Troubleshooting Part 3

[BPT]

Hello again. I finally had time to get into the carbs.  Who would think that "I hope I find a tear in the diaphragm" would be something a guy would say?  In this case, I'm happy that a tear is what I found.  Oddly it was on the opposite side of where I thought I was having problems when all of this started.

I did not do a complete rebuild but I replaced both diaphragms along with the needle jet, jet needle, main jet and atomizer (all of the stuff in line with the piston).  I did get the complete kit so I can do a full rebuild later.

It's been sitting for several weeks but it did fire up pretty easily.  I played around with it a bit and got it to idle steadily (as in it doesn't die) but it sounds "off" for sure. 

I suppose I need to start from scratch and set up the carbs now.  My next question is regarding timing.  Is that the last thing I should check?  That was the last thing that was done and so I'm wondering if it was done with the badly running carb, what effect will that have?  Do I try and dial the carbs in now and then recheck the timing?

I haven't gone for a ride yet but I am hoping that I've dodged a bullet with the Hall sensor now and just need to get the carbs tuned again. If I can get out and get it over 55 mph then I'll know I'm on the right track.

Thanks for all who have followed my posts and replied and thanks for your suggestions for the best next step(s).

[tunnelrider]

Have you bought a timing light yet BPT? Have you got the Clymer Manual? Section 3 Tune Up sequence explained very clearly.

[BPT]

I have not gotten a timing light yet but I do have access to one.  I do have the Clymer manual and was just about to thumb through that now.

As for the timing, I was just wondering if doing it while unknowingly having the ripped diaphragm means it needs to be done all over again or will it just be the carbs that need to be done.  Kind of like the advice I got early on that I needed to do the valves before anything or I'd never get it running correctly.

I promise I've got greasy fingerprints on my manual!

[mrclubike]

Timing should be good
As long as it was done at the proper RPM

[BPT]

Yeah, it was done properly. That was a few weeks back when I had my local shop helping me.  When I left the shop I was still having some problems at highway speed and between here on the forum and the shop it was either carb related or ignition.

It wasn't until today I was able to get into it and found the ripped diaphragm.  I just wanted to make sure I wouldn't be frustrating myself trying to tune the carbs if the timing could be off because of that.  Going around in circles....

       Thanks.

[tunnelrider]

As you've probably read and established the timing should be done before fettling the carbs. With a timing light it is easy to adjust to get it spot on, centre of the timing hole. Set timing first at idle speed and then check 3500rpm, at which should be at full advance. If you can't get it in the middle at both idle and full advance set it to be in the middle of the timing hole at full advance.  If you can't set the timing at full advance it's not likely to be the carbs at fault.

[georgesgiralt]

Hello BPT,
Tuning start with mechanical, then electrical, then mixture.
I.E. you adjust the valve lash first, then start the bike and check the timing and lastly ride the bike to warm it up and adjust the carbs. Low RPM balance (idle) above idle balance (cable stops) and then, adjust the idle mixture /idle stops to have a smooth idle at prescribed RPM.
Frankly, you will get accustomed to this procedure and perform it very fast. Faster if you have an electronic ignition because it will not need adjusting only once in a while after having been disturbed...

[BPT]

Looks like I'll do carbs-re-check timing-fine tune carbs.

      Thanks for replying.