2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: Pravin on September 01, 2021, 10:07:33 AM

Title: Crank nose Play and Points Timing
Post by: Pravin on September 01, 2021, 10:07:33 AM
Hello Experts ,

I have been working on Getting my bike converted back to points for past 3  months ..

The cam I got had the PIN removed and i had to time it at 2MM BTDC and was successful but then it slipped ..

So I put the pin back and now with the standard cam pin its firing at 3.5 MM BTDC fully retarded points plate.

Then I checked my crank with Dial gauge and magnetic stand and it found 0.15mm deviation on the crank nose .and as per the manual I have its limit is .03MM

Now question is will tat affect the timing ? or add up to the timing ? I am about to open my engine and have the crank balanced ...the question comes in my mind is my CDI set up was working well and firing at 2mmBTDC but not the points .

Need some guidance on what direction I should go and whether the crank rebalance will help .

Set up

Stock RD350
Original new points set to 0.35mm gap
Original new cam
Generator and Magnet is used but in good condition no issues there as the battery is charging , voltage is around 13 to 14.5V during the ride ..the first time before the cam slipped...

Regards.
Pravin Dalvi





Title: Re: Crank nose Play and Points Timing
Post by: m in sc on September 01, 2021, 10:21:19 AM
i have never ever heard of that on a mis-clocked points cam. Is the rotor slipped? is the woodruff key in? Are you using cams and cranks from different markets? id redrill the points cam and relocate the pin.


.. have to ask, why swapping back to points?

Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 01, 2021, 10:39:12 AM
Hi SC ,

Yes the pin has been relocated , even  I used a standard cam which has the original POIN and original location from my friend ..
No Rotor was at place the woodruff key was on it place when i pulled the magnet out...

Swapping back to points :) ---- I know ... all are going forward and am backwards , been owning RD since last 20 years , first RD CDI since I bought , second bike TCI since I bought -- converted to MZB and Cafe ..

Now the first bike I was saving for MZB and then thought I never experienced the POINTs bike and decided to get my first RD running on points and then base line it and decide whether to continue on points or go MZB route which I think I can do anytime when I have the money .

Points conversion is also not cheap thought :)) spent half of the MZB cost already ;)

But yes am really keen on getting this set up work ..I can re drill the stock cam and relocate the pin but does it solve the problem ? does the .15 mm play has an impact ? how can I retard her more from 3.5 mm BTDC to 2MM BTDC without relocating pin ?

Cheers ,
Pravin

Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 01, 2021, 11:08:17 AM
This is how I measured the play

https://youtu.be/V9T3E9bkzz0

On spare crank also I have .1 mm play
https://youtube.com/shorts/Eu3UC8HtS7k?feature=share

So question is shall I re drill my cam , move the pin where it gives me 2mm leaving the crank with this play ?

Or rebalance or rebuild and use and will thay give me standard timing ?

Cheers
Pravin
Title: Re: Crank nose Play and Points Timing
Post by: m in sc on September 01, 2021, 11:08:25 AM
YOU CANT. SOMETHINGS OFF. I WONDER IF THE WOODRUFF KEY IS DIFFERENT FOR CDI BIKES,(assume that what this was?)  or soembody sold you the wrong points cam. Im not sure whats going on there
Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 01, 2021, 12:00:56 PM
Hi SC ,

So the crank play that am experiencing has nothing to do with timing ?

I have got the used set up from my friends bike only points are new ... Cam I have tried 2 same results ..

Any thoughts?
Title: Re: Crank nose Play and Points Timing
Post by: m in sc on September 01, 2021, 12:11:03 PM
play isn't going to throw it off that much. it needs to be addressed but i have given my thoughts up top. when crank is finished being rebuilt, then go at it. until then just wasting time. I think you have mismatched parts


Title: Re: Crank nose Play and Points Timing
Post by: 1976RD400C on September 01, 2021, 01:37:59 PM
If the points gap is too much it will cause excessive spark advance.
Title: Re: Crank nose Play and Points Timing
Post by: bitzz on September 01, 2021, 03:30:53 PM
Quote from: Pravin on September 01, 2021, 11:08:17 AM
This is how I measured the play

https://youtu.be/V9T3E9bkzz0

On spare crank also I have .1 mm play
https://youtube.com/shorts/Eu3UC8HtS7k?feature=share

So question is shall I re drill my cam , move the pin where it gives me 2mm leaving the crank with this play ?

Or rebalance or rebuild and use and will thay give me standard timing ?

Cheers
Pravin

Yamaha says 0.03mm radial runout on the crank...if I'm reading your dial indicator right, you have 0.15mm
You need a crank.
Title: Re: Crank nose Play and Points Timing
Post by: pidjones on September 01, 2021, 06:42:01 PM
Your crank certainly seems to run untrue. This needs corrected first.
Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 02, 2021, 07:45:46 AM
Got my crank balanced today ....with bearings on its withing .03 to .04

Hope am good , will install it and see if am getting any help in timing ..

https://youtu.be/I-ELqBrpo3A

Regards,
Pravin
Title: Re: Crank nose Play and Points Timing
Post by: teazer on September 02, 2021, 10:26:52 AM
Why do I recall a post somewhere that said that CDI cranks had the keyway 90  degrees different to points cranks?  Of course I can't find that posting now or remember who posted it.. :whistle:

Someone should know the answer, but it should not be hard to re-clock the points cam.
Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 02, 2021, 11:25:25 AM
Ok just to add or clear the CDI part ..

My Bike was originally on points and not on CDI Originally ..... then was converted to CDI ..and when she was running on CDI the key was still in the same slot  on the crank  , yes position in magnet may be different .

But now am just going back to points so the original magnet is matching the key right ?

Cheers,
Pravin
Title: Re: Crank nose Play and Points Timing
Post by: m in sc on September 02, 2021, 11:35:03 AM
should be.

If i remember correctly, the keyway should be straight up when #1 is at TDC.

Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 02, 2021, 12:39:42 PM
Great !

I am going to do the crank swap over weekend and Monday .... Will install the ignition and update how it goes fingers crossed

Cheers
Pravin
Title: Re: Crank nose Play and Points Timing
Post by: bitzz on September 02, 2021, 01:23:40 PM
Quote from: teazer on September 02, 2021, 10:26:52 AM
Why do I recall a post somewhere that said that CDI cranks had the keyway 90  degrees different to points cranks?  Of course I can't find that posting now or remember who posted it.. :whistle:

Someone should know the answer, but it should not be hard to re-clock the points cam.

The CDI RD crank was a RD400 and the Rd400 CDI had a keyway that was 90 degrees off  the later RD-LC and RZ CDI models.
The CDI cranks also had a different taper from the points models.
Title: Re: Crank nose Play and Points Timing
Post by: m in sc on September 02, 2021, 03:34:15 PM
what about the Indian cdi 350s..?
Title: Re: Crank nose Play and Points Timing
Post by: Pravin on September 02, 2021, 04:38:47 PM
Thanks Bitzz for outing some light

Indian RDs are basically RD350 A what you guys have  there ..

Same crank , the one in my videos .. already in the engine is indian crank adn the spare one at home us USA one  both are interchangeable , am using usa crank on my cafe with MZB

Cheers
Pravin
Title: Re: Crank nose Play and Points Timing
Post by: m in sc on September 03, 2021, 08:02:56 AM
you checked the keyway clocking vs the 2 cranks?  :umm: :whistle: im thinking thats where the disparity is.  either way, reclocking the points cam is the easiest solution at this point.
Title: Re: Crank nose Play and Points Timing
Post by: Dvsrd on September 03, 2021, 12:26:03 PM
Quote from: Pravin on September 02, 2021, 07:45:46 AM
Got my crank balanced today ....with bearings on its withing .03 to .04

Hope am good , will install it and see if am getting any help in timing ..

https://youtu.be/I-ELqBrpo3A

Regards,
Pravin
0.03 to 0.04 mm I hope?