78 XS 400 2E won't start!

[Ed Dunham]

I am working on my son-in-law's 78 XS 400 2E (kickstart only). It has not run in a long time and a lot of folks have had their hands in it. I am a long time bike guy, mostly retired, and son-in-law and daughter have their hands full with a new house, a toddler and a baby on the way. So I offered to get it going. Most of my experience is with old British and Italian bikes. The carbs were off, somebody had installed an electronic ignition, lots of bits were missing, the front brake was locked up, and the clutch adjuster was frozen. I cleaned the carbs. One of the pilot jet screws had broken the tip off and I had to drill it out with a finger drill. The diaphragms are good. I set the pilot jet screws at 2 1/2 turns out per comments on this forum. The wiring for the electronic ignition was a mess. I straightened that out and reset the ignition to the starting point suggested by the system's directions. I have spark on both cylinders. I unfroze the clutch adjuster under the sprocket cover and adjusted the clutch. The kick starter didn't catch until about halfway through its travel resulting in only about 90 degrees of kick action on the first kick. it would then slip and only give about 30 degrees of kick action. I replaced the clip on the kick starter shaft and repositioned the shaft. This gave me about 110 degrees of rotation. Less than what I am used to on other bikes, but better. I tested cold compression in both cylinders. 118 in the left and 125 in the right. When I kick it, I get nothing. No pops, nothing. Any suggestions?
Ed

 

[CaptChrome]

Hi Ed, welcome to the forum. A nice thing you are doing for the family, I hope you are having a bit of fun at the very least.

My two cents on this issue - based on what you have done so far, the issue sounds like either fuel or spark timing related, so I would do the brute-force method of spraying a bit of starting fluid directly in both carb throats immediately followed by some vigorous kicking of the starter lever. If the engine doesn't fire, or if there are serious backfires through the carbs, then at least you know you need to look deeper at the ingition and timing. Otherwise it is back to the petcock and carbs.

 

[Ed Dunham]

Hi Ed, welcome to the forum. A nice thing you are doing for the family, I hope you are having a bit of fun at the very least.

My two cents on this issue - based on what you have done so far, the issue sounds like either fuel or spark timing related, so I would do the brute-force method of spraying a bit of starting fluid directly in both carb throats immediately followed by some vigorous kicking of the starter lever. If the engine doesn't fire, or if there are serious backfires through the carbs, then at least you know you need to look deeper at the ingition and timing. Otherwise it is back to the petcock and carbs.

Today, I hooked up my remote tank to give better access to the carb adjustments. After changing the pilot adjustment to1 1/2 turns out and giving it a few boots, I got it to burble for a few revolutions. This repeated itself once and then nothing. I checked the plugs and they smelled of gas. I then decided to check the battery. It is a new battery, that was fully charged when I started the project. Now it measured 12.07 volts with the ignition off, 11.47 volts, with the ignition on. My experience with electronic ignitions in general is that they won't work when the voltage is that low, so out came the battery and it went on the charger. Will try again tomorrow. Unfortunately, I have no meniscus left in my kicking leg, so I only get a few kicks in before I have to stop and there is no way I can run and bump it. Crossing my fingers and hoping it starts with the charged battery. I really wish that the last folks in here had not taken the points out and binned them. My experience is that they are far less sensitive.

 

[Ed Dunham]

Success! Burbled a couple of times with the recharged battery, but still didn't start. Sat down and looked at the electronic ignition. It's one of the ones that Mike's sells. The directions say to start off with the mark on the stator plate at 12:00. Looking at the plate, it looked like the mark was closer to 12:05 or 12:10. Moved it to 12:00 and it started on the next kick. It revs up and down. Doesn't idle, but starts right up again. Tomorrow I will start it and 1) strobe time it; 2) balance the carbs; and, 3) adjust the pilot jets and idle. For now, however, I will have a celebratory cocktail!

 

[CaptChrome]

it started on the next kick. It revs up and down. Doesn't idle, but starts right up again. Tomorrow I will start it and 1) strobe time it; 2) balance the carbs; and, 3) adjust the pilot jets and idle. For now, however, I will have a celebratory cocktail!

Congrats!

 

[Ed Dunham]

Well I spoke to soon! When I tried strobing it, I was mystified at first as to why I couldn't get anywhere near the timing marks, until I realized that there was cold air coming out of the right hand cylinder. It was only running on the left! I found that the plug cap was bad. No continuity through it. Replaced the cap and I got continuity. It had spark. Repositioned the stator and began kicking. Nothing. Tried it in a number of positions. Nothing. Tested the battery again. It was weak, although not as weak as before. Put it on the charger for a couple of hours. Had spark, but it was weak. Didn't start. Put the battery back on the charger overnight and gave my knee a rest. The next day, with the battery nicely charged, I tested for spark. It was blue and present for both sides, but fainter than before. The Mike's XS electronic ignition directions caution against running the bike without a spark plug in the cap grounding against the case. It strikes me that running it with a bad plug cap would have precisely the same effect, so I am wondering if I have damaged the unit. I just bought a used points set up off Ebay. If it doesn't start off the electronic ignition tomorrow, the points are going back in! Which brings up an interesting question. The condenser for the points is still in place and wired into the harness. I can't think of any reason why it would be needed with the electronic ignition and several reasons why leaving it attached to the harness might be a bad idea. I don't see anything in the directions about removing it. What is the group consensus?

 

[Ed Dunham]

I bought a points plate, points cam, XS 650 condensers off eBay, and connectors off Mike's XS. Installed everything, timed it and it wouldn't start until I realized I hadn't timed it on the compression stroke! Lousy mechanic! Flipped the points cam and it started on the first kick. Continued to also. My carb gauges indicate that the carbs are pretty well synchronized. Played with the pilot screws a bit. Some difference, but not as much as I would think. Because I had to drill out the one, I suspect that the little holes into the carb mouths are not exactly the same between the two carburetors. I have a Colortune somewhere that I will dig out and see if I can use to adjust the pilots to read the same. I also have a pretty good oil leak that only leaked while it was running that I will need to fix. But it appears that I am on the home stretch!