TOPIC:

If you had a degree wheel you will find that in many cases the crankcase mark and T mark are not exactly accurate and when in line can be a degree or so out from true TDC..
Stock timing is listed at 40 degrees but 38 is known to work better on these engines.

zed1015 wrote: If you had a degree wheel you will find that in many cases the crankcase mark and T mark are not exactly accurate and when in line can be a degree or so out from true TDC..
Stock timing is listed at 40 degrees but 38 is known to work better on these engines.

I checked TDC very crudely with a rubber hose in #4 cylinder, firstly because I swapped out the advancer plate and wanted to check it. I know it was very crud but at piston TDC the crankcase mark did line up with the “T” line on the advancer plate. I changed out the advancer because last fall I didn’t think it was the correct one. I could not get timing retarded to the F mark without the engine stalling. If I turned up the idle to stave off the stall, that then moved the timing F mark (the perfect chase you tail scenario) and I just couldn’t get things correct. Also the breaker plate was all the way to the ends of the adjustment slots. I found what I thought was the correct advancer and installed and was able to get timing to the F mark and below.
Sorry for the long description, just want you to know what has been done. Now the breaker plate is in the middle of its adjustment and bike runs well. Please excuse me but 40deg is advanced correct. As in 40 degrees Before TDC. So is 38deg more or less advanced?
When I set as shown in the second picture it helped response from a standing start. Cracking the throttle at idle before I reset, it would bogg and actually would stall if I didn’t release throttle. Advanced to the stamped F as in second picture helped. Still a bogg or delay in rpm climbing when doing a quick WOT at idle.
Am I closer to 38deg with the second setting? Going the right direction? Can I advance more testing by the seat of my pants or don’t you suggest that.

Than more you get in the opposite direction of the crank Rotation, (away from T or F mark), so more ignition advance you get.

38 degrees is stock timing retarded by 2 degrees so firing closer to TDC (less advance).
I wouldn't advance any further than stock 40.
Apart from my supercharged , twin plugged motor at 32 degs and the race turbo at 27 degs all my carb'd engines run 38 degrees and are perfect.
With pods or open carbs you are always going to bog the motor to some extent when cracking the throttle open and surprising it with tons of WOT air at a stand still , the fuel just can't keep up with the sudden increase of air volume and increase in venturi pressure , especially with no load and worse if done cold even with accel pumps.
It will be a different matter when actually riding under load on the road and any slight bogging, if any, off tick over should be taken care of by a slight tweak of the pilot mix screws.

Scirocco THANK YOU!!! You have been a lot of help here

Zed1015, as always a great source if information and greatly appreciated. I completely understand the rush of air concept. Makes sense.

Well after what seemed like a longer time than normal my 265 shim from Partzilla arrived. I have only set clearance on 2 engines so by far still a rookie. My question is about the shim. I have yet to see one with the number stamped in. All of the shims I have worked with are somehow ink or paint marked. I say somehow because after 42 years you can still read them. Amazing but predictable with these engines. So this was marketed as factory oem. Is it? or should I just get one from another source. I don’t want to ruin a good engine with a 10$ part. Thanks

They knew you were special!

hardrockminer wrote: They knew you were special!

Yes I’ve had a few rides on the short bus , but that’s a story for another day. Are you saying Partzilla was the driver on one of those trips?

I have never seen any stemped numbers on shims (breaking Points) and wouldn´t use any of those stamped shims.
If you are in hurry to get shims talk to your local BMW dealer. Some BMW Bikes use the same 29 mm OD and thickness shim size.

www.tills.de/product-320.html

New Shims OEM Quality direct from plant 29mm

BMW

•E169 (F 650, F 650 ST)   (09/1993 — 04/2003)
•R13 (F 650 GS, GS Dakar)   (02/1999 — 11/2003)
•K14 (F 650 CS)   (11/2000 — 09/2003)
•K589 (K100, RS, RT, LT)   (05/1982 — 10/1991)
•K569 (K 75, K 75 c, K 75 s, K 75 RT)   (12/1984 — 06/2005)

Aprillia:

Aprilia Moto 650
Aprilia Pegaso 650
Aprilia Pegaso 650 Garda

and some Japanese Bikes:

Honda:
CB750C Custom - 1980-1982
CB750F Super Sport - 1979-1982
CB750K - 1979-1982
CB750L LTD - 1979
CB750SC Nighthawk - 1982-1983
CB900C Custom - 1980-1982
CB900F Super Sport - 1981-1982
CB1000C Custom - 1983
CB1100F Super Sport - 1983
CBX1047cc - 1979-1982

Yamaha:

SRX250T/TC - 1987
XVZ12TK/TDK Venture & Venture Royal - 1983
XVZ12DL/DKC2/DN Venture Royal - 1984-1985
XVZ13DS/DT Venture Royal - 1986-1987
XVZ13DSC/DTC Venture Royal - 1986-1987
XVZ12T/TC/U/UC Venture - 1987-1988
XVZ13DU/DUC/DW/DWC Venture Royal - 1988-1989
XVZ13DA/DAC/DB/DBC Venture Royal - 1990-1991
XVZ13DD/DDC/DE/DEC Venture Royal - 1992-1993
VMX12N/NC/S/SC V-Max - 1985-1986
VMX12U/UC/W/WC/A/AC/B/BC/D/DC/E/EC V-Max - 1988-1993
FJ1100L/LC/N/NC - 1984-1985
FJ1200S/SC/T/TC - 1986-1987
FJ1200W/WC/A/AC/B/BC/D/DC - 1989-1992
FJ1200AD/ADC/AE/AEC (ABS) - 1992-1993
FJ 600
FZ 600
XJ 550
XJ 650
XJ 750
XS 400
XS 750
XS 850
XS 1100
YX 600

Kawasaki:

KL 600
KL 650
KLX 650
KZ 900
KZ 1000
KZ 1100
KZ 1300
ZN 1300

They are OEM so I would not hesitate to use them. Some people might believe the stamping creates a stress riser, but when I think about how the cam contacts the shim it's not in that area.

When I had my KZ-1000 apart I noticed there were some inked shims in it and some stamped shims in it. Don't know which is correct, but the stamped or inked surface should face away from the cam. I can't recall for sure, but I needed to replace almost all the shims after the valve job and once again it was a mix of both types. I only have about 175 miles on the rebuild and although the engine sounds great I will re-check the clearances at 500 miles. The "best" deal for me on shims was at the local Kawasaki dealer from their shim kit. They charged me $3.00 for each shim! And they will give me $1.50 apiece for my old ones if and when I want to bring them in. I thought that was pretty nice of them. I probably will never need them, but I am just going to keep the old ones.
Rick H.

Scirocco thanks again. I was searching evilbay and found a small lot for a KLX650 that had the size I need and I few more to add to my stock.