Honda CB450 Ep 8 - Bench synhronising Keihin carburettor

Рет қаралды 1,021

2 жыл бұрын

Welcome to the vlog! In this episode I’m bench synchronising the CB450 carbs to have them ready to place on the finished bike. I go through the float heights, air mixture screw and the opening of the throttle butterfly which is managed by the idle screw on each carb.
The float height is set to 20mm as outlined in the Haynes manual for this bike but I’ll be filling the carbs with fuel in the vice to check for overflow and leakages before having them on the bike. Adjusting the floats with the carbs on the bike is a nightmare!
The air mixture screws are set to 1 1/2 turns out on each carb as a starting point, these will need to be adjusted to suit the mixture once the bike is running. Either with a colourtune or idle drop.
Finally, the throttle butterfly openings I’ve synchronised with guitar string to get them to open at the same time. Again, final adjustment of this will be done with the bike running.
I hope you find it useful!

Пікірлер: 4

@CCitis 2 жыл бұрын

Love an update on how your CB is going

@ratmotors903 2 жыл бұрын

Thanks! Picked up the frame and bits and bobs from the powder coaters over the weekend so it’s looking like being all ready to bolt back together.

@trucktruck8016 Жыл бұрын

you stated that your 450 is or is going to run pod air filters , and you have pattern exhausts ? also the stock main jets are 125's ? . Think you will find stock for your late model 450 (disc brake ) stock jets are 130's , also the stock air filter/airbox set up does flow a good amount of air , the exhausts tend to be the restriction , especially if carboned up , with less restrictive air filters and exhaust you would normally need to go 20% larger in jet size , not smaller . I suspect you will run weak above 3-4k rpm with 120's .

@ratmotors903 Жыл бұрын

Hi, thanks for your feedback. Honestly, I ended up in a total confusion of settings, jet sizes, filter densities, exhausts, manuals and ended up resting on this combination. The exhausts are brand new so no carbon deposits as yet. I had stutters at 3-4 on tachometer so upped the jet sizes slowly. Ended up with 145 and found it impossible to idle. Wet plugs too. Dropped it back down. Had big issues with feeling which I then thought could explain the stuttering at higher rpms. There’s a lot of conflicting info. Clymer, Haynes and Honda service manual all state different jet sizes. 125 or 130. For mums again are a little conflicting. I’ve gone with the 125s for now and will assess the situation as I get going. I dare say I’ll end up somewhere around 130/135. I’d really love to source some original air boxes! Thanks for your input.