82 xj1100 starting problem

[justyn.smith]

no fuel

If there's no fuel getting into the cylinder you need to ensure that the fuel is getting to the carbs, try setting your petcock(s) to 'prime' and opening your float bowl drain screws. if you don't get fuel leaking out then likely your fuel lines are kinked or filters blocked etc.

If there's fuel getting into the carbs then it looks like you'll have to remove the carbs and do the old clean-clean-clean (refer to the triple clean section in tech tips).

Good luck.... oh one more thing, if you're getting fuel, before pulling your carbs, make sure your vacuum hoses (if any) are in good nick. my bike developed problems when the vacuum hose from carb2 lost it's seal, 2 hose clamps fixed all my probs.

[TopCatGr58]

Hey there SJThaler,

First, like Jerry said, check to make sure that when you pull on the choke lever, that the choke/fuel enrichment lever on the carbs and the rod that slides to pull/push the enrichment plunger on all carbs is actually moving!! IF it's not moving, then it could be the cable.

Secondly, the fuel diaphragm/Octopus could be at fault, and that's why Justyn mentioned putting the petcocks on PRIME, that sends fuel directly to the carbs, bypassing the Octy. If you're getting fuel to the carbs, then you can concentrate on the choke circuit and actuator mechanisms. You can also check the octy by applying suction to the vacuum line, and it should then allow fuel to flow thru the main circuit to the carbs.

With even compressions, sounds like your valve clearance isn't too tight, if it was, then you would have much lower or nonexistent comp levels!!

Happy trouble shooting, come back with any more questions and results of your efforts for more ideas, if you need any!!
T.C.

[ratbyk]

Choke Circuit

Start by following Jerry's suggestion of "helping" the choke/fuel enrichment come into play. Find were the choke cable connects into the # 4 carburetor. As you pull the choke off and on "observe" what is happening. Make sure any choke cable movement is matched with movement of the "rail" that connects all of the carbs together and activates the "fuel enrichment" As Jerry suggests, help this rail move even more by pushing on it with your thumb. Try and increase the amount of travel which will provide more fuel.
Cold engines need lots of fuel to fire and start. Cold fuel/carbs/intake manifold/cylinder ports/valves/combustion chambers do not induce raw gasoline to vaporize. It requires heat or a lot of extra fuel. You need a few molecules of gasoline/hydrocarbons between the gap in the spark plugs to ignite the charge. Once started the increased velocity of the fuel charge coming helps a lot but you will still need a bit of choke for the first few moments/minutes dependent on many factors.
Possibly a little lubricant WD40/light oil on the rail to free it up and allow easier activation would also help.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

[piet]

To check if there is fuel coming from the tank simply turn the little screwsplugs out at the bottom of each carb,if there is coming any fuel out of there it must be possible to start the engine with it.
Don't use the trottle at the moment you start up only the choke
i mentioned the intake hose under your seat that brings the air in your airbox,i hope it is almost the same as the XS type

[John]

Originally posted by sjthaler
I cranked and cranked, and then checked the spark plugs. They were not wet. Where do I start on the fuel delivery?

You said that you had the bowls off. When you had them in your hand, did you check the small 'wells' in the edge of the bowl to make sure that it and it's passageway to the bowl were clear? That is where the choke or enrichment system gets it's fuel supply. When the bowls were off, did you notice a small brass tube protruding from the base of the carb? That is the pick up tube for the enrichener. You may have an obstruction there, and it is a small port, so it would plug easily. Another place to check for fuel obstruction is above the screens that are attached to the top of the float seat. You'd be surprised at what I found there when I went through the carbs that came from my 78. It had been sitting for God knows how long, and some insect had gotten in there and made a nest and then died.
Try using a little starting fluid. Remove the air filter access from the airbox and spray some ether in there, and see if it at least tries to fire off.
Some before me mentioned using the prime function on the petcocks. That will by pass the octopus and direct fuel straight to the carbs. That way if the ocopus is malfunctoning, fuel will still flow to the carbs.

[sjthaler]

Well, I pulled the carbs, gave them a very good cleaning and reinstalled. I did not notioce anything unusual. With a little coaching with some starting fluid, the bike started. It idled well, and restarted quickly after I shut it down. The next day I went out and tried to start it again, and it would not start even with it fully choked. Back to square one. Question: How does the YICS system play into this?

I note that when I first try and start it, it pops for about 2 seconds, then won't start. I am still looking for suggestions before I go to a shop.

Steve

[Hobbit]

yics

The YICS system is just a passage that connects the intake runner from all of the cylinders together. Instead of each carb having vacuum pulling from only one cylinder which creates strong vacuum pulses, the intakes "share the vacuum from all of the cylinders. That's why you must block off the YICS passages in order to adjust each individual carb.
A few imported cars with multiply cargs use a similar system called a "balance tube".

[piet]

do that start trick again with that stuff and let the engine run for twenty minutes,and go for long ride on that bike on a highway to get a well warmed up machine and after coming home check the color of the bougies to see if the carbs need adjustment's

[sjthaler]

When the bike finally starts it runs well and the plugs look great. Soon as it sits overnite, it won't start the next day. For some reason it just does not seem to be getting gas through the choke. It sits and on first crank fires, but then it is like it is out of gas. May be I will try another carburator cleaning. Am I missing something?

[justyn.smith]

In spite of everything, how old is your battery? If it is losing charge overnight it might have enough crank but not enough spark, that woud explain why it 'pops' at first but then with the starter drawing current it doesn't give a good spark. FWIW

[sandman]

My Seca 750 did this exact thing. If it didnt fire in the first few cranks, you were done. It took a fast push start or ether to get it to fire. Then it ran fine. Would also start fine after it was warmed up.

Turned out to be a weak battery. Changed it and no problems after that.

[sjthaler]

I actually bought a new battery and they told me to charge it for 2 hours at 2 amp. They said no more than 2 hours. Is this correct or can I charge it for a longer time? It seems to have enough cranking power but maybe not!

[piet]

hoi,most chargers have a indicator that tell you when the battery is fullyloaded and ready for use,do you have one

[ratbyk]

New Battery

I would follow the battery manufacturers/sellers recommendations. If it has enough power to easily start the bike that is all you need to start with. Then take the bike out for a couple of hour ride at highway speeds. This will let the bikes charging system top it off at what will be normal charging/starting voltages for this particular bike.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"
92 ZX11 Temptress

[sjthaler]

Other than the battery, is there anything else that would cause a weak spark?