Somethings not right
1974 Honda CB450 DOHC
ALRIGHT BACK TO BASICS...There are only so many things an engine needs to run, spark, compression, fuel, and timing.
Both carburetors have been rebuilt correctly and the correct amount of gas is flowing into the cylinders.
Both cylinders have about 150+ compression.
Both spark plugs are firing.
The cam and crank have been timed together correctly after rebuilding my cylinder head, timing for the ignition is timed correctly to the compression stroke for both cylinders.
The bike wont even fire up while I'm spraying starting fluid direct through the carbs (choked or not).
Is there something obvious I am missing?? WHY wont this bike start!?
thankyou all who respond i need as much insight as possible.
Last edited by ckemps; 06-12-2019 at 07:41 AM.
Are you using the kick start, or electric? If electric, the Voltage may be sagging too low to get a strong enough spark, so try using a booster battery; if you jump to a car or truck do NOT start that vehicle's engine!
Mine is a mostly 1970 CB450K3
The cam on the advancer could be 180 degees off
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What reference are you using to determine compression stroke for a cylinder?
Has the rotor been pulled and re-installed?
Please feel free to phone to complete this dialog.......
Last edited by 66Sprint; 06-12-2019 at 03:22 AM.
"I have a mind like a steel trap.....Old and rusty, of antiquated design, and hard to get stuff back out of...."
Contact info: E-mail; [email protected] Phone; 540-525-5199
My question... was it EVER running???
Then... what was done to make it not run?
"Yes, my hands and nails have grease stains. I ride vintage!"
You mentioned "The cam and crank have been timed together correctly after rebuilding my cylinder head" and "I've pulled off the cam head cover" - are we talking about a DOHC CB450, or the later SOHC CB450? big difference in ignition and cam timing between the two
I ask because when we don't have an Introduction, it takes longer for us to fully understand the new member and what bike he has...