CA78 struggles going up hills

[garncarz]

Did you install an aftermarket carb kit?

If so, some came with #130 main, which was way too rich for mine....stock was 120.

I recently bought a Keyster KH-0019 kit. It came with a 130 main and a 40 slow jet and a D3 needle. Too much? What was the stock size for the slow jet?

[garncarz]

If the ignition and valve (timing and clearances) are good and the general state of repair of your motor is OK then you are only left with the carb.

What do your plugs look like?

You may need to look at the needle position and main jet to get things working nicely at higher throttle openings.

G

I am going to look at the plugs this weekend. My procedure is:

1. Bring plugs up to self cleaning temperature, i.e. ~15 minutes at 1/2 throttle.
2. 200 yards at WTO.
3. Hold at WTO, cut ignition and clutch in.
4. Stop and remove plugs.
5. Inspect lower portion on insulator nose.

[G-Man]

Sounds good!

G

[garncarz]

These are the NGK D8's that I just pulled. I don't know, but they look pretty good to me. Opinions?

[garncarz]

A good primer on reading spark plugs.

http://honda-tech.com/showthread.php?t=3063102

[G-Man]

They look pretty good, although 2911 looks the weaker of the two....

Have you tried putting the choke on a little when it appears to lose power?

G

[brewsky]

+1

Stock slow jet was 35 on mine.

If you still have the original jets and they are not damaged, I would just clean them good and re-install them and go from there. They are better quality than the replacements, and don't generally wear out.

It is common not to get any increased power from the last 1/4 throttle at given load conditions, even on new bikes.

Air filter clean?

Plug chops are best done with new plugs, as deposits from many miles of part throttle running can cloud those from a short distance at WOT.