XJ1100J has no power under load

I have a 1982 XJ1100J bike that starts easy, revs when in neutral but as soon as I put it in gear and try to move I have no power. I have recently rebuilt the top end including rings, gaskets and valve job. I got over my head and frustrated so it is now at a mechanic that has 30 years experience working on old bikes and used to race and do mechanic work for racers and his buddies. He is a good mechanic but even he is puzzled over this one. We have checked the obvious stuff. New plugs, checked for resistance, clean carbs, set floats, rechecked valve clearance. Any help or suggestions will be appreciated.

 

Welcome to the forum, lots of good people here and they will be along to help out in a bit. I too will throw my hat in the ring.

Have you had the bike on the center stand and tried to run through the gears with it running?

Did you do any mods to the airbox or change to pods when you did the rebuild? If so this will cause issues.

If the rebuild went well then I would think it would be a fuel issue if it has no power. When you cleaned the carbs did you really "Clean" them as in the church of clean? Most of the CV cabs really need to be broken all the way down and replace the rubber in the carbs. K-moe has great links in his signature block that will help you and your mechanic out.

Keep us posted and good luck.

 

Who? Me?

The XJ1100 has a vacuum-operated ignition advance. Check the vacuum lines for cracks (really, just go ahead and replace them).

See link below.
engine-loses-power-or-breaks-up-above-5500-rpm-runs-great-otherwise.94062

 

This bike had not run for quite some time and last year I finally got the carbs totally cleaned and it ran perfect. Just under 300 km and the #2 exhaust valve went through the piston. Took me until summer to get her all fixed up again. Quite sure the buckets on the valves were sticking which caused the problem. This year I checked the carbs and the mechanic checked them also. The air box is stock and in good shape as for running through the gears on center stand, not that I am aware of.

 

There is the clue. Carbs were done last year .. pilot jets gummed up and probably emulsion tubes as well

 

The vac advance on the XJ1100 is built into the igniter unit, it's on some of the XS1100's that the vac advance is bolted onto the side of the engine where the pick up coils are located.
I'd also check the cam chain isn't 1 tooth out on the sprockets if the engine has been rebuilt recently as well as Toomanybikes advice about the carbs being gummed up.

 

We double checked the timing and even tried to advance it some. double checked the carbs as well. On the floor in neutral it runs perfect, starts immediately and runs perfect until you put it in gear and try to move it. We are thinking it is the TDI box (spark advance). I found a post on this site explaining how to fix them. Has anybody had luck fixing them or am I better to buy one.

 

Just to be sure-
No power as in no Vroom, Vroom or like the Vroom is there and clutch is slipping?

If the former, and your carbs are Church clean; Was a running synch and colortune performed?
The later, rebuild clutch.

 

Maurice,
How many miles do you normally put on the bike when it was running well? I only ask because if you have to take the carbs off how much you drive it really matters. If the bike is sitting for long periods of time and then you just go to jump on it and ride it could be the carbs. If you have been on the bike every few days all summer and then all the sudden it starts to act up, that could mean another.

If the clutch is slipping it is normally under hard acceleration (at first). As you hammer the throttle in gear and the RPM's go up fatter then normal as you are accelerating, then your clutch is slipping.

 

I have not driven more than 300 km since I bought the bike but before the exhaust valve broke last year it ran good. This year after I got her all fixed the carbs were checked and were ok. The clutch is not slipping. When I put it in gear it bogs down as if it has no gas. I could barely climb into my trailer to bring it home. Checked all fuel lines and petcock. Lines were all replaced and petcock rebuilt a year ago. Tank was also relined with epoxy.

 

I'm with Stumplifter sounds like a slipping clutch...are you running synthetic oil? If so this can cause slippage if oil was previously conventional ....just throwing it out there. I have a buddy he has an 82 maxim 1100 with Kawasaki ZX1100 carbs it is a beast .

 

Maurice,

I can only say that I would give it a full check, compression, plugs and works and then I would pull the carbs again. I know how fun that is but if everything else you have checked is good then it is pointing at fuel. I don't know how long it has been sitting sense you did the top end, new piston (if that is what was needed when you threw the valve). It could be that the rings were not run in and could use a little oil in the cylinders?

Those are just the things I would check, but if you think it is fuel then if you have checked the petcock and the fuel lines, you will have to start looking at and around the carbs, boots and vacuum lines.

 

Are your brakes seized on? Do the wheels freely spin?

 

I checked all that and are good. I was able to push it on my trailer no problems

 

If it is spark advance related then repairing would prove difficult sourcing the correct parts, or knowing which parts to even replace. The most common repair is a dead channel caused by a defective output transistor (2 dead cylinders) or a totally dead TCI caused by obviously damaged discreet components or by corroded / open connections.

So do all four pipes appear to heat equally? Does the enrichment circuit improve power? Fuel level in the bowls verified? Ignition voltage verified to rule out weak spark caused by low voltage in the ignition circuit? Checking at the TCI should suffice for the ignition voltage check.

 

All four pipes heat up the same. I have the burn mark on my forearm when I was checking them.
Fuel levels were checked and were ok.
I am quite sure my mechanic checked the ignition voltage as well.

Has anybody tried and had success repairing the TCI

Thanks everyone for all the suggestions. They are making me double check all the possibilities.

 

Good evening, so I purchased my 1982 xj 1100 2 months ago, it already had filter pods which I'm not crazy about, im a beginner, never really worked on a bike before. Bike wasn't running well. I purchased the ycis eliminator installed that put stage 2 jets , drilled the weltch plugs and adjusted the fuel air the bike ran for a couple weeks . Not great but well enough to ride. Now I'm having the same problems you described exactly. Just wondering if you figured it out? Any help would be great as I'm pretty frustrated at this point. I can't find anyone willing to work on my bike.

 

Hi mate,
i would get the fuel and air system back to standard by putting on a standard airbox instead of the pods and re-jet the carbs back to standard.
I've had a few sets of XJ1100 carbs and don't know what these welch plugs are or even where they are on XJ1100 carbs. Hope you've not fooked them up!

 

Jumping in here if no one minds. I require more info. Were the lower cases split? Does it die when put in gear? Does it shudder when in gear and accelerating?
How crisp and responsive is the neutral revving?

 

Last seen 2018...
Given up, sold or fixed and couldn't be bothered to tell us......
Aaand, @Wayne1986 , who now has taken up this thread has said he has ridden the bike since modding it, and then the problems occurred later.so returning everything to standard won't fix it?

 

Ahh...

 

I appreciate the reply, wish I could turn back to stock would prefer actually, I purchased it like this if I could locate original parts that would be great been looking haven't found yet

 

The filter pods were on the bike however I did the other the jets and the ycis eliminator