the clutch plates- air cooled motorcycle oil does not have these additives. Instead it is formulated for the much higher temperatures encountered vs a liquid cooled engine.
[retired Yamaha tech]
:wink:

 

+1 Not "please" more like GOTTA.

It tends to be a self-regulating issue. Put car oil or a full synth in there and the starter (sprag) clutch won't work right any more.

Thankfully, JASO (motorcycle oil specs) were developed some years back; it's just a matter of spreading the word.

I don't think it's even a case of "coating" the plates; the stuff is just too damn slippery.

That being said, Castrol makes a line of SEMI-synthetic, motorcycle specific oils that I've been comparison testing and can highly recommend: http://www.castrol.com/castrol/sectiong ... Id=7079437

Kind of hard to find (I get it on-line) but the stuff really works. No clutch or starter clutch issues and virtually zero oil consumption.

 

back in the 'olde' days that's what we used to tell customers because it was easily understandable. I've seen car oil do all kinds of strange things to MC engines... 8O

 

@raptor8

Pray tell... I can't say that none of my motorcycles has ever gone wrong and I'm back on the site because I suspect my poor old 550 has a rattly hyvo chain and guide, but that's a design fault and not down to oil. I use automotive synthetic oil whenever possible and my bikes manage pretty high mileage, mostly in either heavy traffic (London commuting) or heavy use (sidecar pulling a trailer tent), although my right hand is quite restrained. With regular synthetic oil changes (I used to do that every 1-2,000 miles, but now leave it longer) I hardly think about the engine wearing out.

 

I change the filter every time I change the oil. The oil viewfinder is kind of a weird way to check your oil. I've over filled it several times because I couldn't tell where the level was. Just recently, I thought I blew the motor as oil blew out the breather hose all over the bottom of the bike. I seen oil dripping(after hitting 8k rpm in 1st through 3rd) from underneath. I bought a quart of oil from someone at the bar we stopped at and figured I'd stop every 5 miles to put more oil in it. The 1st stop, no oil dripping and the oil level was just visible at the top of the glass. What a relief I didn't blow the motor after all! Luckily, it was from it being over filled.

 

So... Probably a silly question. I recently recovered a sitting siezed engine and had to do the frequent oil changes. Is it necessary to change the filter each time? I have been but it's a hassle?

 

i'd do every 2 or 3. did you ever split a filter open and see what it's catching?
how long are you going to do these quick oil changes?
Mobil Delvac has been working in my stuff for years, and it's cheap

 

Probably at least once a week for the rest of the month. I'm less concerned about what the filter is catching than what it isn't. Finding a decent amount of rust bits in the used oil. Getting less and less but still some.

 

Wow I never knew about that drain either. Thanks for describing it as it makes it allot easier to look for it.

 

Careful not to break that little bolt off. The one that's been in there 30 + years.
Then you'll be pissed.

 

I don't bother with the middle drain plug. Enough oil gets changed that I'm not going to worry about a cup of oil. It get's into suspension and gets drained at the next change anyway.......

 

very good thread I just joined the xj club cant wait to read up on old posts and learn! -83 XJ750M Midnight Maxim

 

On the dark oil do not worry that actually means the additives in the oil are doing its job. At least on cars thats true. I'm going to say it's the same with bikes. But basically it means ur oil is working. There is what people call detergents and as the oil hits the additives do its job and breaks the detergent down causing the oil to look a lot darker. That's y don't ever let a mechanic tell u any of ur fluids are dirty and need to be changed. Bc they can change the fluid and it can still have a similar color.