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Post by bk2112 on Dec 30, 2021 19:09:59 GMT -5
I just got my replacement points cam and noticed that there is an 11 and a 13 on it. The one I took out was so rusty I did not notice the numbers when I pulled the weight springs off and removed it. The numbers seem to correspond to the drive pin notches but I have no idea which notch the drive pin should be in...if it matters?
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Post by timpa136 on Dec 30, 2021 19:31:03 GMT -5
Yes it does matter. You may find this in the service manual page 83 or so here on the board references.
Tim
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Post by timpa136 on Dec 30, 2021 20:00:41 GMT -5
Whoops!
Service manual correction is 13. 13 is correct,changed from 11.
Thanks for the reminder.
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Post by bk2112 on Dec 30, 2021 20:38:32 GMT -5
Got it looked up in my manual! It's the 11 mark. Thank you!!
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Post by wayne on Dec 31, 2021 20:03:41 GMT -5
Got it looked up in my manual! It's the 11 mark. Thank you!! the manual is WRONG. What Tim said. An addendum came out for the manual to correct errors. One of those errors is on page 79, under d. Reassembly, point (a), third line where it says "weight plate into the notch marked "11" You must change the "11" to 13. |
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Post by bk2112 on Jan 1, 2022 13:41:08 GMT -5
Thanks to the both of you! I mis-read Timpa136's response. Set it to 11 yesterday. I'll go back today and move it to 13. Those little springs are a bear! Just glad I came back to this!
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Post by hudson on Jan 1, 2022 14:25:20 GMT -5
 I agree Tim and Wayne are correct as per Service Bulletin RE3 regarding corrections to the service manual. I thought I would share something I learned during my restoration.
The photo above shows a plastic bushing around the pin in the 13 notch. This is only mentioned in the service manual on page 78 - Figure 8-11 as a roller. The only one I have seen in place is the one in this photo that is a 5,000 mile bike. I found pieces of one in the bottom of the ignition housing on my restore RE and began an investigation as to what it was.
Using the carb. protractor I found that without the bushing it allows 18 1/2 degrees of rotation not the 13 specified, this results in an additional ignition advance of 2 X 5 1/2 = 11 degrees of extra advance at the eccentric shaft at high RPM if static timed. Also less spring tension at idle speed allowing the timing to start advancing prematurely. (Fluctuating timing at an idle as seen with a timing light )
The bushing I made can be seen in the picture was made from UHMW plastic, dimensions are 4mm i.d. 6mm o.d. and 5mm wide. This restored the advance to the 13 degrees spec.
I have to believe that most RE's are missing this bushing by now and are running with an over advancing ignition timing, unless they are very low miles. The original in the first picture appears to have been made with a split design or is already cracked.
The ones I have found pieces of are the color and hardness of dried grease. Mine is a solid bushing and I was able to pushed it over the head of the pin.
I am curious if anyone else has found this ? This can be checked for by just removing the points plate held by two screws.
Brian |
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Post by janski on Jan 6, 2022 11:23:38 GMT -5
 Out of curiosity I dismantled a points housing, and what Brian described is what I also found. Nice one Brian. |
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Post by wayne on Jan 6, 2022 17:35:02 GMT -5
Thank you Brian. Very interesting, I don't know how I missed this post. I'll be peering inside my points housing, pretty sure that bushing is not there.
Some time back a non-RE friend criticised the design of the RE advance mechanism and to demonstrate, used a timing light to illustrate the fluctuating timing at idle on my rider bike.
In his opinion this was due to a poorly designed advance mechanism with too small a diameter for consistent spring action on the mechanism.
Missing this spacer/roller certainly wouldn't help.
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Post by timpa136 on Jan 7, 2022 17:58:12 GMT -5
Thank You Hudson for making that so clear. I admit I haven't paid close attention to the bushing
and you pointed out the excessive advance that could definitely cause internal damage.
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Post by hudson on Jan 8, 2022 8:22:58 GMT -5
I am not sure if this over advance would lead to internal engine damage from detonation as would be probable in a piston engine, ( Rotary engines low compression ratio and love of low octane fuel )
But sure to be a horsepower killer at high RPM as most of this over advance is probably occurring above 5800 RPM where the advance curve is suppose to end. But I think it is probably ahead of what was intended going up through the RPM and at cruising speed.
Brian
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