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Posted: Wed Mar 28, 2012 11:01 am
by bonjour
How is your ignition timing doing ?
Maybe the springs are worn, and will cause a wobly timing.
Get the flywheel cover off when it's flip-flopping, grab a timing light, and check if it's bouncing around at idle.
(I believe the timing is supposed to advance at 3000rpm+)
Posted: Wed Mar 28, 2012 11:13 am
by Jlovvorn
It's solid on the nose at idle for both sides, and right at the double marks at 4,000.
Both when running normal, and when the fault appears.
The problem seems to be that, when warm, it starts losing one side at idle, and then stalling.
Then I turn up the idle to compensate, and then it suddenly races up when the side kicks back in.
I am feeling pretty confident that, whether its the carbs, the fuel flow, a coil, or whatever, that the core issue is one side dropping out at idle when the bike is hot.
Posted: Thu Mar 29, 2012 5:08 pm
by Jlovvorn
Spent some time on it tonight, and I really think its the carbs.
Once hot, the bike will not hold an idle, its up and down.
It does better with the air filters off.
The minute you put a filter on, the idle races way up.
It also fouled a plug on the left side, and I think that is why I got the sudden drop in idle the other day.
So, no big drops now, but also no holding of an idle - except with the air filters off.
Runs pretty good with no filters.
Posted: Thu Mar 29, 2012 6:58 pm
by Jlovvorn
Swapped the carbs for a second set - just to see what would happen.
Not one single common part between old and new.
new gaskets on carb flanges and on spacers on the block.
And again, got warmed up, started racing at idle.
Adjusted slide screws down to avoid racing engine, and then it started stalling.
How this F'ing bike can race and stall at idle without it being related to the carbs is beyond me.
Top adjusters all the way in, slides in synch, mix screws at 1 and 1/4 turn.
Runs great.
Just won't idle - with either sets of carbs.
Posted: Thu Mar 29, 2012 7:54 pm
by hillhudson
honesty this was just happening to my brothers Honda cb160. It turned out to be the throttle cable, try and different one if ya can.
Posted: Thu Mar 29, 2012 7:56 pm
by Jlovvorn
Thanks!
I will change it tomorrow. Maybe I should change the throttle body too.
Funny thing is that when it was racing, I put my fingers in the back of trhe carbs and the slides were not up.
It was racing up to 2700 RPM WITH THE SLIDES BOTTOMED.
I pushed them down hard and it just kept on racing.
Didnt think that was possible.
Posted: Fri Mar 30, 2012 3:14 am
by hillhudson
Were your idle screws totally out when you tried this ? If not then your slides weren't bottomed, have a look at the bottom of your slides. One has an R and one has an L make sure right and left are correct. Also it could be your timing sprocket springs. In that case you'd have to pull the head off and replace em. You could do it in a day, do a search on timing sprockets. And read up.
-hill
Good luck,