Tumbleweeds 1977 KZ650 Rebuild/Reform (Pic Heavy)

Well now it's worse.

Even a little blip of the throttle it goes to 4-6k RPM and just hangs there. If you really crack the throttle hard a couple times it will come back down to idle.

All I did was set the point gap(was a little too loose) and clean the points.

It hung a little before but would always slowly come down. Now it wont.

I tried turning the fuel screws in all the way and still the same effect.

Went to 17.5 pilot, up from a 15, and a 105 main, up from a 97.5

I'm confused how this engine is getting enough air and fuel with fully closed throttle to run 6k RPM...

I should also mention that I cleaned/lubed the timing advance with no effect.

My carb sync port caps were full of fuel, is that normal?

Yes, that is normal.

I'm not confused anymore, I thought about it for a while last night when laying in bed and it makes perfect sense that I have big issues with air leaks. Other than the carb holders, what are likely sources of leaks?

I will use some carb cleaner and poke around to see if I can get any response.

New carb holders, bowl gaskets, drag bars, and other little misc items show up tomorrow.

Here is a photo of the turn signals mocked into place:

Well I got my new carb holders yesterday and put them on. Man do they look much better than the ones I took off.

STILL IDLES HIGH! Bah! Sprayed cleaner around the boots and got no response.
The idle screw is backed off all the way, not even touching the throttle lever.

Electric start works great and no choke needed, it wants to idle at 3000RPM.

If you touch the throttle even a hair the idle goes up to 4000RPM and stays there.

Strange thing is, when applying the choke lever the idle will gradually rise, until about 3/4 choke where it is highest. When full choke is applied, the engine falls down to 900RPM and idles very rough.

Any other ideas? Could I be leaking air from somewhere else? Could my slides be adjusted too high?

17 pilot, 105main, 4th clip needle, 1-1/8 fuel screws.

Slides may be too high. If the idle control screw wasn't around its mid point when the bench sync was done it may not be controlling the idle at all. Ed

My carb slides were in sync, but all were adjusted too high, I lowered all the slides and bench sync's them again with proper gap from idle screw to throttle bracket.

Timing was also a bit too far advanced, so I brought that back to the "F" hash.

Idle is VERY NICE!

Now I am back to the original problem I had. Bog off of idle. Any sort of load and the engine wants to die. With very light throttle I can get RPMs up high enough to get going, and while cruising anything over 1/8th throttle the engine bogs down, so the only way to accelerate is with very light throttle.


The hanging idle is gone, but if you clutch in and cruise to a stop, RPM will stay high. Engaging the clutch a bit to slow the engine down will then allow the engine to idle as normal with clutch disengaged.

Tumbleweeds wrote: .....Now I am back to the original problem I had. Bog off of idle. Any sort of load and the engine wants to die. With very light throttle I can get RPMs up high enough to get going, and while cruising anything over 1/8th throttle the engine bogs down, so the only way to accelerate is with very light throttle.......

Sounds like you in for more pod tuning fun. I love my airbox! Ed

650ed wrote:
Sounds like you in for more pod tuning fun. I love my airbox! Ed

I cant believe that this is only because of pod filters.. The machine barely runs at all.

I'm going to start by triple checking timing.

Here are plugs 1-4 from left to right.