Backfiring causes?

[Skateguy50]

Only took 9 pages to get you going again.

Glad it worked out for you without having to open the engine up and do a top end rebuild, most of us would have been to frustrated and dug in deeper right away. Your patience paid off and riding in the fall is your reward.

Been a while since I read through this thread, now I got to find the Princess Bride reference. One of my all time favorite movies. Now that you avoided the flame spouts and the lightning sand just look out for those R.O.U.S.'s

[Allie]

I didn't see any R.O.U.S's but I did have a vicious attack rabbit lunge at my throat tonight. After a little twiddling I got the bike running well enough to ride it!

Here's the patient hooked up to an IV of gasoline:



And a close up, ticking over nicely at 1500:



I took a video of the shakedown run, but you can't see much besides darkness and lights, nor hear anything but wind because I didn't put the wind sock back on my camera yet. I'll take a better vid this week.

The bike runs so bloody WELL now! Boy it's really true you don't notice incremental changes very well. I knew it didn't have that top end rush the way it used to, but it pulls so much harder now right off of idle all the way across the board. I was grinning from ear to ear inside the helmet tonight! It also starts pretty much instantly when cold, and warms up to where it doesn't need the choke after a minute or two. It's never done that before, I venture to say this is the best the bike has ever run for me.

Thank you all so much for your help, indulgence, and patience - I'll be posting a video soon, and will surely grab a riding tag or two at the first opportunity!

Sincerely,

Allie 'The Hammer' Babble

[Skateguy50]

Congratulations on getting out for a ride again, nothing beats that feeling after a few weeks of withdrawal.

Funny you mention the rabbit, saw an ad for spam a lot playing up in Worcester... but I already got plans to be camping and hiking that weekend.

[almarconi]

Did you ever get the broken exhaust stud out?

I just broke one on my KZ 750 and am going to attempt to remove it. The stud broke below the surface of the head so this is going to be fun

[Skateguy50]

I have a feeling she has that pipe installed with 1 solid bolt, but maybe she got it out. (I know I would just slap it on an call it good till winter)

[almarconi]

I know I would just slap it on an call it good till winter

Since its a project bike, I'm in no hurry. Would prefer to replace all the studs with new ones while I have the exhaust off the bike.

[Skateguy50]

Ahh, well I more meant with her bike being unriden for a while if I was her I would ride it either way. However for you it sounds like your best bet is to take your time and pull the head.

You can drill and helicoil it much cleaner that way, and if you need to take them off a lot (some folks need to remove the pipes to change the oil) I would go with studs. I just put new ss bolts in with antiseize on mine and called it day.

[Allie]

Yes I did slap the pipes on with the the broken bolt still in. I tried a couple of times to fire up that MAPP torch, without success. I followed instructions but I'm still not getting it right.


At any rate the pipes are coming back off this winter. I cleaned them up quite a bit, but over the winter they will get some methodical attention in my basement, and I'll have that time to work on the bolt too. It seems pretty solid now, there's no weight or pressure to speak of on the one good bolt. The pipe fits snugly in the head, and the bottom weight is supported by the muffler, which is solidly bolted to the frame. I figure I will just check it often for loosening if I do much riding in the mean time.

[themess]

Good approach. You get some giggles now. Endless wrenching isn't much fun. Riding reminds you why you wrench, provides energy for taking care of exhaust over the winter.

[Skateguy50]

Dont you just love happy endings!

Maybe you should update the first post for those that find this later in a search with the final solution, MUCH smaller shims.