Mean Streak Top End Rebuild

  • by gadget
  • Monday, June 01 2015 @ 05:00 AM PDT
  • Views: 7,717
  • Posted in Maintenance Tips

This story begins with the mysterious disapearance of coolant in my 2002 Kawasaki Mean Streak. I'd check the reservoir periodically and saw that it was empty. I filled it and a day later it was empty without evidence of where the coolant had gone. Eventually, after riding some distance on an hot day, I caught it red-handed as the coolant was boiling in the reservoir and draining from the overflow hose.

(Note: the antifreeze in the mixture is slippery, making directly in front of the rear wheel a less than ideal place to spray extra antifreeze. It does explain all the drifiting I've been doing lately, though.)

I determined that there was a loss of pressure somewhere, but never did deduce where that was. I ran several tests:

  • Gas test, lookin for exhaust gas in the coolant.
  • Pressure test of both the radiator cap and cooling system.
  • Dye test with a blacklight. The only thing with dye on it was the overflow hose.

I'm disappointed that none of the tests that I ran were conclusive, but there was definitely something wrong so I decided to tear into it.

So, here goes... Starting out with the bike in the wheel chock. Not how the manual says to do it, but it seems safer to me than jacks and rubber band around the brake lever. My chock won't fit with the Reaper fender, so it had to be removed along with the chin scoop.

I got the the throttle cables off the throttle body by first removing them from the grip. Hmmm.... I think I need a new cable...

Here the engine is out. My HF lift worked fine, I put a couple of thin boards under the engine to help level it.

Interestingly, I didn't seem to have the pin & spring holding the driveshaft to the output shaft. I think I'll add that to my next parts order also.

At least I have some games to play when I get tired.

Special note... don't forget to disconnect the fast-idle knob before trying to slide the engine out! D'oh!

Here are shots with the rocker covers removed, then the rocker box removed. There are 2 small bolts, 4 medium nuts and 4 large nuts to remove. Apparently the Japanese have unusually large feet, because their idea of 58 ft-lb on the large nuts is far different than mine. According to Tear it up, fix it, repeat: 1500 Vulcan Topend Rebuild, "An impact wrench is highly recommended." Now I see why.

The oil filters are very small and will fall out when you turn the rockers over. You might need to very carefully help them out with a small pick; I found the orange-handled picks from Harbor Freight to work well for this.

Also you have to ensure that the front and rear rocker boxes stay with the front and rear heads. They're machined as a set and there's no gasket between the head and rocker box, just some RTV, so don't mix them up.

 

Removed the front rocker, an old needle-type torque wrench on the 14mm rocker nuts- those supposedly 58 ft-lb nuts took > 100 ft-lbs to loosen!

The valves weren't pictured real well in the previous pic, you can see that the rear-rear cyl. valves have lines worn in them, the front-rear cyl ones are a little more random. The front cyl. valves are worn in a circle. Here's a little better lighting angle.

Some coolant around the base of the rear cylinder, maybe spilled when the coolant hose was pulled off or could be a symptom of the problem.

Head Removal

Here you see the head removed and the top of the pistion with the head gasket. Obviously there's coolant all over but it's impossible to tell if it's due to a leak or spilled during disassembly.

A couple of small nuts at the base of each cylinder allows them to come off fairly easily. There's a little wear apparent on the piston skirt but I'm told this is normal.

Spark Plug Tube damaged by Cam Chain
Unrelated to this project, but you can see a little wear on the spark plug tube. Check out the Cam Chain Tensioner Extenders for the fix. (Extenders were installed, this apparently happened before that.)

Dirty Rear Valves
Dirty Front Valves
Dirty valves. I had a valve job done while the heads were off, which included replacing all 4 rear valves.

Lots of Stuff
All kinds of stuff removed! You can see the "F" and "R" labels on the cardboard to keep track of what went to the front & rear cylinders, with the throttle body right in the middle. Ziploc bags make a great way to keep various nuts, bolts & snap-rings together.

Clean Rockers
Clean Base

While the valves are being replaced and fixed up was a good time to clean up the other parts. Carb cleaner and an abrasive sponge work well to get the pistons clean. For the aluminum mating surfaces you can carefully scrape with a razor blade, but be very careful not to scratch the surface. Remember that there is no gasket between the rocker box and the head, only a layer of RTV.

New Shift Linkage
Another item to handle as long as I'm in there... replace the shift linkage that was bent in an accident.

As usual, taking things apart is easier than putting them back together. This was certainly true of getting the cylinders fitted over the pistons with new rings. Eventually I got the rear cylinder on but the front just wouldn't go.

At one point, it finally seemed to, but while pushing down and trying to compress the rings it suddenly went down quickly. Unfortunately, a couple of things happened here: First, the engine turned without having tension on the cam chains, and second one of the oil rings bent and scored the cylinder wall.

Bent Piston Ring
Kinked Cam Chain
Cylinder Scratch

Needless to say, none of these things were a desirable outcome... this made the job far more involved than it should have been. First, a new cylinder was needed since I didn't care to bore it out and use oversize rings. The scratch was just a bit above where the rings would be at bottom-dead-center. The chain was kinked sufficiently that it needed to be replaced, along with both cam chain guides. Although these are simple to replace, getting to them involves removing both the stator and clutch assemblies. Clearly this "top end" rebuild would require delving further in to the engine than planned.

The left side of the engine is relatively simple, so no pictures are here. Follow the manual to remove the stator and you can get to the lower cam chain guide.

Right Side Parts
The right side is a bit more involved; pay special attention to the two (yes TWO) holes just waiting to gobble up any small parts that you may drop. And there are small parts to be dropped, especially from the water pump assembly. This chain guide is buried behind the water pump, starter gears and the clutch, so it all has to come out. The manual recommends using an impact wrench to get the clutch nut off. Heed that recommendation.

As you can see from the water pump in the pic, I tried to keep things together so I wouldn't forget how it goes back in. I did get a chance to use my extendable magnetic wand to retrieve a small pin for the water pump that went down the front hole. Block both of those bad boys with rags before you start unbolting anything!

Now that the cam chain guides were replaced everything went back

Share It

  • Mean Streak Top End Rebuild
  • 2 comments
I have seen this article with the reassembly before, could you please post that link? Some idiot dropped an intake bolt in my throttle body and it got stuck in between the valve and valve seat while putting a 1/8" gouge into my piston. I am on re assembly and needing the timing set up because I remember you said the manual was wrong. Please help, thank you.
The other article is the one on https://tearitupfixitrepeat.blogspot.com/, link is in the article. There isn't anything wrong in the manual, the only thing is Kawisaki's method of stabilizing the bike seems a little less stable than I'd like.

The timing is easy to get 180 degrees off, you have to time the front first, then rotate the crankshaft to indicate TDC for the rear and set that camshaft. If you miss the mark you need to go all the way around and time the front again, then the rear.