82 XJ Maxim Vacuum Hose

Well, yes--- BUT the one end is hooked up to the vacuum port on the petcock and the other end will be hooked up to the s0urce of vacuum.....'whether it is your m0uth, or a one-person bleeder, or the engine intake vacuum port. Either way you should not get any gas in your mouth. If you DO, then the diaphragm is ruptured. The vacuum is on one side of the diaphragm, the fuel is on the other. T he vacuum pulls the diaphragm back to allow the fuel to flow PAST it, not thr0ugh it.

 

Gotcha, I had just misunderstood what XJ550H had said earlier. I’ll give it a shot tonight!

 

I’m getting fuel in on position. This was confirmed when I did the petcock test you guys mentioned. Got it started, no choke, no gas. Idling Very high. I almost can’t let it idle because it’s as if the throttle is pinned. There is slack in the choke and throttle cable. None of the arms on the throttle linkage are engaged when this was happening (see pic). My only thought is maybe carbs need to be re synced but not sure why it would start that high when the carbs aren’t very out of sync.
Maybe I should play around with the idle screw, but I don’t think it was tightened very high. At least not enough for it to start that aggressively.

 

Is there a standard amount of turns the idle screw should be off of a light seat?? Ex: 6 turns off of a slight tight fit, etc.

 

Idle speed screw gets adjusted to where you want it.

My first question now is: "can check to make sure the throttle cable and enricher cable have not inadvertently been switched...... throttle to center so it opens butterflies, enricher cable to top rail so it opens enricher plungers"

 

And push down on the enrichment plungers to see if that drops the idle.

Baseline for the idle mixture screws is 2 1/2 turns off a soft-seat.

Baseline for the idle speed screw is done when you complete the bench synch, but may need to be backed off as the bike warms up, and as you complete the running synch.

 

idle adjustment screw is the knob that is in the back of carbs between carb 2 and 3. it should be touching and moving throttle linkage to set your idle no soft seat.

the idle mixture screws are set as k-mow stated . there are 4 of these at front top of carbs


I am just clarifying the t different items

 

Idle mixture screws set properly. The throttle cable and enrichment cable WERE switched. That explained quite a lot. To be fair to me, they were switched from the time I got the bike until about 30 minutes ago. But I should have used common sense and caught that they were hooked incorrectly.

But, I have some good news for once on this thread! Cold start with the choke on a bit, it fires up! Not having that insane idle issue anymore, which was obviously due to the cable mixup. The carbs 100% need to be synced, I can tell just by hearing it. So that is going to be my next thing.

Thank you guys for the incredible help. I’ll keep the thread updated on the sync etc

 

Bike now starts without any starter, idles fine. Only now, when I give it some gas, one or two of the carbs seems to make a “puff puff puff” type of noise before it starts making a decent revving noise. And then when I put it in to gear and try to go, it sorta just puffs out and dies. Any thoughts?

 

-Verify that you are getting spark on all 4 plugs
- have you running-synced the bike yet

 

Hey all, it’s been awhile.
Not long ago I put the carbs back on the bike after syncing them, bike starts with the choke on but I’m still having problems when throttling the bike.

If the choke is ON, when I give it gas it seems to rev normally.

If the choke is OFF, while idling when I try to give it gas, it puffs out and dies. Any ideas?

 

How long are you letting the engine warm up before attempting to ride?

 

K-moe, it ran for probably 2 or 3 minutes (choke on, no throttle) before I tried giving it throttle. I was not on the bike ready to ride when I was giving it throttle, bike was in neutral.

After the 2-3 mins, choke off, the bikes dies. This led me to believe the idle needed adjusting so I tightened it, no change.

So with choke on, I give it throttle and it revs normal.
With Choke off, it either idles really low or dies, and if it’s idling low, it dies when I give it gas.

That just sounds like an idle adjustment problem doesn’t it?

 

The normal course of events.

1. Start bike with choke (enrichment may not be necessary for initial startup in warm weather, but that does not mean the engine is warm enough to be ready to ride). No throttle should be used, but may be necessry if the idle speed is set too low or the idle mixture is incorrect, or the fuel level in the float bowls is too low.

2. Wait for idle to increase to around 2,000 RPM.

3. Reduce choke to lower idle speed to ~1100 RPM (bike can be ridden at this time).

4. Aproximately 5 minutes later the engine will be at operating temperature and choke can be shut off entirely (may take a bit longer on cold days).

It may be an idle adjustment issue, or it may be a lack of familiarity with the XJ.

Idle speed needs to be set after the engine is fully hot (after at least a 10 minute ride), and you will benefit from it being around 1200 - 1500 RPM at that time (this helps with cold starts).

 

Thanks for the great info K Moe. I’ll give it a shot tomorrow!

 

If it still does that, then it's an indication that you are running only on the enricher and you are starving when you try to go to the main Jets. Could be clogs, or fuel levels, jets mixed up, etc....