Hi there,

I'm a new Xj owner. First bike. First time on the road in fact. Had it about 2 weeks now. I'm more a computer tech than an automotive person though, so I'm feeling pretty lost with what to do here.

I bought the bike from a used bike dealership. Its the 1980 650 Maxim I, in nice shape from all appearances. 31,000 km.

It seemed fine in the first week. Started ok, no problems in fact. But by the end of the first week, it suddenly started chugging out on me one afternoon. I racked it up to it taking a beating from rain that morning. I topped up the tank to full. Seemed ok after that.

Now its a week later. I've done 150km since filling the tank, and again, its chugging and outright dying on me at intersections. Extremely embarrassing you know? Everything I read about the XJ says I should be getting 300km to the tank right? I hear fuel in there sure enough, but I'll bet when I hit the gas station for a fill, it takes no more than 10 bucks again (as it did last time). Thats only 10 litres of a 19.8 litre tank. Something else is going on.. but.. I'm too damn new to know where to begin to look.

While idling, it does seem to make alot of "pops"/backfire. It didn't in the first week, but does now when running well or not.

Any help would be appreciated folks. Its my only means of transportation, else I'm back to ankle express. It took me years to finally hit an income (2 kids to care for first) to just afford this thing and now its like crap.. 2 week trial, yer done.

Paul

Um - I also have a 650 Maxim, mine is an 1981... much newer ;)

As for how far I can go on a tank - I consisitantly hit reserve at 140 if I'm blasting on the highway, 150 under normal conditions, and 170 if I baby it because the rear tire would blow if I didn't.


I think that you are out of gas - switch to reserve and fill it up. If you put in about 10 liters you drainined the top (main) part of the tank - if you approach 13 Liters then you almost drained the whole tank.

Maxim 650 Tank size:
10 Litre main
3 Litre reserve

Maxim 750 tank is what I'd like to buy as I think it has a total size of about 21 litres... much much better for long distance riding.

Cheers,
woot.

Hey there..

Are you sure about that tank size? I mean, I've gone over a bunch of sites on the net to dig up anything I can on the tech specs for the bike, and what I find is that its supposed to be a 19.8L tank on the XJ650. For example, this site:

http://www.lebell.ca/xj650/maxim.asp

Shows this notes about the miles this guy gets on his XJ as follows...

7/24/2005
I came across a discussion forum for XJ Owners and was reading an article on gas mileage. Based on the average gallons per mile that was referenced for the xj650 I came up with the following for my bike. The reason I have chosen the two locations below is I live near Trenton and I always make trips into Toronto.
Approximate distance Trenton, On to Toronto, On
160 Kilometres

Fuel tank capacity
19.5 Litres

Cost to fill the XJ
.89*19.50 = $17.35

Mileage per 19.5 Litres
367 Kilometres

Now.. part 2 update..

I had the pleasure of getting some review/feedback from a guy who's been riding/working on bikes for a long time. I tell ya, I learned more about my own bike in 5 minutes than I've learned from reading stuff on the net the past couple of weeks.

Within 60 seconds he found an exhaust leak. A few minutes more, he showed me a way to check for rust in the tank with the loosening of a couple of screws.. and there was a slight tint/indication of rust. He pointed out the need to probably replace the seal around the gas tank latch as it may be letting moisture in. I was really impressed and surprised by the things I didn't have the eyes/experience to catch before.

So, it looks like I'll be making a trip back to the dealership I got this thing from to address the exhaust issue at least, because it never should have passed safety (which they did the certifcation for). I doubt they'll budge on a few other items I'm going to mention. But if they really drag ass, I'll be filing complaints with the Better Business Bureau on their business practices. Fumbling and fudging safety certifications is absolutely deadly and not acceptable.

Any other input is still welcome folks. In was in a another forum elsewhere and saw similar questions to my own. I directed those posters to this site as backup info. Thanks for the reply so far. If someone can state definitively the tank volume for the 1980 xj650 it would put my mind a little more at ease.. because now I have conflicting information from what seem to be reliable sources. Arg!

It might be a waste of energy to go after them for the exhaust. There's some pretty wide open systems that get passed every day, plus that's a major expense for them to dish out. That is unless they offer to weld a patch which is unlikely.

Have you been setting the fuel petcock to ON and not PRI? Te former is for regular use; the latter allows fuel to flow freely sometimes causing problems like that.

If there's rust in your fule you should consider getting the tank lined. In any event you should install a small fuel filter between the tank and your carbs.

Cheers!
John

It is possible the bike has a non-stock tank. I can assure you that my tank is 10-3... I just put 20 tanks of gas in it to go to NY! :D I had to test your theory.

I got out my owners manual - definately the 650 maxim in 1981 had a 10-3 tank... the 750 on the other hand had the larger tank you refered to.

What I'd suggest you do is get a can of gas - put some in the tank and see if it starts to run better... it really is very likely you are at reserve, or about to hit it.

For giggles - you could always turn the petcock to reserve now and see if it runs any better. Might take a minute to sort itself out if it has been run empty on main for awhile. ( takes a second for the fuel to fill up the carbs again - they're probably nearly empty and having a hard time getting fuel - causing your bad idle)

Exhaust leak - I have one too - if it isn't too major then don't worry about it. It's the bikes way of saying I'd like a new set of cans please... :) Assuming yours is leaking at the cross over or the end cans - a gasket style leak is fixable - pin holes suggest that the pipe is rotting away and will need replacing in the next year or two.

Rusty gas tank - if it is just a red smear then it is likely been let sit low for awhile and it isn't anything really bad - if it is scaley then it has set into the tank. In that case you will have to seal it to continue to use that tank - or - consider ebaying a replacement tank... as that tank if it was starting to rust in a structural kind of way won't last forever.

If the bike does have a fuel filter - check it. At the same time check the fuel bowls. This will tell you if the bike is out of gas and/or is letting crap from the tank into the carbs. There is a little screw on the bottom of the carbs next to a drain spout - put a cut off pop can or some house onto the spout loosen screw and let a bit of gas drain out - look for particles. Some particles are normal - alot of particles suggest that you have a particle source such as rust.... this also drains out the fuel for winter storage...

If it didn't have a fuel filter consider purchasing one - can save problems on the road!!! If it stops without a fuel filter due to crap in the carbs you can pull the fuel filter off and limp home. IF you fill a fuel filter with crap and are miles from home you can pull the filter out of the system, limp home and get a new filter.

Cheers,
woot.

I can attest to the tank size also. I get 100 miles before it starts to stumble, and then another 45 before she goes dry. When it starts to stumble I flip to reserve and pull into a gas station. Fill-ps are usually 2.5 gallons - equal to your 10L. It does seem a short distance between fill-ups. I'm looking for a larger tank, either a 4.4 or a 5.2 gallon. Both are interchangeable with our bikes. The 5.2 is really funky lookin' on a standard Maxim, but the 4.4 is a larger tear-drop like the original. That's an extra 45 miles/70km!

Later

Which is the 5.2 from? The 900 or 1100???
The 4.4 is from the 700/750 correct?

I seriously would have loved to have had that tank this year - stopping every hour to get gas was a pain!!! I rode about 40 hours... that is way too many gas stops for anyone.

Your Carbs need rebuilt and tank might need lined. The popping can come from the pilot jets being plugged. Might want to check your intake boots and petcocks also. If you do these things it will run forever hassle free.

Carbs may need flushing through. If the bike had been stood a while, there could be water in the fuel lines. need to prime right through and bleed the float chambers off in the carbs. Have you an inline fuel filter? yes , replace , no, fit one. Change the fuel pipe at the same time.

Get a gunson kit and check the sparking.

Holes in cans are not good either, xj's seem to like a bit of decent back pressure , especially when cold.


Old bikes are good fun , always plenty you can check and do something about.

Kicking helps occasionally as well. just need to know where to kick it.

Seriously guys - at 150 km he is out of gas and needs to switch to reserve and get more gas.

I haven't head him post back to say what happened - perhaps there is more to the story that we haven't heard yet.

Xj's liking back preasure - yes - if they are tunned for the stock pipe they won't work well without the back preasure. What we're really talking about is that the pipe flows better with holes. If it flows better it tends to run lean - make it cold and it runs even leaner. This is why xj's (or any non-injected bike) don't like the pipes getting holes in them and running freer.

This persons problem is lack of fuel. If they have a non-stock tank then there might be a different problem... but we haven't heard back to say otherwise.

Sorry for seeming cranky - but lets go with the most obvious and simple solution first. I image that they are embarased that was the problem and haven't come back. It's nothing to be ashamed about, we've all run out of gas and thought something else could have been wrong - hell just the other day I did it coming up to a light - had been running off for awhile - and I passed it off as running rough because I had left the choke on too long... oops.

Cheers,
woot.