Muffinman, Bike won't idle below 3000 rpm

[Tommy]

Well Jeff, here I am again..While I had the carbs out of Bertha, I took the opportunity to do some preventative maintenance I had been putting off. I replace the leaking valve cover gaskets and I had found a coolant hose collapsed. Also, it was time for new antifreeze. Carb. cleaning was uneventful after the screws were finally removed. Reassembly went reasonabley well, however it took me a long time to get the control cables hooked back up. Anyway, all is back together and I cannot get the bike to idle below 2500 to 3000 rpm. Is this a TCI problem? The bike ran a little ragged for about 10 miles, number two cylinder was cutting in and out, running rich and then spark knocking . Then the engine seemed to run better. Up jumped the idle. I have backed off the idle screw again and again to 1000 rpm, yet the idle rpm jumps back up after a short ride. I can find no hoses off anywhere. Have you had this problem before? Any ideas...anyone

[muffinman]

Tommy it sounds like a vac leak.Check your carb boots to make sure that they are seated all the way.Also check the air filter box boots they may not be seated all the way.

Jeff

[Squeeze]

Hi,

 

how's your Throttle Grip feeling ? Does it snap back to Idle Position from fully twisted ? Or, like a Friend of has had, it's a bit harder to pull and won't move from this Position without a little help ?

[Tupperj]

Tommy,

 

How's your carb sync? When this happened on my XS1100, it turned out my carbs were way out of sync.

 

Good luck!

Paul

[Tommy]

Thanks for the input guys..The carbs felt really well seated when I pushed them in to the manifolds. I'll check in the morning and install my vac gaugesand check the sync as well.

[muffinman]

Tommy if you cant find the problem ride the scoot to the meet and eat this weekend and I will see if I can get it taken care of.

Cary to the outer banks is only 3 1/2 hours

Jeff

[Tommy]

After cleaning the carbs the sync. was waaaay off. I put the gauges on yesterday morning and I can now idle the engine. I rode from home down to Sanford, about 70 miles round trip and I was happy with the way the bike ran until I slowed for a stop light. Now the engine is only running on two or three cylinders. I power back up, and the engine is solid again. Can it be a coil, plug wire or caps??? I changed the plugs. Can I purchase wire and caps from my local auto parts store?? If I try to buy from my local dealer I have to wait for stuff to be ordered...he never has what I need in stock...And, am I hurting the engine running this way?? I'm so confused....LOL

[Jrichard]

tommy, CHECK your carb diaphrams!!! may B pinholes?------similair thing happened to me checked the carb dia. and they all had holes------------either replace or patch!--------

[Tommy]

No holes, leaks, or tears....I am sure that I am dealing with some kind of electrical problem. The carbs balanced fine...Thanks for the input.

[Squeeze]

Hi,

 

how comes that you think it's electrical ?

 

Of Course, if the Plugs and Wires are somehow old, they can fail any Minute, occasionaly the fail while one's working on the Bike, but most likely if you work on the Carbs, the Culprit will be the Carbs.

 

If you want to change the Wires, Caps and Plugs, you can buy all at the local Autoparts Store. Just make Sure that the Caps are 'R' Type, the Resistor keeps the Spark Noise off from Radio and CB. Yours and your Neighbors.

 

Did you turn all the Idle Mixture Screws 2.25 Turns out ?

 

If you think that Motors works fine above Idle, you won't hurt anything while riding.

[muffinman]

Tommy call me after 3 pm and before 2 am at 9196735095

Jeff

[BradT]

Now the engine is only running on two or three cylinders. I power back up, and the engine is solid again.

 

Are you sure it is running on all four after powering up. I had one cylinder not firing once before and at highway speeds it was hard to tell it was only running on three (except for horrible gas mileage).

 

Mine was a bad plug.

 

Brad

[Tommy]

I guess I don't know for sure,...gonna replace the wires and caps when they get here..I still think the carbs are ok, but Jeff said he'd check them anyway.Could be a question of cable adjustment.

[Gearhead]

Flaky ignition is more likely to fire at idle and miss under load, not vice-versa. First, as already asked, is your bike really running on all 4 when revved up? A top speed test may be in order as I've heard that will quickly expose a missing cylinder under load. If the miss is only at idle, that suggests to me a plugged pilot circuit in the carb.

 

Jeremy

[Tommy]

Got up early, bundled up and left for Manteo, Got as far as Gorman street in Raleigh and had to turn around and head back home. Bike running on 3 cylinders and I was afraid to be out on 64 E. No help out there. I replaced the plug caps westerday and new plug wire. Bike ran ok and I had to readjust the idle screw again. This morning in started fine but never hit on all four cylinders. I know its number 2 cylinder for sure. Did the water test on all exhaust pipes and number 2 was cold. I hate to tear into the carbs again, but I am running out of options. I have a new coil for number 2 but I need to check the TCI and make sure the coil is getting signal to fire....Ain't life grand??

[Thom]

my # 2 has been driving me nuts , for no reason i would lose it and than it would come back it even backfired a couple of time , i did everything i learned on this site but rebuild the the carbs , the #2 spark plug would sometimes be black . when i syn. my carbs. it syn.ed out good . any way to cut this short , i found a split under the clamp on the back side of the vac. hose going from #2 carb to the cruise control , i cut off a 1/2 in. got all 4 back ! i am putting all new vac. line on this week and hopefully that will allso fix my dropping cruise control ?

[GeorgeS]

Have you had the Two Plugs pulled out of the TCI ??

 

If not, consider dirty, or corroded connection from the 8 pin plug on the TCI, the wire that goes to the #2 cyl Ignition coil. ( the center 4 of the 8 pins, feed signal to the 4 ignition coils )

 

Also, on that wire there is a two wire pull apart plug, about 6 inches before it gets to the coil. The contacts of this plug ( they are yellow or orange colored ) might be makeing intermittant contact.

 

In view that you seem to be indicateing that the problem comes and goes, makes me think you might have an intermittant electrical contact.

 

Also: consider, that you may have gotten a " bad " new spark plug. this has happened to me, more then once.

 

Also: Carefully follow the 2 wire cable comeing from the #2 Ignition coil, untill it enters the wireing bundle. Slight possibility that one of the two wires may be pinched somplace, and intermittantly shorting to ground. ( this is a very long shot, but possible )

 

Also: find the wire cable that comes from the " Pick UP Coils " located behind the Alternator Rotor. ( a 5 wire cable ) runs to rear out of rotor case cover, under the rear tran cover, then up from rear engine, then located about under your left Knee as you sit on the bike is located a " White " disconnect plug.

 

------ Why? -- The signal to the TCI to fire each cyl, goes thru this plug. This plug is know to have been the cause of many Ignition fireing problems. Open up this plug, make sure all 5 of the pull apart connectors inside the plug are Clean, and makeing good electrical contact. Clean these with a good electrical contact cleaner.

 

Also, use electrical contact Cleaner on your Two Plugs that mate to the TCI !!!

 

---- Electrical contact Cleaner !! Use CRC Brand 2-26, comes in a blue labled spray can. Get it at Lowes, Home Depot, and most auto parts stores, OR a similiar product.

 

One more item, give your Ignition Switch, and your " Run-Stop" Switch, a bath with this stuff, blow out with compress air.

 

Also: Find your 40 Amp, Main Fuse, located just left of battery. Open it and check the Two small #1 phillips screws, make sure the fuse element is makeing good contact.

 

Also: Check your " ING " Fuse Holder, make sure it is makeing good contact. These Yamaha fuse holders are known for going south.

 

Many folks have replaced these Fuse Holder blocks, with better quality after market items. This is a highly reccomended Winter Project.

[Tommy]

ThomS, George, Muffinman, and Freebird. I can't tell how much this old man appreciates your input...You have given me a lot of things to try. I was afraid to go out to Manteo today because I am not a great mechanic and I didn't want to get stranded out on 64E. Not much out there. I am going to try to establish that there is no spark for sure. I'll put a plug in the new cap, light up the engine and see if I can see a spark when I touch the plug to the engine to ground. If no spark, I'll try to determine if the TCI is working. Then as suggested by Freebird I will try to do maintenance on the TCI. Then I guess I'll have to catch Jeff on a weekend a truck on out to Hertford to adjust the carb cables..This is turning into a real project...Thanks again for all your support.

[Tommy]

I made up a new spark plug wire with new cap for #2 cylinder. When I loosened the wire retainer on the coil the wire seemed to fall out of the coil.I install the new wire and a spark plug into the new cap and fired up the engine..Touched the plug to the horn bracket and wallaahh,...spark. Now I pulled the plug from #2 cylinder and it was totally black and wet, and would not fire. I installed a new plug and I think the bike is running on all cylinders. I will find out for sure tomorrow, going to take a little test ride and see what happens. Jeff, did you guys have fun in Manteo? Sorry I missed it.