Curious - how much difference does a couple of degrees of ignition timing advance make on the performance of the engine? Noticeable or negligible?
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Timing advance question
- Thread starter bosco659
- Start date
Lots of variables... got a specific scenario?
For the most part, most modern engines run about 35° of advance... give or take 5°.
Our XS' are booked at 40°. I, and a few others here run around 35-38°. After playing around with my SG's timing, I couldn't tell the difference between 35 and 40. Performance was the same.
Search for a thread here about "Are we too advanced?" Written by @TwoManyXS1Bs. Has quiet a bit of good info.
For the most part, most modern engines run about 35° of advance... give or take 5°.
Our XS' are booked at 40°. I, and a few others here run around 35-38°. After playing around with my SG's timing, I couldn't tell the difference between 35 and 40. Performance was the same.
Search for a thread here about "Are we too advanced?" Written by @TwoManyXS1Bs. Has quiet a bit of good info.
Thanks Jim, will read up. Reason I ask is I was watching an old vid of the timing on my XS and it looks like I may be several degrees retarded. Didn't know if it was worth adjusting it.
I’m general, it seems timing too advanced is where most run into trouble.
When I get some time and nothing better to do, I need to compare the timing on my two Specials. My XS650SK never complains about 87 octane E0. My XS650SH favors 90 or higher octane (R+M)/2. Timing easy enough to prove or eliminate.
I’m going to check mine this weekend. The video I watched was old and I’m pretty sure I adjusted it last season.
I run both of mine a few degrees retarded and like them that way. Besides warding off any possible pinging, I think the bikes run a bit better and stronger at higher RPMs. I only go a couple of degrees, setting it over by the right slash mark of the "range" .....
So, I figure this puts my idle timing at about 12° or 13°, full advance about 38°. This is actually how the early bikes came for the first few years so if you think about it, we're really not running retarded at all but rather just at the old original timing spec.
So, I figure this puts my idle timing at about 12° or 13°, full advance about 38°. This is actually how the early bikes came for the first few years so if you think about it, we're really not running retarded at all but rather just at the old original timing spec.
These are the timing marks on my case. When I get to it, I’m going to paint a line from the center of the crank to the TDC mark. I think it will be this way, easier to ”see” the crank position relative to the decal markings. One day I might measure and mark all the relevant timing marks on the inner lip of the engine case cover.
The red mark is true TDC as measured with a degree wheel. Since the hub diameter doesn’t bring the mark close to the decal, there’s room for error when setting the timing. Hopefully I can get at it on Sunday
I have no timing strobe light yet and I'm impatient... If I wanna turn my points plate just a smidge to retsrd my timing and try to avoid kickback and backfiring, which way would I turn it? I assume clockwise advances timing..? The engine camshaft rotated towards the front (counterclockwise from the left side of the bike) which means turning it clockwise would help it meet it's mark sooner, yes? Correct me if I'm wrong.
***The screenshot attached is all I can find in the manual***
***The screenshot attached is all I can find in the manual***
Attachments
Correct.
Anti-clockwise to retard
I'm just taking blind guesses without a light... It backfired out of the carbs before. I made an adjustment and now it backfired out of the exhaust. I'm investing in a light that displays rpm and a few other cool things here soon... but I really just wanna figure out my fuel mixture and I gotta have my timing right first lol.
To be honest, I just set them to be level with the mating surface of the bowls.
I can say this though, I turned the screws out to a full 3 turns out and it didn't backfire a single bit. My timing is pretty close too. Gonna make a post on my build thread with a video showing where it's at.
Not sure if it helps .But one way to dial in ignition is to
Draw a line with the pen on the ignition moving disc to the fixed part the points
Move it a little and test Listening to the engine and check if it gets difficult to start
If it shoots in the exhaust it is to late
In the carbs to early
perhaps use pen again
Checking throttle response Blipping
If not helping go back to the pen mark
My throttle responds instantly. It doesn't seem to hang much either... Maybe a tad. I'm chasing an intermittent left cyl. Spark. I cut my wires a little shorter and I'm getting ready to try again.
