bad sunday

My Sunday ride went real bad. I had done a 190 mile ride Saturday and thought I would take a shorter ride. It started just fine till I was about 18 miles from home with one large mountain behind me and starting up the next one when part way up the bike started making a bunch of banging,rattling noises and dropping the right cylinder along with popping out the pipe.I got off the road and and shut it down, after looking for the worst like a whole in the engine cases and finding nothing abnormal I kicked through to find one side had no or low compression. Out came the cell phone and it had NO service so as it was down hill towards town I figures I could coast down to find service. After a 2 mile slow quite ride down and no service I thought what the heck and kicked it through and it fired up but on one hole and no strange noises so I figured the damage was done and road it all the way back home with it trying to hit on the right side. after looking in the right float bowl for water I pulled the plug to find the gap closed up. after opening up the gap and putting the plug back in it ran perfect, no noises, misses, and compression on both sides, nothing except it now idled at 3 k not 1k. after a little thought I pulled the top off the right carb and found this



I replaced the slide Monday and went for a 200 mile ride Tuesday and it ran perfect all day. I am going to leave well enough alone for now but I know the piston top and chamber is dinged up and will need attention along with the valves but for it looks like I dodged the bulled for a while.

windy

Is that a plated slide? If so do you think that could have contributed to the failure?

That slide probbaly had a crack in it and that piece fell off and passed through. The slides are made of Zamac, a fairley soft material and may have not caused much dammage. While rattleing around in there it smashed the plug gap closed and parts of what was left probbaly got under the exhaust valve. All may be well, but I would check valve clearnece.

Ken G.

some time ago some one asked if the chrome plated slides went brittle, I guess that may answer their question

Thanks for that Bill, and others.
I was thinking of going for chromed slides in my new mk1 amals.
I don't think I will bother now.
I chromed the diaphram spring on the clutch on my Triton. The chrome cracked in one spot but as yet it has not penetrated to the other side, so I think at the moment the spring steel underneith is sound.
There is a shiny mark on your slide at the root of the slot. Is that where the crack started? Is it anything to do with where the throttle stop actuates?
Stu.

Ya might wanna consider blowing compressed air into that cylinder through an exhaust or intake valve with the plug out. If there are any big chunks left in there you'll see them swirling around.

it was a plated slide. as I have heard of it before and Ludwig has also had it happen I don't think the plating had anything to do with it.
Ludwig what did your engine look like when you did take it apart ? I am leaning toward having Bruce Chessel sleeve a pair of carb's. he uses the amal slides so you keep the choke v others that use a mikuni slide and no choke. just worried that it could do it again. the other option is a pair of brass slides but at 60 quid + shipping that puts at over $100 apiece v $65 for the sleeve job and a better fit of the slide from Bruce.
after a 200 mile ride after replacing I think all remains have left the engine :mrgreen:

windy

do the resleeving its worth it !!!

I'm with Blaise on this, resleeved Amal's are great value carbs on a Commando

Cheers,
Per