85 FJ1100 running lean I think.

VaughanCustoms · May 20, 2013, 04:24:33 PM

The guy I bought the bike from did a rejet and rebuild on the carbs about a year ago but has sat for about the last 4 because he got a new job out of state and cant take it with him. I found that two carb diaphrams are bad and got some parts ordered to sort that out. I was curious to know if anyone has a layout of could take a picture for me of the different vacuum hoses so I can double check them all to make sure there are running to the correct places. I see all the hoses under the carbs but from what I understand they are like drain hoses of some kind correct? I looked at the spark plug wires and they are not in to bad of shape but not great. I looked them up and they are like $100 for a set? Are there any altenatives that would cost less or are they pretty specific and it is what it is? Before I tore the bike down and started re-lubeing, re greasing and cleaning everything I had to have full choke to start it and then feather the throttle to keep he running and it would have a faint popping out of the exhaust. Any ideas or you guys think its prob due to the bad diaphrams?

movenon · May 20, 2013, 09:11:07 PM

Quote from: VaughanCustoms on May 20, 2013, 04:24:33 PM
The guy I bought the bike from did a rejet and rebuild on the carbs about a year ago but has sat for about the last 4 because he got a new job out of state and cant take it with him. I found that two carb diaphrams are bad and got some parts ordered to sort that out. I was curious to know if anyone has a layout of could take a picture for me of the different vacuum hoses so I can double check them all to make sure there are running to the correct places. I see all the hoses under the carbs but from what I understand they are like drain hoses of some kind correct? I looked at the spark plug wires and they are not in to bad of shape but not great. I looked them up and they are like $100 for a set? Are there any altenatives that would cost less or are they pretty specific and it is what it is? Before I tore the bike down and started re-lubeing, re greasing and cleaning everything I had to have full choke to start it and then feather the throttle to keep he running and it would have a faint popping out of the exhaust. Any ideas or you guys think its prob due to the bad diaphrams?

Just put new wires on mine this morning. Go to NAPA and buy 5 feet of 7mm solid core wire. I removed the coils and unscrewed/plulled out the the wires (if stock they are bonded in a little, just work them loose). Do the same at the plug terminals. RPM sells new terminals if needed. I think they are about 28.00 for all 4 of them.
As per RPM post a while back. Camfor the wire a little (just take the edge off) with a knife that go's into the coils, lube them with some die electric and they slide right in. Do a search, "plug wires" Randy has written some information on doing the job. Anyhow, it is easy and 5 feet of solid core wire was around 6.00...
George

poker007 · May 20, 2013, 09:22:29 PM

Did you drain the old fuel,and replace with Chevron 91 octane? And i would check the battery it could be shot,When you start cold With full choke, i don't run my 85fj1100 maybe 10 sec max with full choke then slowly bring choke1/2 then 1/4 Then i take off .i hope i was off some help

you might try some Techron in your fuel too !

markG

VaughanCustoms · May 21, 2013, 07:02:11 AM

Well when I started it no the tank had not been drained yet. Probably a mistake on my part but I wanted to make sure she had something before I started tearing her down that way I could give it back to the PO. The battery is new and yes the gas is now drained and when I get the tank back on I will have a full tank of premium and some seafoam in there as well. I have looked the carbs over and they are very clean just the two bad diaphrams. I prob need to sync the carbs I am sure as well but dont have the tools to do so but from what I understand is it should at least run desent even with the carbs a little off? Thanks for all the support guys. I am working though it.

movenon · May 21, 2013, 09:15:01 AM

Quote from: VaughanCustoms on May 21, 2013, 07:02:11 AM
Well when I started it no the tank had not been drained yet. Probably a mistake on my part but I wanted to make sure she had something before I started tearing her down that way I could give it back to the PO. The battery is new and yes the gas is now drained and when I get the tank back on I will have a full tank of premium and some seafoam in there as well. I have looked the carbs over and they are very clean just the two bad diaphrams. I prob need to sync the carbs I am sure as well but dont have the tools to do so but from what I understand is it should at least run desent even with the carbs a little off? Thanks for all the support guys. I am working though it.

You can make a carb sync tool for 15 bucks.

The restictors in the line are from a Harbor Freight brake bleed kit. They are cheap to buy. And they are the key to it. Reduces the pulsing down to about zero.
Hose 1/4 (I think) from Home Depot
Clamps are TV coax clamps
Fluid two stroke oil
Fluid level not cridical, about what you see.
No need for numbers or marks on the board, you are just measuring the vacum balance between the carbs.
If you want you can make two of them so you can do all 4 carbs at the same time if you like but it is not needed. Two at a time per the service manual works.

While you are at it make an extension to your fuel line coming from your gas tank. A foot or two of fuel line hose and a lawn mower fuel filter to use as a splice... Most auto parts store have them, cheap.

Put a towel under your tank to prevent any chance of shorting the bottom of your tank against the battery.

Do carbs 1 & 2, then do carbs 3 & 4 then do carb 1 & 3 (to balance the banks together. I then adjust the idle/air fuel and idle RPM then go back to do another balance.

George

VaughanCustoms · May 21, 2013, 09:18:27 AM

Thats pretty sweet but how do you know exacly how much vacuum it has? Because arnt these carbs supposed to run on certain levels of vacuum?

movenon · May 21, 2013, 09:54:06 AM

Quote from: VaughanCustoms on May 21, 2013, 09:18:27 AM
Thats pretty sweet but how do you know exacly how much vacuum it has? Because arnt these carbs supposed to run on certain levels of vacuum?

You are just balancing one carb to another the amount of vacuum is unimportant for syncing. Don't over think it. One carb is going to have more or less vacuum than the other, you will adjust until both have the same vacuum. On to the next two then balance the left bank to the right bank. (you will see 3 balance screws).
There are some examples on You Tube of different carb balancing tools and "how to's". Take a look there also.
George

VaughanCustoms · May 21, 2013, 11:02:48 AM

Oh I see, thats pretty wild. I had no idea it was that simple. I will check some stuff out when I get home and when I get the bike back together I will get things going.

VaughanCustoms · May 23, 2013, 07:02:01 AM

Well I tryed to repair my diaphrams with the Plasti-dip and they are def working better but still not exactly how they should. I desided to put it most of the way back together and try to start her after looking through the carbs, cleaning them, and getting some action out of the diaphrams now enstead of just getting stuck completly. I went to start it last night and I got no love at all

I am not sure what to do, I have built two car motors before and have not been so upset and mind blown before lol. I am just curious to know is there something I have missed? Any ideas?

News:

85 FJ1100 running lean I think.