TOPIC:

I want to first thank everyone who has given me advice over the past year since I bought the 73 Z1 900 chopper project. True to form, it has been a doozy of a project. For those that dont know the particulars, I bought the 73 in an Amen Saviour frame with a springer front end. It didnt run and had lots of missing parts. I put it back together and had it running and on the road for about two months before #4 piston skirt hit something in the lower end...maybe the crank gear, I dont know. Fast forward three or four weeks and I find a basket case 74 Z1 in a guys backyard that had been sitting there for like 15 years. Motor wasnt locked up and he wanted $200 for the whole bike....sold! Brought it home and swapped it into the chopper frame. Had some issues with five of the eight carb holder bolts breaking off so I pulled the cylinder head and sent it off to the machine shop to have the broken screws drilled out. Brought the head back and got everything back together and got it running. WOOOOHOOOOO is what your thinking right now and so was I. I was only running it in spurts to try to break it back in slowly so it actually ran three times in about a week and half. The last time it ran was this past Monday evening. Yesterday I go to start it to synch the carbs and it wont start for anything. Didnt matter what I did. At this point I notice that the carbs are sucking in AND blowing out. I checked the exhaust pipes and sure enough, they are doing the same thing. I pulled the valve cover and all the tappets are free moving and working under the cam lobes so the only other thing I can figure is that I have an issue with the valves. As a side note, we did find out that the cam chain timing was off by one chain link until last night. We reset the cam chain to where it should be but I figure the cam chain timing being off may have f'd up my valves?? Any one care to agree or disagree as the case may be?? I would appreciate any help from the KZ gods....

Thanks again everybody,
OldSkool73(74)

first off do a compression test... if thats ok go from there...steve

Fixer5000,

Thanks for the quick response. Unfortunately I have no actual compression testers so I did the old tried and true finger over the plug hole test and there was compression but not enough to blow my finger off of the hole. It was low compression and felt the same on all four cylinders.

Thanks,
OldSkool73(74)

If the valves are bent just a tad, the engine will turn over fine but the valves just won't seal. I would invest in an Autozone compression tester. Get the kind that press fits in the plug hole. They are actually pretty cheap. Anyway, sounds like bent valves. Once you have the head off, you will be able to tell real quick once you have the valve train apart. You will not be able to slide the valves in and out of the guides smoothly and easily. I just got done rebuilding a top end with this (among other) problems. The owner or person helping him had set the cam timing wrong and then put it right after turning the engine over and bending the valves. Probably was off one rivet... easy enough to do.

Take it someplace where you can get a leakdown test done.

Jay