78 standard takes too long to warm up between rides

[SIZZSAM]

Hello everyone, I have a problem with my 78 standard. I cleaned the carbs, synched and color tuned. I checked the timing and adjusted the valves. It seems to take extra long to warm up. Once warm it runs great, nice and smooth but if I stop for a short while it is cold and takes a long time to warm back up. It also seems to be getting poor mileage since it's sitting a lot warming up. Any suggestions? I have another standard that once warmed up is good to go. Thanks for your help. Sam

[SIZZSAM]

P.s.

I forgot a few details that might help analyze the problem. When I use the enricher circuit it doesn't seem to work. Usually the rpms would gradually rise and I would put it in the second position and it would run for a while and then the rpms would rise up to around 4000 and I would push it in all the way. I cleaned the enrichner circuit and pilot jets very thoroughly. Also at first it sounds like a two cylinder bike until it is warmed up and all four cylinders are hitting. I was thinking maybe it was the coils but they would misfire all the time. It seems more like fuel. I may have to go through the carbs again and maybe get a fuel filter. Any suggestions would be appreciated. Sam

[TopCatGr58]

Hey Sam,

You say you have 2 bikes. A quicker easier ruleout of the carbs/fuel would be to swap the carbs from the known good performing bike onto the problematic one. If it still behaves badly, then you can rule out the carbs and explore more of the ignition system. If it behaves well, then it would seem that the carbs are messed up because other good carbs solved the problem.

You also state it seems like it's firing on 2 cylinders at first. Take some water in a little spritzer and apply it to the pipes and see if any of them sizzle or not during the warmup. If you then find a PAIR ie. the outer 2 or the inner 2 not behaving/sizzling, that would again point you more towards ignition, PU coils, ignition coils, etc.!

T.C.

[SIZZSAM]

Thanks Top Cat, I'll check that out tomorrow to see if I can narrow it down to ignition or fuel. Yes, while it's warming up it sounds like a twin and then you can tell when the other two start hitting and then it's a powerful inline four. I rebuilt the carbs and when I put them back on it wouldn't start. I finally checked the coils and they didn't read well on the secondary windings so I replaced them with two that I had purchased on ebay a while back. It started and ran with them but not that good. I also put new plugs in and set them at .027. There is an error between the user's manual and the service manual in the spark plug clearance. I noticed on the forum most said they set theirs at .035. I think I increased the gap and it didn't seem to run as well. What is your thought on that? It seems my starter circuit isn't performing. I could have some trash in the carbs so I'll take them off and check them out tomorrow. Thanks for all the help. Sam

[DGXSER]

I would gap them at .032-.035. That alone can drastically effect millage. Took a road trip with a fellow XSive some time ago and he got 15 MPG or so on the way out due to mis gapping his plugs (on purpose). He corrected the gap and got double that millage.

I agree with TC, let it run while on 2 cyliders a minute or three, then see which pipes are hottest. That should show you which 2 are not firing. Also, did you check your fuel lines are not kinked? Do you have good vacuum line to the carb, is it on the barb completely? Just thinking if your on limited fuel flow to a pair of carbs. But first is the water test to isolate fuel or electrickery.

[SIZZSAM]

Thank you, I will change the gaps tomorrow. For some reason I was thinking that the shorter the gap the less work the coils had to do and would last longer. These are used coils that I got on ebay but they read the right resistance in both primary and secondary. If the coils were misbehaving I would think it wouldn't run that smooth once it's warmed up. It doesn't skip a beat and will roll on like it's supposed to. I haven't checked it at real high mph though. I just remembered I have one of those hands free thermometers from Harbor Freight that I can check the pipes with. I have read a lot of threads about the pick up wires that go to the coils having problems so I'll check those out and make sure they are o.k. Thank you again for your help. Sam

[DiverRay]

If they have a higher reading, they MAY be "newer" coils. These are designed to run WITHOUT A BALLAST RESISTOR! That may be part of your problem. Check the readings against the '81 coil specs.

[SIZZSAM]

Thanks Ray, these are old coils that are identical to the oem that was on the bike. I do have a ballast resistor and it reads the correct resistance. I'm thinking my vacuum advance hose might be a problem. It was cracked where it went into number two carburetor and I cut it back a little. I will check it out again and replace it today. I'll use some starter fluid and check for vacuum leaks. Once it warms up when you roll on the throttle it will come right back down with no hesitation and I think that means no vacuum leak. On the other hand when it is warming up the throttle response hesitates coming back down. I'm going down to the basement to start working on it and see what happens. Thank you again Ray for your help. Sam

[MPittma100]

Too Long

The enrichment circuit is on each of the 4 carbs. Since there is no response to it, I would say that your problem is elsewhere.

I had one incidence where the bike took too long to warm up like yours and found a float hanging up on number 1 carburetor. I removed the drain plug to find no fuel. I was able to take the bowl off without removing carbs. I replaced the float - Problem solved. This was right after a carb rebuild. Number one pipe was not hot.

MP

[SIZZSAM]

Thanks MP, I was able to take a look at the bike this morning when it was cold. I used one of those thermometers with the red lazer to aim and checked out the exhaust headers while the bike warmed up. Number 1 and 4 were doing fine but 2 and 3 were not heating up at all for the longest time. So it looks like something to do with the coils or pu lead going to the 2 and 3 coil. I had to quit for the day as something else came up but will check out the coil and pu lead later. I revved the throttle extra during warming and took off and before long it was hitting on all four. It looks like if it was the 2 and 3 coil it would act up all the time. I still haven't reset the gap on the plugs as they are still at .027. I was going to change them to .032 and see if it made a difference in the mpg. By the way, I have a 79 SF also and live in Douglasville. Drop me an email sometime and maybe we could compare notes on the XS S. Sam

[bikerphil]

I would check the PU coil wires, sure sounds like the problem...

http://www.xs11.com/xs11-info/tech-t...pictorial.html

[SIZZSAM]

Thank you Phil for the pictures. I've done a lot of soldering and wire repair on my bikes but I haven't had to do the pu wires yet. I'll check those with the engine running. It sure sounds like it could be the trouble. I think I have seen numerous posts about it over the years. That heat shrink is pretty neat stuff. I've been getting mine at harbor freight for not much money and it sure dresses up a splice. Remember all the electrical tape knots. I'll let you know if that was the problem. Thank you again. Sam

[DGXSER]

Yep, with 2 and 3 being the culprits, it would lend itself to electrical issues. Most likely and easiest to diagnose would be the pickup coils.

I have yet to have to do this repair. However, if it is the issue with your bike, I would pull the coils off the bike, and go back in the harness to the splice point form the factory and replace the wires all the way back to that splice. Just keeps from having another break in another area of the wire. Also moves the splice out of the timing cover into a sheathed area.

[bikerphil]

If the wires pass the 'stretch' test, I'd leave them alone. JmHo

[DGXSER]

Yes, what I meant to imply is if the wires turn out to be the issue.