Perplexing problem - can anyone help?

[maleko89]

X, sorry for not being clear.

The manual is wrong. You need to measure from black to each of the four coils. So, black-orange, black-gray, black-white/red and black-white/green.

 

[Shuriken]

Thanks. I will definitely check that out today.

 

[maleko89]

LoL, were you offended I called you X? Is that the reason for the name change?

 

[Shuriken]

LoL, were you offended I called you X? Is that the reason for the name change?

LOL... no.... but the old username was one I derived from my posting status from the XS11 forum..... and it was too long.... plus it started sounding like the part of the body....

 

[Shuriken]

Temp is about 85f. Elevation is 5700.

Boost sensor test: 2.18v
Manual calls for ~2.0v

Pickup Coils test at connector:
B-O: 119.9 ohms
B-W/R: 120.4 ohms
B-Gray: 121.6 ohms
B-Whi/Green: 120.5 ohms

Manual calls for 110 +- 10%

 

[maleko89]

Those test numbers look good. Manual states readings are for 68*. Resistance will increase a bit with an increase in temperature.

 

[Shuriken]

Well... I'm at a loss, then. I thought for sure it would be something obviously electrical. If it is still an electrical problem, I'm betting on the TCI box under the steering head.

If it turns out to be a fuel problem, well, I'll find out sooner or later because I have vboost manifold o-rings and rubber manifolds, vacuum port caps, rubber carb manifolds, and rubber velocity stacks. Will also check and replace the fuel pump. When the carbs are off, I'll go through them again.

While I'm waiting for the carb parts to show up, I may as well proceed to test the TCI unit.....

If TCI checks out, about the only hope left is that it is a fuel issue, which I hope to solve with the carb parts, cleaning, and filter.

 

[gleno]

Well... I'm at a loss, then. I thought for sure it would be something obviously electrical. If it is still an electrical problem, I'm betting on the TCI box under the steering head.

If it turns out to be a fuel problem, well, I'll find out sooner or later because I have vboost manifold o-rings and rubber manifolds, vacuum port caps, rubber carb manifolds, and rubber velocity stacks. Will also check and replace the fuel pump. When the carbs are off, I'll go through them again.

While I'm waiting for the carb parts to show up, I may as well proceed to test the TCI unit.....

If TCI checks out, about the only hope left is that it is a fuel issue, which I hope to solve with the carb parts, cleaning, and filter.

Don't forget to test the pressure sensor. It feeds the TCI box with the advance / retard info.

 

[Shuriken]

Don't forget to test the pressure sensor. It feeds the TCI box with the advance / retard info.

Thanks Gleno. I thought the pressure sensor was the boos sensor? If so, I've already checked that.

 

[KY_BOB]

I DEFINATELY don't proclaim to be a motorcycle mechanic but is it possible that it just running out of fuel at periods of high demand due to either a clogged filter or a weak fuel pump?

If one of my old street/strip cars acted like that, that's what I would suspect.

Just my $.02.

 

[richwrench]

This may be a long shot, but it worked for me & it's FREE !!. Take off your scoops & steering neck covers - take apart every single electrical connector you can find, spray with contact cleaner, apply with di-electric grease & re-assemble. I had one helluva intermittant mis-fire problem that was corrected after I did this - but in my case the PO had left the bike out in the weather for a few years. Ignition switch was especially bad - GOOD LUCK !!

 

[Shuriken]

Got boost one time tonight on a test ride with the airbox off - and it wasn't because I cleaned, lithium-greased, and reconnected all of the electrical connectors or installed a new fuel filter... at least I don't think so.

I was riding with the airbox off and started covering intake ports on the carbs because it sounded like #1 and #2 were drawing more vacuum than #3 and #4. I then covered each carb, one at a time, with the palm of my hand and revved the engine. I was able to feel the suction of each carb and see how much fuel was on the palm of my hand. After I did this on all 4, I then got on it for a half block and boost started to kick in.

I took the bike home, put on the airbox, and went up the road again. No boost this time, just the same old flub.

At this point I do not think I have mechanical or electrical problems. I'm going to go back to focusing on the carbs. When I get my new air intake boots, vboost boots, and carb boots, I'll yank the carbs and methodically go through each one all over again.

Anybody have any thoughts now?

 

[maleko89]

Do you mean that you could give it more than 1/2-3/4 throttle with the air box off? If you try it with the bottom part of the air box on but w/o the lid what happens? I would say it's a problem with your carbs and/or air box....possibly bad boots somewhere. With the air box removed you lose velocity so it leans you way out. Do you have stock carbs? If so I'm surprised that you could run it w/o the air box.

 

[Shuriken]

Yes, stock carbs and airbox. Remember I am at 5700ft elevation, though, and the muffs are drilled.

I did the first ride with nothing on the carbs... no velocity stacks, no bottom of air box, and no top of airbox or filter. Just up the road and back about 2 blocks. Normal start with choke, let it warm up, etc.

Yes I could give it more than 1/2 to 3/4 throttle. However, as I said, it really wasn't until I blocked the carb intakes (each one in order), before I gunned it and vboost kicked in. I didn't try to hammer it before I covered the carbs. Yes, with the airbox off, I should be really lean. It felt that way for a block.

I think when you cover the carb intake port and rev the engine, when the RPMS come back down it creates a strong vacuum that would normally pull the air through the carb. But since my hand is there, I think it pulls more fuel and goes rich (palm of my hand is coated with fuel/vapor). Did that to each carb and then let it rip and got some boost.

At least feeling some boost was encouraging. I *really* hope I get boost back by going through the carbs, installing the replacement parts, then synching. If not, I may park it in frustration and come back to it next summer....

 

[Shuriken]

I installed the new velocity stacks and made sure they had a tight seal against the carbs. Took the bike out for a ride. Still flubbs.

Carbs come off later today. If I can't find anything wrong with the carbs, I think the only other thing left would be to replace the TCI box.

 

[Shuriken]

Earlier today (and yesterday) I replaced the V-Boost boots, intake manifold boots, and air intake stacks. I also removed and went through the carbs again. They looked pretty clean. Reassembled. Boost kicked in but the bike is sputtering a bit. I will see what a synch and idle mix adjustment will do tomorrow.

 

[Shuriken]

The beast is back. Been awhile since I've been able to ride. She got up to 95 real quick on boost before I started slowing down....

I *think* #1 main jet had come loose in the float bowl. This was one thing I found. I *think* there were some clogs in some air passageways also. I used compressed air and carb cleaner liberally.

Of course I replaced all the rubber bits externally. Next time in the carbs, I need to replace the jet block end plugs and float bowl gaskets. I did replace main jet o-rings and the o-rings underneath chrome carb tops.

 

[Shuriken]

Bike flubbed sporatically today again and then recovered. Got to be an electrical issue, like TCI box....

 

[maleko89]

I agree. When it's sporadic like that it's very difficult to troubleshoot.

 

[Shuriken]

Happened again today. Feels like 2 cyls drop out on me and the come back. Are all the TCI boxes from different years interchangeable?