Day One of Many - New Resto project

[J_C]

Again, thank you to everyone who has helped me through the purchase of my bike and a myriad of other qustions, including Chef, Earl, and everyone else who provided advice. Today I made it out to the workshop and got a lot accomplished (I think)...

Though I'm not asking a specific question, any comments would help....

1980 GS1100L Will not idle without heavy choke. Will not rev above 4000rpm. Number two not firing.

Testing Charging system: Battery - New YUASA YTX14AHL-BS

Off - 12.8

Ign On - 12.34

Idle (1200 w/ choke) - 13.8

2500 - 13.25

4000 - 13.3

Testing Spark Gaps

#1 - .66

#2 - .67

#3 - .67

#4 - .67

Number 2 Spark plug (#2 cylinder doesn't fire) was wet when removed. See below:


All four plugs produced blue spark when grounded against fins.

Compression

#1 - 124 PSI

#2 - 130 PSI

#3 - 132 PSI

#4 - 137 PSI

After running compression, bike wouldn't start. Suspect flooded carbs. Gas in a puddle underneath bike. DOH! Also of note, the inside bits of the #1 plug wire came out when taking it off of the plug. I put all the pieces back in except some itty bity flat metal disc. I didnt know where it went, so I tossed it. Seems to produce fine spark though.

Next up I conquer my extreme fear of carbs by cleaning and rebuilding. (Its rebuilding when you replace the orings, right?)

[J_C]

OK I guess I did come up with some specific questions after my reading last night and this morning. A more careful read through all five parts of the stator papers made me worry a little bit about my charging system test results. Does anyone have any experience with numbers like these?

Also, we regards to compression testing, I have read that they are supposed to be within 10psi of each other... Is approx 13 psi ok? I don't have my clymer yet (in the mail) so I'm not sure about the ranges, though I've heard 120 - 160? Does being at the low end affect performance? I haven't performed a valve shim adjustment yet so that may help correct?


Thank you very much! Lovin' this GS!

[Jethro]

I'm not sure what your range is for compression, but my 1100E can have a 20-28psi difference I think. You should pour a little oil in the cyls to determine rings or valves.

Can you confirm that the vacumm line is installed correctly? Sounds as if you are getting way to much air, and through the vacumm port.

[jgordon]

OK I guess I did come up with some specific questions after my reading last night and this morning. A more careful read through all five parts of the stator papers made me worry a little bit about my charging system test results. Does anyone have any experience with numbers like these?

Also, we regards to compression testing, I have read that they are supposed to be within 10psi of each other... Is approx 13 psi ok? I don't have my clymer yet (in the mail) so I'm not sure about the ranges, though I've heard 120 - 160? Does being at the low end affect performance? I haven't performed a valve shim adjustment yet so that may help correct?


Thank you very much! Lovin' this GS!

Compression is not your problem I don't think. Its probably not your coil if only one is not firing as you would have two that would not fire. What has me a little concerned is that you say it was wet but not firing so its getting fuel. It would be nice to be able to see your plugs from the end and not the side. Here's what I would do......

Check valve lash
Change places with the plug thats not firing and see if the problem moves
Go through the carbs completely
Check your plug wires real close

[Doctor Shifty]

Is there any reason you are running 7 grade plugs instead of the normal 8?

[tmv]

Won't run without full choke, #2 not firing

JC, had any luck? I'm experiencing the exact same problem on my GS650. According to Clymer's, you can swap the ignition coils to see if the problem follows a coil. If not, you can check the signal generator unit and igniter unit. I haven't been able to pinpoint my problem yet, (lack of time), but I'm also having trouble locating parts, I'm really needing an air filter. Good luck!

[Guest]

D8ea

You are running with the wrong plug but this would not explain why you would not be firing on #2 cylinder. Switch #2 and #3 spark plug wires and see if the problem moves to #3. If if does most likely it is a bad wire or plug cap. Check the plug cap connection by twisting off the plug cap and cut the wire just enough to get some fresh wire and twist back on. (connection looks like a wood screw) Check the spark on that wire with the spark plug removed and see if you get a nice bright white spark. This is probably the reason you won't hold an idle. To fix these wires you have to cut the old one off and join the wires together.

[J_C]

Got off the phone tonight with chef, thanks for all your input!

No reason for the wrong plugs other than they were in the bike when I bought it. I'll replace them this week for sure.

TMV, since the #2 and #3 share the same coil, and the problem is only on the #2 cyl, I would anticipate neither the coil, sig gen, nor ignitor unit to be at fault. I will follow jgordon's and chef's advice of checking to see if the problem follows the plug or the plug wire.

Carbs are definetely next on my list of things to do (who knew a rebuild kit was so expensive :? )

Once I receive my clymer's (monday hopefully) I will check to see the process for checking vacuum line and port per Jethro's post.

Jgordon, what is valve lash? Is that a similar test to valve shim adjusting? I will look that up in my clymer's as well.

Will also do the oil /compression test again once I receive my clymers with specs, so I know what to look for. I'm hoping its rings, right?


Thanks guys. When I was trying to pick a make.model for a project bike a lot of it was dictated by the online support I could hope to receive. Y'all are the best!

[jgordon]

Jgordon, what is valve lash? Is that a similar test to valve shim adjusting? I will look that up in my clymer's as well.

Will also do the oil /compression test again once I receive my clymers with specs, so I know what to look for. I'm hoping its rings, right?

Just set the valve adjustment to .004 on both the intake and exhaust while the motor is completely cold. You check it below each valve adjuster and not the cam follower.

[J_C]

Excellent, thanks!

[J_C]

Update on the #2 cylinder... put in the new plugs and swapped the wires. The problem did not follow from #2 to #3. In fact, once I had removed the new plug after running for two minutes, it didn't smell of fuel nor was it wet or anything else. At this point I'm thinking it almost has to be fuel related. Good thing carbs are up next!!

One thing I was curious about Jethro... what vacuum port are you talking about? I wasn't able to find it in the clymer... is this something that I should be looking for on the #2 carb?


I'm moving the electrical junk to another thread, since I had this post going in so many diff directions.

[Guest]

????

Did it idle? Sounds like you had bad plugs. Are you saying the #2 plug was not wet? Did the pipe heat up?

[J_C]

Oops.. I never actually said that the problem was still there. Duh on me.

The pipe did not heat up. The #2 plug was not wet, not did it smell of fuel. I'm thinking that maybe fuel isn't getting in?

The bike idled on full choke only, and only if I reved it every couple of seconds.