Two concerns...

Hi, folks. I'm a relatively new owner of an old Maxim ('82 XJ750J). I bought the bike a couple of months ago from the original owner. It had been stored since '95 and has just over 15k miles on it.

My 1st concern: How do I remove the handlebar stopper bolt? I'd like to change the horizontal adjustment of my bars. The factory manual says to remove the handlebar cover, bolt cap (broken off), handlebar stopper bolt, and handlebar pinch bolt. The stopper bolts are round with no apparent contact points for a wrench. Do I use vise-grips or such and mangle these things or is there another way to remove them that I'm not seeing?

Second concern: The engine starts easily and runs fine when warm except for an apparent flat spot when cruising at lower rpm (below 4,000 or so) and minimal throttle opening. If I nudge the throttle, power comes on quickly and acceleration is strong up to redline. In a fuel-injected vehicle, this would be called a 'tip-in' flat spot. Unfortunately, I understand FI far better than I do carburetion. Is there an off-idle or partial throttle circuit I should be looking at or is this a sync issue? Response is largely instantaneous when I crack the throttle.

Any help would be appreciated.

 

Sorry for the double post.

 

My throttle responds the same way. It can be hard when you are cruising at low throttle openings and you hit a dip! 8O I have really solved this problem by relaxing my hands and arms during riding.

From what I understand, that is just the nature of the beast for ANY motorcycle. Someone please tell me otherwise, because a smooth power delivery is much better for rider confidence.

 

Well I know who to ask about FI now! The throttle issue is most likely a slightly rich mixture. For ge tabout how FI works and remember that these are CV carbs with no fuel pump external or internal like Holleys. So when you nudge the throttle air rushes in. These carbs are completely dependent on the venturi to bring fuel up from the carb bowls. So a nudge adds a rush of air to burn latent fuel. Sligtly backing off the throttle at speed will produce a power surge if the mixture is lean.

Have you changed the air filter? This may solve the problem. Other than that and sparkplugs it would be the carbs. A sync couldn't hurt. There are some XJer's in San Diego and if you want a road trip an annual carb clinic in the San Francisco bay area.

 

The air filter is a new Uni foam filter. It was oiled, drained, blotted...and I took the filter out briefly to see if it would make a difference. Nada. I'll pull the plugs next to check for richness or oil. I hope I don't have to pull the carbs. Just getting the airbox out looks almost impossible.

 

when is this anual carb clinic in SF bay?

I might actually want to make that road trip :-D

 

Weavalo:

Getting the airbox out is nigh impossible, but thankfully you don't have to remove it to get the carbs out.

See posts a couple of weeks ago about the proper technique.

Good luck!
Herb

 

I've found that the airbox comes out easily if you pull the starter

 

Get rid of the Uni Filter and put in the stock paper filter. When I bought my bike it had and Uni Filter and provided way too much air and made tuning the carb almost impossible. I installed the OEM paper filter and things got better instantly. As far as the air filter, carbs, and exhaust, trust the engineers that built the bike--keep it stock.

 

You guys know this thread was 15 years old?

 

People read old threads all the time. Updating them with better information than we had back then isn't a bad thing.

 

No but it is funny when it happens....

 

I didn't even notice until you mentioned it. Guess he got it fixed back then.

 

r/e removing air box. I pulled the air box by removing the starter and carb holder boots,
wiggled it to almost out, then bent the last 3/4" around the frame and it popped out . Could
put one back the same way.