First off you have to look very very good at the exhaust port on the head. The old exhaust seal
might still be inside. It all most welds itself to the port. I take a wire brush or sandpaper to clean the soot
away so I can tell colors. Then with a 90' pick, I pick the old seal out and make sure I have a clean surface
for the new seal.
Then I look at the new exhaust pipe. The original pipe has a small head on the end of the pipe keeping the egg shaped
retainer flange on. The new after market pipes have a 1/2" thick flange. The thin flange needs two half moon shaped
spacers to push the end of the pipe into the head so the egg shaped retainercan go over the studs and tighten the pipe into the seal and into the head.
Remember the head does not have a perfect shape at the exhaust area, all you can go by is the nice clean square feeling seat in the exhaust port,
the new seal and the end of the exhaust pipe and if you need half moon spacers or not. If both studs are the same length when you started
then protusion of stud thre the retainer nut will help.
Bill
Portland OR
________________________________
From: "wjbyers@rocketmail.com" <wjbyers@rocketmail.com>
To: Honda-C70@yahoogroups.com
Sent: Monday, June 25, 2012 7:21 AM
Subject: [Honda-C70] exhaust system
I received all the parts to install the exhaust system to the head of my 1981 Honda Passport. I would like some feedback on how the fange should look in relationship to the head. First, I imagine the fange is not flush against the head - that there is some space between the fange and the head. Second, if there is supposed to be some space will the space to equal by both studs - or will there a slightly unequal spacing between the fange and the head. I guess I am wondering if there is some adjustment that needs to be made to the exhaust pipe curve out of the head (although I doubt this). I have never seen an assembled Passport exhaust system and the bike is new to me. By the way, for those of you that have helped me order the correct parts, the stud was not broken off; rather, the previous owner must have let the 6mm nut vibrate loose and the stud must have then also vibrated out of the head. I cleaned up the threads and the new stud when in, no problem.
Thanks, Jeff
[Non-text portions of this message have been removed]
1970-73 C70 Honda Service Manual: http://tinyurl.com/6ebwtw
1970-73 C70 Troubleshooting Guide:
http://tinyurl.com/6ebwtw (scroll to sec.7.1 page 101.jpg)
1980-83 C70 Honda Service Manual: http://tinyurl.com/hu42c
1980-81 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec.18-1 page 170.jpg)
1982-83 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec. 20-28 page 205.jpg)
1980-81 C70 Maintenance Schedule: http://tinyurl.com/z4zn6
1982-83 C70 Maintenance Schedule: http://tinyurl.com/hw35c
More resources for C70 Passports and Cubs:
http://www.shlaes.com/Vehicles/Scooter.htm
http://www.velodrome.com/HondaC70/HondaC70.html
