Need help 84 DOHC 650 feels likes its running on 2 cylinders

If it's broken or just needs tweaked

Moderators: Volker_P, tidd650

Posts: 1
Joined: Mon Aug 03, 2015 9:59 pm

Need help 84 DOHC 650 feels likes its running on 2 cylinders

Postby KC650AZ » Mon Aug 03, 2015 10:14 pm

I have a 1984 Honda CB650 Nighthawk.

It has:
1. Pod filters,

2. 4-1 kerker exhaust

3 79k needles

4. 122 main jets with 2 shims

5. 35 slows

6. Good compression 135 - 140

7. New/used CDI box, wires and coils.

8. coils tested fine at 3.0 ohms

9. New battery

I just got the bike running but it's weak and feels likes its running on 2 cylinders

It burns a LOT of gas...It spits gas out of carbs and backfires, very hard to first start.

It has new plugs and once running I noticed that cylinders 4 and 3 are very hot but the plugs are normal ash color.

Cylinders 1 and 2 are much cooler and plugs look new and white.

For instance I checked header temps for 4 and 3 and they are each 400 degrees hotter than cylinders 1 and 2.

I am getting spark when tested on cylinder 1

I cleaned the carbs twice

What is wrong with this bike I can't figure out why its running like garbage. Which cylinders are actual working correct? The cold ones or the hot ones?
33dede.jpg (118.37 KiB) Viewed 17221 times

Return to “Technical Discussion”

Who is online

Users browsing this forum: No registered users and 25 guests