Topic: Excellent sohc ignition article... and q's about how my cb750k2 is running...

[amattel]

I just read this article and I felt I learned a lot from it.

I am using a dwell meter to tune my bike and the last time I did it I set both sides to 49degrees (4 cyl scale).

According to this article there are performance benefits that come from setting dwell actually at the low end or even below what the recommended range is (46-49 degrees (4 cyl scale))

Has anyone tried this?  Have you noticed a difference?

I find that I recognize when my bike needs to be retimed/gapped by the loudness/roughness of the exhaust note adn the lack of power off of idle.

I have also noticed the after I retime/gap it it seems to take a bit of riding time before it seems to "settle in" to the new settings...  Does anyone else notice this with their bikes?

The only way I can decribe it is is seems to run "tight and quiet like a sewing machine" right after I tune it and after riding it a while it gets slightly rougher and feels more powerful and a little louder..

When it gets a lot louder/rougher is when I know it needs to be done again...

Also, tuning it gives me wonderful power off of idle for effortless startups...  when it needs tuning it loses that off-idle-ease...   

I have also noticed that when I have the most power off of idle, I have the least at mid throttle.

Any insights as to what all these perceptions of mine actually mean in a technical sense?

I feel like I am actually connecting with my bike for the first time 

Adam

[Bob Wessner]

I just read this article ..

Where did you find the article?

[Gordon]

With any breaker points set-up, there's always going to be that "sweet spot", where the bike runs best.   When dealing with points, I've always set them just a little wider than the ideal setting, because the nylon rider that rubs on the timing cam slowly wears down, and the points slowly get closer together.  By setting them slightly wider, it maximizes the time that they're in the sweet spot.  But that's just how it worked for me, and maybe it was all in my head.

 And then I started thinking about it too much, and I was always trying to get it to run just a little better, and I was always adjusting and re-adjusting to try and get it perfect, and it was always just one tweak away...

You've got the sickness.

Welcome!

[Terry in Australia]

Buy yourself a Dyna S mate, and you'll always be in the "sweet spot"! Cheers, Terry.

[Gordon]

Buy yourself a Dyna S mate, and you'll always be in the "sweet spot"! Cheers, Terry.

Couldn't agree more!  I've put the Dyna-S on all my sohc4's, but coming to terms with the points is sort of a right of passage with these old bikes.  Kind of like the first good carb cleaning and rebuild. 

[amattel]

oops!  I forgot to include the link.

here you go

http://www.motorcycleproject.com/motorcycle/text/sohcign.html

[mrbreeze]

Hey Adam,MrBreeze here.Yeah I read that article before and it is good but like these other guys are telling you and if you can aford it,go electronic and you won't regret it.Well I never did hook up with you to go riding this past season but maybe we can this spring.I was kinda late getting mine all together but am looking forward to gettin' up into the mts. soon. I don't know if you are still in Berkely or not but if you are,it's not to far away.Did you add a windshield to your bike?

[MRieck]

Hey Adam,MrBreeze here.Yeah I read that article before and it is good but like these other guys are telling you and if you can aford it,go electronic and you won't regret it.Well I never did hook up with you to go riding this past season but maybe we can this spring.I was kinda late getting mine all together but am looking forward to gettin' up into the mts. soon. I don't know if you are still in Berkely or not but if you are,it's not to far away.Did you add a windshield to your bike?

If I remember correctly you have the Dyna 2000 which makes the Dyna S look like points!

[amattel]

HI Mr. Breeze,

Yes.  I am still in Berkeley.  I graduate in MArch and will probably be around for a couple months after that.

It would be great to go riding with you sometime.

I will be riding down to L.A. next Thursday for the holidays.  The bike is running great (other than the oiil leak I haven't been able to locate...  gonna take off the front sprocket and see if it is hiding there.

My intention is to do the dyna s thing as soon as I can swing it.  In the mean-time I am bonding with my points *smile*

Adam

[mrbreeze]

Hey Adam,I think you are crazier than me if you are heading to LA at this time of year(too damn cold!!!!) . I'm going to Vegas on the 24th but I'll be taking the truck with the kick ass heater thank you very much!!!Watch the weather reports for snow on the Grapevine. BE CAREFULL!!! Hey Mike.. I love the Dyna ignition but don't see any advantage to having all of the advance curves and all because the instructions say that the different curves are for bikes that have 4 valve heads. I guess that if you are really into Hi-Po race engines,they would be good. Hell,I don't know...maybe if I experimented a bit, I could get better results but I am happy with the way its runnin' now. I got them big fat 137.5 main jets dialed in pretty good and I am satisfied (for now!!!)