80G Trouble Starting but Runs Great

[totaldrk62]

Hello all! I have a 1980 XS1100G that I've been restoring for the past year or so. I've rebuilt the carbs, replaced the air/oil filter and all oils, repaired a few electrical demons (****ty grounds, headlight diode, broken ignition wire), repaired the advance wires (two were broke), replaced the fuse panel with a ATO style, new iridium plugs, AGM battery, cleaned/replaced brake pads, rebuilt the rear master cylinder (bastard), synched the carbs, removed all the rust from the tank (electrolysis) and resealed it with POR15 and replaced tires.

I don't think I missed anything there. Anywho, this bitch does not like to start cold. I have to crank it and crank it before I can finally get it to idle. I would say sometimes it can take up to 5 minutes of my cranking before it finally wants to idle. I'm assuming it isn't until it warms a bit before it wants to run. Once it is running and warmed up it runs fantastically. I've had it well over 100MPH and it runs fantastically. However the next morning it is just a bitch to start.

The choke seems to actually prevent it from starting both at half and full choke. To start it I have to give it a little throttle, and a little more and a little more before it finally starts a really slow idle. Sometimes it will die and I have to hit the starter again before it finally warms up. Once it is warm it idles normally. The carb boots are a little cracked on the outside but I've sprayed around them with starter fluid and the RPMs don't move. Stock air filters.

It feels like it isn't getting enough fuel when I'm trying to start it but the choke doesn't seem to be doing anything. I know the choke works because once it's running I can pull the choke lever and it will bog down (because it's flooding). I'm really at a loss. I've set the idle mixture screws to stock. They aren't broken inside the body because I can move each individually and the engine reacts to the adjustment.

What am I missing here guys? Could the coils be going? I get spark on all 4 and the exhaust on each is warm. I've got a XS650 I've restored which I like because it starts on one kick...so I know I'm not a complete idiot.

Thanks for looking.

[motoman]

Hello all! I have a 1980 XS1100G that I've been restoring for the past year or so. I've rebuilt the carbs, replaced the air/oil filter and all oils, repaired a few electrical demons (****ty grounds, headlight diode, broken ignition wire), repaired the advance wires (two were broke), replaced the fuse panel with a ATO style, new iridium plugs, AGM battery, cleaned/replaced brake pads, rebuilt the rear master cylinder (bastard), synched the carbs, removed all the rust from the tank (electrolysis) and resealed it with POR15 and replaced tires.

I don't think I missed anything there. Anywho, this bitch does not like to start cold. I have to crank it and crank it before I can finally get it to idle. I would say sometimes it can take up to 5 minutes of my cranking before it finally wants to idle. I'm assuming it isn't until it warms a bit before it wants to run. Once it is running and warmed up it runs fantastically. I've had it well over 100MPH and it runs fantastically. However the next morning it is just a bitch to start.

The choke seems to actually prevent it from starting both at half and full choke. To start it I have to give it a little throttle, and a little more and a little more before it finally starts a really slow idle. Sometimes it will die and I have to hit the starter again before it finally warms up. Once it is warm it idles normally. The carb boots are a little cracked on the outside but I've sprayed around them with starter fluid and the RPMs don't move. Stock air filters.

It feels like it isn't getting enough fuel when I'm trying to start it but the choke doesn't seem to be doing anything. I know the choke works because once it's running I can pull the choke lever and it will bog down (because it's flooding). I'm really at a loss. I've set the idle mixture screws to stock. They aren't broken inside the body because I can move each individually and the engine reacts to the adjustment.

What am I missing here guys? Could the coils be going? I get spark on all 4 and the exhaust on each is warm. I've got a XS650 I've restored which I like because it starts on one kick...so I know I'm not a complete idiot.

Thanks for looking.

The fuel/float leves are set too low. 23mm for the original carbs with the recessed idle mix screws.

[tcoop]

the 80LG that I have (Ok it's my daughters) I had the same problem.

Float height and idle mixture need to be set correctly. (Not to mention the carbs need to be really clean)

Set the idle speed to about 800 rpms (after the bike is warm) adjust the idle mixture (one at a time) until you get max rpm. reset to 800 then move to the next idle mixture. after setting all four. sync your cabs, rinse and repeat. (someone else may be able to describe the process better than I)

Float height is set depending on plastic floats or brass ones (newer carbs or older ones). Set them too high (height of float when measuring upside down) you starve you engine of fuel especially at idle, to low and you run to rich (and possibly flood you transmission with gas) . I do not recall what height they should be at its in the manual. (Motoman has a better memory than I )

[totaldrk62]

The fuel/float leves are set too low. 23mm for the original carbs with the recessed idle mix screws.

I did adjust the floats to 23mm when I rebuilt using a caliper and yeah they are the plastic ones. The bike had been sitting since 96 and they were gunked so I knew I'd had to reset them. They were actually bent a bit from the weight of the floats themselves to I had to bend them back into place...but I know set them at 23mm. I used this guide when rebuilding them.

[totaldrk62]

the 80LG that I have (Ok it's my daughters) I had the same problem.

Float height and idle mixture need to be set correctly. (Not to mention the carbs need to be really clean)

Set the idle speed to about 800 rpms (after the bike is warm) adjust the idle mixture (one at a time) until you get max rpm. reset to 800 then move to the next idle mixture. after setting all four. sync your cabs, rinse and repeat. (someone else may be able to describe the process better than I)

Float height is set depending on plastic floats or brass ones (newer carbs or older ones). Set them too high (height of float when measuring upside down) you starve you engine of fuel especially at idle, to low and you run to rich (and possibly flood you transmission with gas) . I do not recall what height they should be at its in the manual. (Motoman has a better memory than I )

What do you mean when you say max RPM? You mean adjust it out until it stumbles (floods) then give it a quarter turn back in? That's how I've always set them.

[ViperRon]

Check the resistance on the wires and caps going to the plugs if the resistance gets to high you get poor spark I have had that before. Bike will run fine once running but hard to start till it gets warm. Condition also is worst after it rains or you wash the bike. If bike has any trash in carb can cause a lean mixture and will make hard starting and tuning. If its a little rich starts easier and runs cooler.

[TopCatGr58]

Hey Total,

A few things stick out to me that I have to ask about. First, when you cleaned the carbs...did you soak them in caustic carb dip? That stuff will damage the butterfly shaft seals and give you a bad vac. leak that could prevent good vacuum from being able to siphon the fuel properly out of the float bowls.

Secondly, the float bowls have the choke/starter jets that are pressed into the bottom, did you spray carb cleaner into that HOLE in the edge of the bowl and ensure that fuel sprayed out of the JET in the bottom of the bowl. With the carbs being all gunked up, those jets clog easily, and if NOT cleared, then the enrichener/choke can NOT provide the required extra fuel needed for starting. Sometimes it takes using a very small strand of wire poked into that jet with repeated blasts of carb cleaner spray to get them open!

Next, AGM battery, but what are it's CCA rating? Put a voltmeter across the battery and monitor the voltage while cranking...if it drops to ~10.5 V, then even though the battery can CRANK the starter motor, the ignition system doesn't have enough juice/voltage to make it function properly, and you won't get any FIRE to start with!

T.C.

[totaldrk62]

Check the resistance on the wires and caps going to the plugs if the resistance gets to high you get poor spark I have had that before. Bike will run fine once running but hard to start till it gets warm. Condition also is worst after it rains or you wash the bike. If bike has any trash in carb can cause a lean mixture and will make hard starting and tuning. If its a little rich starts easier and runs cooler.

What resistance should I be getting?

[cajun31]

Testing procedure From the manual

The ignition coil is a form of transformer which develops the high voltage required to jump the spark plug gap. The only maintenance required is that of keeping the electrical connec- tions clean and tight, and occasionally checking to see that the coil is mounted securely. If coil condition is doubtful, there are several checks which may be made. Disconnect coil wires before testing. 1. Measure the coil primary resistance, using an ohmmeter, between both coil primary ter- minals (Figure 26). Resistance should measure approximately 1.5 ohms ± 10% at 68F (20 °C).
2. Measure the coil secondary resistance be- tween both primary leads. Resistance should be approximately 15k ohm ± lO% at 68 °F (20 °C).
3. Replace any coil if the spark plug lead ex- hibits visible damage and/or if they do not meet the preceding test specifications.

By the way you can get the manual here http://www.ringler.us/family/mybike.html.

[totaldrk62]

Hey Total,

A few things stick out to me that I have to ask about. First, when you cleaned the carbs...did you soak them in caustic carb dip? That stuff will damage the butterfly shaft seals and give you a bad vac. leak that could prevent good vacuum from being able to siphon the fuel properly out of the float bowls.

Secondly, the float bowls have the choke/starter jets that are pressed into the bottom, did you spray carb cleaner into that HOLE in the edge of the bowl and ensure that fuel sprayed out of the JET in the bottom of the bowl. With the carbs being all gunked up, those jets clog easily, and if NOT cleared, then the enrichener/choke can NOT provide the required extra fuel needed for starting. Sometimes it takes using a very small strand of wire poked into that jet with repeated blasts of carb cleaner spray to get them open!

Next, AGM battery, but what are it's CCA rating? Put a voltmeter across the battery and monitor the voltage while cranking...if it drops to ~10.5 V, then even though the battery can CRANK the starter motor, the ignition system doesn't have enough juice/voltage to make it function properly, and you won't get any FIRE to start with!

T.C.

TC, thanks for the help.

I did soak them in a carb dip pretty hard so it absolutely could be the case that I damaged the butterfly seals. ****. Looks like I'll need to order those and replace them. The process

I did clean the choke holes with some guitar string. I've heard piano wire works too but I've never tried it. I did have flow when I sprayed through them but I may as well do another full cleaning if I'm replacing the butterfly seals.

The AGM battery I picked up is 340CCA. I've checked voltage while starting and I've always been above 11.5v. This issue has a occurred on a completely charged battery so I don't believe the battery is an issue but I'll have the seat off so I'll take a look at that too.

This will be the third time I've had the carbs off, so I'd imagine this is the one that will do it. Honestly compared to my XS650 this bike has been a breeze to restore.

[totaldrk62]

Check the resistance on the wires and caps going to the plugs if the resistance gets to high you get poor spark I have had that before. Bike will run fine once running but hard to start till it gets warm. Condition also is worst after it rains or you wash the bike. If bike has any trash in carb can cause a lean mixture and will make hard starting and tuning. If its a little rich starts easier and runs cooler.

Actually now that you mention it the bike does run like **** after I wash it. Typically has to warm up again before it will run right. I will have to check my coils along with another good carb cleaning.

[TopCatGr58]

Before you take the carbs off, you can check for vacuum leaks around the butterfly shaft seals by having it running and then squirt some carb cleaner, or starting fluid, or even hold an UNLIT long tipped butane lighter against it while opening the lighter....and see/hear if you can detect any changes in rpm, up or down. If any changes while spraying, then yep, a leak, if not, then you may not have a leak afterall??

The butterfly shaft seals aren't that hard to change, but the 2 screws holding the butterfly valves on the throttle rods are PEENED over, you'll need to grind them a bit before unscrewing them, and then you'll need to repeen them, or use some red locktite to secure them back in/on, don't want them coming loose and getting sucked into the engine! There's more info that's been posted about taking them off and on, getting them positioned in the same position and same carb they came off of, etc.!

BTW, the ignition coil secondary resistances are to be measured with the plug caps OFF...the 15K Ohm value is WITHOUT the caps on, the caps themselves should be ~5k, if much higher, may have internal corrosion of the resistor/contacts, can attempt to disassemble and clean, or may need to replace.

T.C.

[totaldrk62]

Before you take the carbs off, you can check for vacuum leaks around the butterfly shaft seals by having it running and then squirt some carb cleaner, or starting fluid, or even hold an UNLIT long tipped butane lighter against it while opening the lighter....and see/hear if you can detect any changes in rpm, up or down. If any changes while spraying, then yep, a leak, if not, then you may not have a leak afterall??

Can I do this through the air filter box or should I remove. I suppose if I do end up having a leak I am going to have to take it off anyway to spray each individual carb.

The butterfly shaft seals aren't that hard to change, but the 2 screws holding the butterfly valves on the throttle rods are PEENED over, you'll need to grind them a bit before unscrewing them, and then you'll need to repeen them, or use some red locktite to secure them back in/on, don't want them coming loose and getting sucked into the engine! There's more info that's been posted about taking them off and on, getting them positioned in the same position and same carb they came off of, etc.!

Good to know. I will have to hunt this info up if I need it.

BTW, the ignition coil secondary resistances are to be measured with the plug caps OFF...the 15K Ohm value is WITHOUT the caps on, the caps themselves should be ~5k, if much higher, may have internal corrosion of the resistor/contacts, can attempt to disassemble and clean, or may need to replace.

T.C.

I assume just the caps and not the entire wire? Thanks again for all your help.

[ViperRon]

The issues I had was with the NKG resister caps for the plugs. Two places become a problem first is the plug caps screw into the cable to make connection with the wire. Over time corrosion can build up and what happens is when moisture is there you have poor conductivity and when it gets hot and dry it will act normal. Second some caps will come apart and you can see the issue. The end of the cap will have a slotted screw in the end where the cap connects to the plug. When you open this you find a resister and a spring. This is a sealed area but over time heating and cooling moisture can build up and increase resistance to where there is little or no spark. Then when it finally either arc's enough or warms up it fires a few times and burns the corrosion enough you get a decent connection. If the wire end looks in any way corroded then you can clip of 1/4 inch of wire and make a good connection. If you have corrosion you can use a tarnish remover product like TARNEX and soak and wipe off the spring, resister, and screw. The inside can be cleaned with a Qtip but a dremel with a wire brush polishes better. When putting it back together its best to put a little ignition grease on the connection points. Measure the cps and if you have more than 5K OHM's the cap is bad and needs to be replaced Measure the resistance as Cajun31 said but with caps on if they are resister caps you should have less then 20K OHMS if not there is a problem. If they are not resister caps very minimal resistance.

My experience with deep soaking carbs is this. If the seals have gotten hard then the carb soak may possibly eat them up and cause vacuum leaks. If the seals are still flexible like mine have been then carb cleaner soak probably is ok. Never substitute cleaners like mineral sprits paint thinner or paint removers as this will eventually eat up the seals and they will get hard or crack. As TC said Many times seals are damaged by removing the butterfly shafts. The issue is that when the screws are put into the butterfly shafts and peened they deform the shaft at the end and if the screws and butterfly's are removed and you do not polish the screw holes with good lube on shaft and pull the shafts you can easily scratch groves in the seals. I have soaked my carbs for a day many times and no issue yet but my seals are still flexible so if they are hard or you are not careful you can easily damage them. The other issue is what has the previous owner done to them. You just may clean the dirt off that sealed them.

[jpilk99]

Tangent. How's your battery?

This may be way out of left field, but, when I read your initial post - it reminded me of my bike ('81 Midnight Special). My battery was pretty weak and I had a hard time starting and getting it to warm up (obviously, the battery is basically out of the loop once you've started). Now, with a new/strong battery, everything seems to come on line - run better - more quickly. Just a thought.

My experience, as echoed here, is that if those carbs and everything involved with the provision of fuel & air is not perfect ...you're bumming.

Good luck!

Jay