XJ 1100 maxim rough running

Hello XJ bikes, I posted some problems with my XJ some while ago. After following advice given I imagined I had got the old girl sorted! What an optimist. With the yearly MOT test due I cleaned up and serviced the bike, all ready to go, only it didn't. Very difficult to start, plus on the road a complete lack of performance. This could be got round in a fashion by putting the choke on. I suppose this must be a carb problem, it seemed like fuel starvation. Although the bike has been stood for a while I did start it up every week and warm the engine up, also I had fitted line filters for the fuel, it has been starting on the button, no problem. I suppose its off with the carbs again, strip and clean. I also use a fuel additive.

The other thing is there seems to be a large amount of backlash in the transmission, in the middle gear. Is it possible to remove the middle gear assembly with the engine in the frame?

 

easy stuff first
How is the air filter?
fuel filters clean?
good flow on both petcocks?
how do the spark plugs look?
fuel level in carbs?
yes it does sound like you need to clean the carbs

 

You can remove the middle gearbox while the engine is in the frame. 4 Allen bolts hold it on. Some backlash is acceptable. Is it when you put it in gear and turn the rear wheel the slack shows up? But the middle gearbox is usually trouble free unless the gear oil has leaked out. Try changing the oil first, there's a drain plug underneath at the rear of the engine by the lower frame cross bar. To fill it there is another Allen bolt plug on top of the middle gearbox. These plugs are usually tight and can round off so what I do is to try and remove the filler plug first just in case the filler can't be removed and you end up with no oil in the 'box after draining, if that makes sense.
The 34mm Mikuni carbs on these bike do tend to gum up if left for a long period, and they will fire up and rev on the choke but try and rev it on the throttle and you're going nowhere. I've got a set in my garage off an XJ1100 that I was going to use on my XS1100 and they have got the problem that you're describing.
Have a look at this link> http://www.iwt.com.au/mikunicarb.htm if you don't know how Mikuni carbs work. You might find that just a general clean won't work and ultrasonic cleaning might be what's needed.

 

If the middle gear assembly is not making noise leave it in place. It won't benefit you to remove it unless it needs to be replaced. Just change the oil, use 85-90 gear oil. Change the rear drive oil at the same time with the same oil.

 

Regarding the middle gear backlash, yes it is with the bike in gear there is quite a lot of slack when you turn the back wheel. As for the running problem, I will remove and clean out the carbs. I will also change the oil in the middle gear and final drive. Cheers, Ric.

 

I reckon that's normal, what do you reckon mlew? I've had 4 XS1100's and an XJ1100 and they've all had some slack/backlash in the drive. The XS/XJ1100's all use the same engine/gearbox/middle/final drive except the cylinder head which is what Yamaha called the YICS which is found on a lot of the XJ series.

 

There will be quite a lot of slack at the rear wheel. There's lots of gears between the two ends of the power train.

 

OK, I will leave the middle gear alone, apart from an oil change, good to hear that I most likely don't have a very expensive problem. I took off the carbs today and found three of the slides seized. I have no idea why this is, its never happened before to any of my bikes, I always keep them covered in the winter, in the garage, and use damp traps to keep the moisture under control. Anyway, they cleaned up OK plus there was no dirt in the float bowls but I had them all to bits and blew everything through anyway. Is it just me or are they quite difficult to get on and off?

I have taken the opportunity to re-plumb the fuel lines, I don't know about anybody else (I don't know anyone else who has one of these, they are quite rare over here) but the fuel pipes are quite a fiddle to get routed right.

 

I use a hairdryer to warm the manifold rubbers and they slide on.
I'VE also got rid of the octopus, as its known, and run a fuel pipe from the left tap to the right carb feed and the other to the left feed. It's a lot easier to deal with.

 

Yes, All my 1100s have backlash , about 1/8 turn on the wheel when in gear. When you add up all the spaces in the gear train from rear diff to middle drive and transmission it is a good bit. Its only a problem if you run the bike at idle on the canter stand and put it in gear, sure makes the bike shake.

 

just looked at a picture of the "octopus" what a set up. did you interconnect the fuel lines and vacuum lines?

 

I did, and what a fiddle it all is, octopus is about right.

Having got the engine started and running nicely I found the clutch would not clear. Can I ask about oils? I run it for years on Shell advance mineral SX4, API SJ, motorcycle oil. This time the shop I buy it at told me "This has been superseded, buy this instead" What I bought was fully synthetic Shell Advance ultra, API SM, 10/40 the same as the other oil. Has this given me the clutch problem? and if so how can I cure it without new plates, over here in rip-off UK they would cost a small fortune. And what about running it on straight 20/50?

 

Is your new oil JASO MA compliant?
See the link in my signature for more info.

 

synthetic oil has been thought to give clutch and starter clutch problems can not say for a fact

I use shell Rotella triple protection T3 it is for diesel motors and JASO rated oil. I will be replacing with T4 because my local store no longer carries the T3.
a lot cheaper that buying oil with a picture of a motor cycle on it 13$ a gallon.

oil weights are temp dependent


SHELL ADVANCE 4T ULTRA 10W-40 SYNTHETIC OIL $17.50 a liter
• JASO: MA2
• Shell Advance 4T Ultra exceeds the requirements of all Japanese, European, Indian and Chinese motorcycle manufacturers.
• The product is endorsed by Ducati.

 

I just ran a fuel line from each petcock and don't use the vacuum lines, plugged them off, and so the carbs are basically running on the PRIME setting.
It has the extra benefit of letting you know when the float valves are worn as the fuel will then p!$$ out of the overflow.

 

and into the crank case

 

1. Over that past three years many synthetic oils have been able to achieve a JASO MA (or better) compliance and are not a problem for wet clutches.

2. Rotella T3 no longer exists. It was replaced by Rotella T Triple Protection, which has since been replaced by T4 Triple Protection.

 

Well, I've never had that problem yet, I've heard about it, but what I do is always always turn the tap to OFF when the bike isn't running. I don't suppose that with the engine running it would be a problem, so my other post about it could well be a load of old bollox.

 

The XJ petcocks have no OFF position. Vacuum operated petcock.
The trouble starts when the seals age. It's a combination of both the float needles, and the petcock leting fuel flow past the seals.
That can happen to any petcock, regardless of design.

 

That's not very good is it. I thought they were the same as the XS1100 Midnight Special. Do they have PRIME so it can run without the vacuum?

EDIT, I've just had a look at the part numbers for the petcocks for the XJ1100 and XS1100 Midnight Special and they are the same number, 3H32450001, so the XJ1100 should have an OFF position.

 

ebay link shows photo shows on prime res and off
http://www.ebay.com/itm/1982-Yamaha...ash=item51ad1c7066:g:2pMAAOSwyQtVlBv9&vxp=mtr

FSM also refers to turning petcock to off position to remove fuel pipes

 

DOH... you're correct. The XJ1100 is such an amalgamation of parts that I often forget which part came from where.

Even so, a worn petcock seal can cause it to leak, even with an off position.
I went down that road a few times.

 

Rick
To bypass the "octopus" use a piece of 3" fuel line with a bolt inserted in the end, and clamped, to block off each FORWARD petcock outlet. Route the fuel lines from each REAR petcock outlet to the carb. inlet connections. The run or on position will be with the petcock lever at the 6:00 position. The off position will be with the petcock lever at the 9:00 position. This will give you a positive fuel shut-off. Use a quality fuel line, the type with a plastic inner lining.

Dan

 

If possible keep the stock "octopuss" in working order. I see it like kind of a safety device to shutoff fuel in the event of a accident. Yes I do know they can be a PITA, but repair parts are easy to get and inexpensive. A kit with all parts to rebuild both petcocks and fuel valves less than 30$. I rarely have any problems with mine I don't see what all the fuss is about removing them.