Hattori Hanzo - Bonneville Racer

[jaylinb]

I've been racing at Bonneville since 2012, and last year bought a beautiful 1969 CL175 from eBay to enter in the Classic racing class. Here is her story...

Below is how she looked online, and when she arrived. A vision of Honda twin splendor.

 

[jaylinb]

I got the bike in February of 2013. Once I started riding her around though, I started to find some problems. First, she was hard to start, and often would lose a carb due to sticking.
Then one day a spark plug popped from the head on a high speed run, stripped completely out. I figured it was time to take her apart and start building her for Bonneville in August.

 

[jaylinb]

The engine was taken out and a full top end rebuild was done. I discovered several things: first of all, someone LOVED safety wire. The drive chain was being held together with safety wire, and there was crazy all over the valve cover bolts.

 

[rundown]

This should be very interesting, I know next to nothing about Bonneville, sut suspect I will soon.

 

[jaylinb]

Found lots of lovely gray goop being used as the valve cover gasket, and one of the pistons had experienced a valve drop sometime in the past that was never taken care of, so I gently worked it over until the top was reasonably smoothed out.

I then sent the pistons off to Swain Tech coatings for Teflon skirting and ceramic top coating. The lifters I sent over to Mega Cams, and the head went to local porting shop Harold's Machine Shop to Heli-Coil the plug hole and port for better top end.

 

[teazer]

Nice little bike. Most of that lockwire is required by almost any race organization. The head dome nuts are not usually wired but in theory at least two of them contain oil under pressure and should be lockwired according to AHRMA. Not sure what the tech/safety rules are for Bonneville, but I guess you do.

That piston looks odd. Usually a dropped valve impacts the valve pocket and then beats the whole piston crown into a pulp.

Nice job that Megacycle did on your rocker arms. Did you also fit a hotter cam while you have the top end apart? They offer few grinds. We find the mildest one to work best with most motors.

Air inlet could be improved there and the footpegs are very low. You may find the riding position more suitable if they were an inch or two higher so you can tuck in tighter and for the track, narrower bars would keep you elbows in out of the wind.

 

[jaylinb]

Oh yes, this was just the start of the build last year... I have at least 40 more pictures to post. Thanks for the kudos, I was very pleased with Mega Cams. We decided to just clean up the current cam this time around, I didn't want to mess with things too much the first year out.

For our racing, drilling those head nuts was a dumb thing to do. You weaken the nut by drilling and any weakness WILL be found and ruin your day. We never drill the head nuts and AMA doesn't require half the wire the prior owner added. But he never even wired the axle nuts, which IS required for LSR racing. I'll post up more of the build later.

 

[Barnburner]

Glad you started a thread. I'm tuned in for sure! Also, I believe the original builder is a member on here (user name "Boobby").

 

[teazer]

Agree that drilling those nuts is nuts. Way to easy to break through the thin crown and let all the oil out. That would surely ruin your whole day.

We don't wire our wheel (axle) nuts. It's quicker and easier to use an R pin/axle pin and wire the two open ends together so it can't be accidentally knocked off.

 

[1sttimer]

I'm in! Nice bike!

Shameless plug: if you ever want to part with that exhaust, let me know!