Trying to set the points correctly

[jon v8]

This is the kit;    https://www.venhill.co.uk/universal-2-stroke-decompressor-kit-vdec.html   

Works very well with the lever setup on the left bar underneath the clutch, just the same as all my 4 stroke bikes. I use it to prime the engine with fuel via 2 or 3 kicks, then release it halfway down the next kick. The engine fires up straightaway then. It also makes life easier for the kickstart gears etc, maybe not important on a Yam, but it makes a big difference on a unit BSA engine. 

[Tillerman6]

Ordered the decompression kit from Venhill  in the UK today.  That should help with the ankle once I get the kit installed.  It's a bit pricey, but cheaper than a doctor's visit and less painful! Thanks very much for the tip- I knew that compression releases did exist, but didn't know where to buy one- in this case it will be backordered, but at least it's in the pipeline. 

[Tillerman6]

On 6/4/2021 at 12:56 PM, jon v8 said:

If its kicking back the timing is too advanced. They are not the easiest bike to start because the kickstart shaft is so high up. I'm only 56 but my right knee is not too good, fitting a decompressor into the cylinder head has helped me starting mine mine a great deal.

Jon V8 and Feetup fun-,

Still having that kickback issue- timing is spot on as far as the measurements on the flywheel. Could be the points are worn out-? with the opening timing set perfectly, you can't see that the points are open at all.  At any point on the wheel openings- you can't see any gap in the points faces.  Electrically, though there is a gap, or the plug would not be firing. Before I put this old set of points in, I noted that the bakelite? strip had worn down to about 1.5mm high.  I don't know if that is part of the problem, but there is no way to get anything like the .012" max gap that I have read about on here.  The only other thing that could wear out would be the cam itself, but it does not look worn when I had it off the bike last time. The timing light shows that the timing is spot on for about a 22mm setback from TDC.  Any ideas?  I'm about ready to give up on the points and order a CDI unit for the bike.  If the cam is worn it would cost as much as the CDI unit from Rex's Speed Shop to replace it along with a new set of points.

Jon V8- That's a great picture of the compression release, but what model of engine is this head off of?  It's not an A model anyway.  Looks like it came standard with 2 spark plug holes from the factory!

 

Edited June 9, 2021 by Tillerman6
Saves time and new question for Jon V8

[b40rt]

Again, buy a trail bike with electric start.

Edited June 9, 2021 by b40rt

[Tillerman6]

1 hour ago, b40rt said:

Again, but a trail bike with electric start.

Can't afford that, but CDI and compression release are in the mail.

[feetupfun]

7 hours ago, Tillerman6 said:

Jon V8 and Feetup fun-,

Still having that kickback issue- timing is spot on as far as the measurements on the flywheel. Could be the points are worn out-? with the opening timing set perfectly, you can't see that the points are open at all.  At any point on the wheel openings- you can't see any gap in the points faces.  Electrically, though there is a gap, or the plug would not be firing. Before I put this old set of points in, I noted that the bakelite? strip had worn down to about 1.5mm high.  I don't know if that is part of the problem, but there is no way to get anything like the .012" max gap that I have read about on here.  The only other thing that could wear out would be the cam itself, but it does not look worn when I had it off the bike last time. The timing light shows that the timing is spot on for about a 22mm setback from TDC.  Any ideas?  I'm about ready to give up on the points and order a CDI unit for the bike.  If the cam is worn it would cost as much as the CDI unit from Rex's Speed Shop to replace it along with a new set of points.

My TY250s with the standard points and standard timing sometimes kick back if I give them a half-hearted kick.

If you get an ignition with built-in timing curve and set it correctly it will not kick back. This is because at kickstart RPM, the spark timing is closer to TDC than it is with a fixed timing ignition

[Tillerman6]

Feetupfun-,  As far as the kick- There are several factors involved.   And some days it starts right up without a fuss and other days it will kick back repeatedly.  However, I have found that starting the kick from TDC  or "the notch" which is just my guess- the chances of getting a good start are increased about 60%.  Also how warm the engine is makes a big difference and the throttle position- although putting on the new OKO carb did not help or change the tendency to kick back.

New electronic ignition- I ordered the Clubman ignition from Rex's Speed Shop yesterday (6/08/21) which is advertised as having a timing curve and a strong spark.  It should be here in about a week and looks fairly easy to install.  Rex's makes a "pro" version that has an external switch for an even more advanced "hill climb" sort of timing, but I did not think I needed that option, so I just got the standard Clubman version.

Rex's has a pretty impressive web site and it looks like they have the expertise needed to dial in most anybody's ignition situation with their specialized kits.  I was glad to see that they had a 

special kit for the TY 250, and their prices are a bit more reasonable than any of the competition- ( I think because the installation uses the original rotor)  plus the fact that Partzilla did not have an OEM set of standard points available, plus the cam on my rotor may be worn out, it made sense at the time to try the RSS kit.  We will see in about 2 weeks if this was the right decision, but I have a good feeling about it right now.