power boost vacuum advance unit

[carsick]

Fuckin' A, the sexual tension in here is unbearable. Just get drunk and bang each other already.











Damn 1100 owners, always gotta be right. It's that 5 horsepower thing I think.

[Dan Filetti]

 

[rexsk8er]

I'm curious to see what happened with saltyfj1200rider's bike and if replacing the TCI unit was a fix to a surging idle in this particular situation.

I'm seeming to encounter the same issue upon actually riding my bike. Its a 1985 FJ1100. I have a post in mods listing jetting but its not the lean stock stuff, only adjustment not set is the needle and will be soon but that will not contribute to an idle issue. Not trying to steal a thread I only want to contribute any info possible.

I spent all day chasing all the vacuum leaks and can only get my idle to settle at 1k if the vac line is unplugged.

I replaced the only manifold that had any dry rot cracks (very small at that) and got some new hose clamps and o-rings. The clamps are not the right type but after a little fiddling I manage to make everything seal, I get NO variation in idle upon spraying with carb cleaner.

Not to mention having the carbs on a set of synchronizers for the duration of leak-checking. No variation before and after, Im sure the leaks were minimal at best. Of course all sync'd off #3  as its the idle adj. so 4to 3 than 2 an 1 to 3 all are spot on the exact same through the rev range and on de-cel (useing actual gauges, not fond of replacing mercury)

No binding whatsoever of throttle issues and all chokes close 100% (test by spraying choke seal directly with carby cleaner) Possible that there is leakage past the choke seat inside the carb, so my next step, before installing aftermarket ignition or another stock TCI,  is to use a vac pump on the choke air feed lines and make sure that they seat 100% but like I said I'm sure they do.

But the biggest clue so far is for whatever reason THE TUBE THAT GOES INTO THE TCI ITSELF IS VERY LOOSE I/E COULD POSSIBLY BE PULLED OUT BY HAND. I don't mean the vacuum hose, I mean the fitting the hose slides on that is built into the ignition box.  I'm sure there's a vacuum leak inside the box itself considering that piece was so loose. After noticing that I'm going to spend $50 to buy a new rotor for the dyna2000 sitting on my shelf.

Tomorrow I will go to the shop and pull it back apart. I just put on the body (whole faring) pics in my other post. But for tomorrow's agenda Vac test choke air inlet, vac test tube going to TCI itself, and than try another stock unit laying around the shop. We maybe even have a newer one with the external pressure sensor. I'd prefer that over the built in one.

I guess I could go on forever I'm a motorcycle mechanic by trade, so I'll plug away until the solution presents itself. Process of elimination. I'll report findings ASAP

Sean

[saltyfj1200rider]

I am sorry for not updating my troubleshooting info. being new to FJowners.com I was disappointed at how foul some of it's members can get! I replaced both the vac advance unit and the intake boot o'rings (flat but not cracked) at the same time. I can not be sure which solved my problem, but I checked for a vac leak earlier and did not detect any. My idle still hangs vary slightly (barely noticable). I think now sinc carbs and idle mix adj. will fix any remaining issues. For a 22 year old bike, it is AWESOME!

[1tinindian]

I am sorry for not updating my troubleshooting info. being new to FJowners.com I was disappointed at how foul some of it's members can get! 

We're all big boys here, not to worry.
Put your feelings aside and get to know us before you judge us!
Been to one of our Rallies yet??
To meet us, is to love us!

Party on!

Leon

[rexsk8er]

glad you got your bike running good salty.


As for mine, I vacume tested the TCI, and after fiddling with my vac pump finally got a good reading and it didnt loose any vacuum.

The next step was swap in a dyna, but low and behold its for a kawasaki vulcan. bAHHHH

so, after some more digging i found an old ass vance and hines powerpak. woop! open the cover and it says (86-93) well not so fast there charlie brown, after re-doing the switches to get it how i think it should be, i plug it in and nothing!! no fire @ all.    i suppose it could be that my bikes an 85 but i thought they were the same pinout between years.

Soooo, considering all this, I decide to do some more testing on the I/M's, The first test was at idle, and a very low idle at that. Well after spraying a shitload of carb cleaner with the idle turned up to 2k I got a drop in rpms.

I'm now convinced its still leaking air. Next step is to pull the carbs off, and test the choke circuit, buy some OEM hoseclamps and if all else fails new carb holders.

[saltyfj1200rider]

You may only need new boot o,rings. I ordered a carbtune II and a colortune today to do the final adjustments. I stumbled across the colortune,never heard of it. I am curios to see how well it works. I have my FJ and my friends CB900F to tune.

[rexsk8er]

Color Tune is a wonderful tool. I've used it to dial in many bikes. Pretty easy to use too, and you get to see inside the combustion chamber 

And, I have of course replaced the o-rings. I've had the carbs off a couple times. It'll be right I'd just like some OEM hose clamps the ones on there now are crap. I think thats why its leaking but I'm going to pull the carbs off again and fix some body work problems, Carbs are comeing back off to vac test internal choke pass and a few other possible leaks.