Makes sense.quote:
hondy gearboxes get a little notchy when then come up to operating temp. As for the cylinder backfiring or cutting out that is not normal. An overheating honda tends to detonate...a lot. It will sound like pebbles in a coffee can when you first let out the clutch. It could be that your ignition timing is off and causing overheating and backfiring. It could also be fuel delivery. As for the idle quality, you are supposed to set the idle when the bike is warm, which means that if you set it when it was cold then as the bike warms up the idle will drop, if it was low to begin with it will stall.
So you are saying that the fuel in the cylinder isnt completely burning and come of it is reaching the pipes and then igniting? So basically there is something up with the spark? Either the plug is shot or there isn't enough of a spark from the plug/coil?quote:
Backfiring is primarily caused by two things, timing and fuel delivery. backfires out the carb are usually timing, backfires out the pipe are usually fuel delivery although they can also be a misfiring plug (like a bad plug wire - look for cracks in the coil too). From what you describe, it sounds like the pipe is loading up with fuel, I would check for intermittent spark on that cylinder and then go from there.quote:
Makes sense.
I dont here any pebbles and I just had the bike's ignition set and points replaced.
What causes backfiring? Even now and then Ill get a load bang backfire but most of the time its just a soft pffffff and it always happens when I left off the throttle when Im coming to a stop.
Not saying it's over heating just asking it would be possible and if was the reason for my problems.quote:
Just to follow up on what Geeto said, It could also be that the bike is running slightly rich. This shows up with a hot engine because the hotter it is the richer it will run. That is why you don't use a choke on a hot engine. It is already rich enough. Now the causes of the richness could be caused by to big of jets(main and or pilots), dirty air cleaner, changed exhaust pipes, or too high of a float level. Geeto is right in that this is difficult to diagnose without seeing the bike. What do the sparkplugs look like when the backfires happen? Both the same? Dark and oily? Dark and sooty? White and dry? Light brown and dry? How is the ignition timing?
What do you mean by the gears stick? Is it hard to shift from one gear to the next while riding? Hard to find neutral at a stop? Hard upshifting or downshifting or both?
What makes you think it is overheating? Bad smells? Discoloration of the headpipes?
Lots of questions to be answered before a good diagnosis can be made.
Let us know,
Ken
AHRMA 412
Vintage racing - old guys on old bikes
Not sure what oil was put it when I had it tuned up.quote:
Ok, as far as the shifting into neutral goes, that is the usual thing with Hondas of this vintage. It is generally caused by the clutch heating up and dragging a little bit. You may be able to cure it for a little while by replacing the clutch plates, both fiber and steel, and very meticulouslly adjusting the clutch within an inch of its life. This might cure it for 20 minutes or so. The easiest cure is to learn to click the tranny into neutral as you roll into a stop while the bike is still moving. It becomes second nature after a while. As far as the trans dropping out of second can be caused by a slightly bent shift fork or a less than positive shift into second and a weak shift drum detent arm spring. Try being very authoritative in you first to second shifts and see if that helps. If it does then the shift drum stopper arm detent spring is suspect.
As far as your backfire issues go, put a new set of plugs in it and ride it around until it shows the symptoms and then pull the plugs and tell us what they look like( see my previous post).
Ken
PS what oil are you running?
AHRMA 412
Vintage racing - old guys on old bikes
Gee,quote:
about the shifting, popping out of second usually means that the bike was abused (powershifted, etc). However I have noticed a trend amoung younger honda riders (myself being one) of putting pressure on the lever when they are not shifting, either by resting the top of thier foot against the lever (like they are prepairing for an upshift) or resting the sole of their foot on the top between shifts. Any pressure on the shift lever will cause the bike to jump out of gear when you back off the throttle - I found I am guilty of this between 4th and 5th gear since 4th is such a long gear (as compared to 1st and 2nd which are pretty short on a cb750 and require fast shifts) and I have caused my bike to jump out of 4th a bunch of times without thinking about it.quote:
Not sure what oil was put it when I had it tuned up.quote:
Ok, as far as the shifting into neutral goes, that is the usual thing with Hondas of this vintage. It is generally caused by the clutch heating up and dragging a little bit. You may be able to cure it for a little while by replacing the clutch plates, both fiber and steel, and very meticulouslly adjusting the clutch within an inch of its life. This might cure it for 20 minutes or so. The easiest cure is to learn to click the tranny into neutral as you roll into a stop while the bike is still moving. It becomes second nature after a while. As far as the trans dropping out of second can be caused by a slightly bent shift fork or a less than positive shift into second and a weak shift drum detent arm spring. Try being very authoritative in you first to second shifts and see if that helps. If it does then the shift drum stopper arm detent spring is suspect.
As far as your backfire issues go, put a new set of plugs in it and ride it around until it shows the symptoms and then pull the plugs and tell us what they look like( see my previous post).
Ken
PS what oil are you running?
AHRMA 412
Vintage racing - old guys on old bikes
I'm going to try the other stuff and see what happens. Thanks.
I will probably be around sunday if you want to ride over and have me take a look.
