77 Kz650 first bike project-new member

Wow that is a nice looking bike and a great score for $600.00. What makes you think the head gasket is blown, an oil leak or compression leak? I also see you have what looks like the Mikuni VM26 carbs not the standard VM24. The VM26 came on KZ1000 bikes are a little larger and gives a boost in performance on the 650.

that bike is an amazing find for 600
i got my 1980 kz 750 without any tank or seat for 600!!!!!! :woohoo:

I've uploaded a picture to show you guys what i'm sayin' with this head gasket... its pretty obviously blown if you look at picture #1. Picture 2 shows an up close detail on one of the carbs, it would be cool if they were the vm26, I dont have any idea how to distinguish between the two. Is anyone else's engine just decked out in chrome and polished bits? I cant believe how beautiful this thing is. I tried to get the bike started today after installing the freshly sealed tank, and had a small degree of success. Needed a couple shots of starting fluid, but dad and I got it to run for about 5 minutes on full choke. if you tried to give it gas, or turn the choke down, it would kill it. After checking a couple of posts in the carb thread, just sounds like i have a case of dirty carbs, pretty typical for a bike that has sat for 4 years. we sprayed a bit of carb cleaner in them, but nothing intrusive, so thats the next project. And thanks guys! I feel like I got an amazing deal. I think the last guy was just too freaked out about the head gasket job, and just wanted to cut his losses. I talked him down from 800 after it started leaking gas out of the tank

alex_woham wrote: I've uploaded a picture to show you guys what i'm sayin' with this head gasket... its pretty obviously blown if you look at picture #1....

Looks almost too clean in the suspected blown head gasket area, where would usually suspect some gungy black residue.

Won't hurt to verify the suspected leak before tearing down the top end, using powder test and/or poor man's leak down test.

A leak down test is generally a good idea before tear down, because it will indicate which if any valves may also need attention.

Good Fortune!

alex_woham wrote: I've uploaded a picture to show you guys what i'm sayin' with this head gasket... its pretty obviously blown if you look at picture #1........

I do not believe that is a blown head gasket. I believe it shows evidence of a slight leak at the o-ring that seals the oil journal between the cylinder and head (see part labeled "2" in diagram below). This is not uncommon on KZ650 engines and is not a big deal to live with. Just clean that area well and keep an eye on it. You may find a slight weeping of oil there from time to time, but it will not affect the engine's compression or performance. It is very likely that the previous owner let the oil get old and thinned out and what you see in the picture accumulated there over many hours of operation. My best advice is just clean it up and leave it alone. If you keep fresh oil in the bike you will see very little leakage there; most likely just a trace of oil weeping every thousand miles or so. KZ650 head gasket are not known to blow out. Ed

you guys are absolutly right, no point in jumping to the worst case scenario until I have ran those tests. If it is just that tiny o-ring i will be overjoyed.

650ed wrote: This is not uncommon on KZ650 engines and is not a big deal to live with. Just clean that area well and keep an eye on it. You may find a slight weeping of oil there from time to time, but it will not affect the engine's compression or performance. It is very likely that the previous owner let the oil get old and thinned out and what you see in the picture accumulated there over many hours of operation. My best advice is just clean it up and leave it alone. If you keep fresh oil in the bike you will see very little leakage there; most likely just a trace of oil weeping every thousand miles or so. KZ650 head gasket are not known to blow out. Ed

First, sorry to hijack... but is this also common on the 550's? And so you're saying to just clean the area and keep good clean oil in it and it should be fine? I have a similar leak, same area anyways, but it doesn't seem to be an occasional weeping, there's some spots on my garage floor...

It's possible; the KZ550 has similar o-rings between the cylinder and head. If it's leaving oil on your garage floor that's a pretty severe leak from those o-rings. You may want to clean the engine and make sure the leak isn't coming from anyplace else in addition to the o-rings. Ed