XJ 1100 Maxim, bogs down intermittently under power

Hi folks,

I recently came across a gorgeous XJ 1100 maxim (1984, canada) with full vetter farings for a song and a dance. It hasn't been ridden much in the last 4 years, but has been garage stored. I'm in the process of trailering it home. While testing it out, I came across an issue that I am trying to wrap my head around (killing time while driving).

When taken for a test ride in town, the bike needed a bit of choke to get going, but seemed to be good once warm. Otherwise, good power, smooth shifting, and good handling.

While driving on the highway, initially good power and performance. After about 5-10km, the bike dogs out on me. Have to hold near WOT to maintain speed, feels like it isn't pushing all cylinders. Stop at roadside, quick inspection, nothing obvious; starts up fine, continues fine for another short distance then problem repeats.

It feels like my right two cylinders are hungry for gas. I don't have my toolkit with me, so couldn't do very much diagnostics. The rate of water evaporation from the YICS cover makes me think that those two cylinders are running hot (scientific, I know).

Discovered a crack in fuel line from the Right peacock, trimmed proximal to the crack and put it back on. Similarly, good for 10ish km and same problem.

If I limp her along to somewhere safer to pull off, I notice that she stalls out when I pull the clutch in (while rolling towards a turn off)

So as it is a new bike to me, I understand that I need to check the valve clearances, to church of clean the carbs, and to balance the carbs. But since I'm stuck with hours on the road, I figured this tgread would be a good starting point.

My suspicion is that I have to closely inspect my fuel petcocks and lines (and install an inline filtre). Any other tips or suggestions would be appreciated; sorry for not having all of my ducks in a row insofar as any other specific bike information.

Thanks

 

Sounds like you are on the right track. It may not be one single culprit but rather a combination of things adding up to your issue.

 

try opening the gas cap, it has a vent that can get clogged and no air in, no gas out

 

Dang it. I am almost embarrassed that I didn't think of the gas cap. Makes good sense.

I got her home last night, now I have access to my tools and meters. But first things first; test the gas cap theory, bring enough of a toolkit to be able to check plugs if I can recreate the problem, and watch exhaust header temps. I think the test ride may involve picking up the required materials to re-plumb the (new) fuel lines with an inline filtre.

 

I can't seem to find my hard drive with my XJCD on it at the moment, does anyone know offhand what the ID and OD of the fuel lines for a 1984 XJ1100? I think that I may have found part of the issue; there is a bend in the tubing that is just a little too tight, partially kinking the line.

 

That doesn't sound like a gas tank vent problem. That scenario is, you fill up, drive 5 miles just fine, then run out of gas.

Make sure your carburetors don't have an electrical issue. Check it by making sure voltage at the coils is equal to that of the battery. Weak spark masquerades as carburetor issue.

 

Fixing the fuel lines seems to have solved the power issues. Now onto the rest of the work. Thanks for the ideas folks; much appreciated.