HEAD GASKET CATASTROpHI

[XLsior]

there are 2 more smaller bolts mounting the cylinder to the case...


There is no point removing the cylinder until its 100% confirmed the cam follower lock bolt is actually snapped.

[Zapkin]

the bolt on the outside is the one that is snapped. .that round thing below it rattles and moves if the engine runs so i turned it off immediately. further disassembly is coming then. thanks for clarification.

as you can see in the following video, the bolt vibrates and so does the thing below it.

https://www.youtube.com/shorts/t3_4a5OT_yo

[XLsior]

All the bolt does is lock this cam follower pin which stops the pin popping out and dropping the cam followers and spring washer from falling down.


yes it applies some head gasket clamping pressure but the bolt does not impact the 4 main head studs clamping the compression chamber.


If the cam follower pin is currently loose then the cylinder will have to come off...


I wish you could just show a picture of the bolt...


because its basically the main issue that needs to be correctly diagnosed and will determine what needs to be replaced...

[Zapkin]

I will today. but imagine the bolt with everything beyond about 1/2 inch of threads gone..stuck down inside there. but will get picture today.

[Zapkin]

Originally Posted by XLsior

All the bolt does is lock this cam follower pin which stops the pin popping out and dropping the cam followers and spring washer from falling down.


yes it applies some head gasket clamping pressure but the bolt does not impact the 4 main head studs clamping the compression chamber.


If the cam follower pin is currently loose then the cylinder will have to come off...


I wish you could just show a picture of the bolt...


because its basically the main issue that needs to be correctly diagnosed and will determine what needs to be replaced...

also, as I corrected above. it has occurred to me that i turned that bolt the wrong direction like an idiot. i had a running bike and i messed it up with a newb error..super embarrassing!!

the inside nuts though, that is perplexing and probably why its leaking.

oh well, one must admit ones idiocy etc etc ~Abraham Lincoln.

Still going to get picture of bolt.

[Megadan]

Ok, so that outer bolt does not hold the cylinder to the case. All it does is clamp down the gasket around the outside of that pushrod opening/oil drain.

The reason XLsior is wanting you to take good pictures of that broken bolt in the cylinder i the same reason I would like you to do it. I want to see how far down it actually is. If the cam follower shaft can turn that means the broken part will basically fall out once you pull the shaft ( you will want to remove the cylinder.)

To answer your last question, yes that cylinder set would be most of what you need to replacethe cylinder IF it can't be saved. You will need a couple of other things.

1. A new bolt/locator for that follower shaft. Easiest source I know is CSC. You will want a new washer for it too as it is a copper crush waser. Parts 5 and 6 from this link.
https://cscmotorcycles.com/oem-parts...head-assembly/

2. A new cam follower shaft, O ring, and followers. Parts 1, 2, 3, 4 (make sure you get 2 as the part listing may be for a single unit and you need 2.
https://cscmotorcycles.com/oem-parts...-arm-assembly/

10-15 bucks for all of th above, plus shipping.

[Zapkin]

Here is similar product from Amazon.
https://www.amazon.com/Aramox-Cylinder-Piston-Motorcycle-Rebuild/dp/B0BWF98QGK/ref=sr_1_5_sspa?crid=1RNJJDD093DGU&keywords=cg250+ bore&qid=1697288125&refinements=p_85%3A2470955011& rnid=2470954011&rps=1&s=automotive&sprefix=cg250+b ore%2Cautomotive%2C48&sr=1-5-spons&ufe=app_do%3Aamzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1

so that for 71 bucks and 20 bucks from csc shopping list plus shipping plus me using my brains and taking my time = my bike being on the road again?

but still gonna take pictures today.

[Zapkin]

what about this? is this for real????

https://www.aliexpress.us/item/32568...4Ys#nav-review

[Bill Hilly]

Have you checked to see if the cam follower shaft will turn ? I looked at one that I have, and the threads in it don't start right at the beginning of the bolt hole. If you bolt broke on the thread portion, then there is a chance that the cam follower shaft can be popped out. Also , with you breaking the bolt by turning it in the wrong direction, and caused it to break under the pressure of basically pulling down on the head, and since the broken piece now has no pressure pulling at it, I would say it's surprising loose. If the bolt that broke off is not just perfectly flat at the break, then the piece still in the follower shaft won't be either. I would not be too surprised if it would now turn so easy that the right fitting flat screwdriver would not turn it. It wouldn't pick it up out of the hole, but you may get it out with a little magnetic pick up pen, or get creative and possibly try just a small amount of super glue on the end of your remaining bolt, and slowly try to fish it out . Worst case , removing jug, and turn it upside down.

[Bill Hilly]

http://Here is a picture, though not great. Threads don't start till at least 3/16" up in the bolt hole. The bolt hole is also chamfered , and if you can get the bolt backed off with a screwdriver then even if you can't pull all the way out of the hole, but even right now there's a good chance that you bolt is broke of at the threads of the cam follower shaft, and may not be protruding.
The piece that's stuck can't be tight. It would be able to be turned easy with your fingers, if you could touch it. But either way don't pull the follower shaft out, unless you pull the jug. After more thought, just go ahead, and pull the jug , and they you can just hold it upside down, and probably turn the bolt out with a screwdriver.

[Zapkin]

Here the picture

[Zapkin]

Another

[Bill Hilly]

Originally Posted by Zapkin

Another

That will be easy to get out. Even if it won't turn now with a flat screwdriver, you could either just drill a small hole in it, and take an easy out to it ,or just get a small thin chisel, and put a slot in it. Have you tried yet to see if the follower shaft will turn? The bolt that you show has enough thread left on it that the remaining piece likely is not protruding out of the shaft. The shaft may have just been pulled upwards so hard that it may be a little stuck. If the shaft will turn,it will come out right now.

[Zapkin]

The cam follower shaft thing will turn with a screwdriver and you can see where as you turn it it becomes obvious when it's straight up and down but that's how the bolt went down through and I think if you noticing that one picture you can see that it's down inside there what's left of that bolt

[Bill Hilly]

Originally Posted by Zapkin

The cam follower shaft thing will turn with a screwdriver and you can see where as you turn it it becomes obvious when it's straight up and down but that's how the bolt went down through and I think if you noticing that one picture you can see that it's down inside there what's left of that bolt

I see now. It looks like it's turned 90 degrees. It will come out. You may have to play with it, but the broken piece is not holding it. Your pics show up really small on my phone.