1982 CM450A running rough/bogging

[my1973vw]

I'm helping my FIL get his 450A back on the road.

The Story: he got it out of storage and got it running maybe a year ago. While it would idle all day long it would bog down/run poorly whenever he gave it gas. It would occasionally backfire as well. He discovered that the boots from the airbox to the carbs were in sad shape.
Trying to get it running he went from the airbox to pods and it was rejetted "4 sizes larger" (he had a shop do this and the details are unknown, (fast jets?slow?) unfortunately) No improvement to the running condition. It still bogs.

My FIL has more mechanical knowledge than I'll ever have so I have to trust him for what he thinks may be wrong.

He suspects that the carbs need tuned and/or rejetted. AND/OR it is a problem with the CDI box. He's a points guy so the CDI box is a mystery to him (and me as well)

He still has the airbox and I suggested that if I could find replacement box-to-carb rubbers that he swap it back to the airbox and old (assumedly stock) jets. However I cannot find any replacements for these

I have no clue if the CDI is a part of the problem or not.

Thoughts/questions/recommendations on where to start or what to do next?

 

[LongDistanceRider]

Start here with ignition diagnosis https://www.vintagehondatwins.com/f...cb-cm-400-450-automatic-trans-1978-1983.5757/
The air box boots only came with the air box, not a separate part, so replacement means finding a good replacement airbox.
Pod filters are a known nightmare. Closest jetting for using them seems to be a 90/125 combination and even then it's not great.
Sounds like there are plugged up jets and a failed accel pump in the carbs.

 

[wentwest]

Is he still trying to run it on the gas that was in the tank? If he is, stop everything and get that gas out. Make sure the tank is clean, check the gas lines, put back the old intake stuff if you have it. If it's cracked or split maybe you can smear something on it to seal it a bit, temporarily. And put back the old jets. It's just a huge pain in the butt trying to tune an engine that isn't running its stock set-up.

 

[Maraakate]

Start here with ignition diagnosis https://www.vintagehondatwins.com/f...cb-cm-400-450-automatic-trans-1978-1983.5757/
The air box boots only came with the air box, not a separate part, so replacement means finding a good replacement airbox.
Pod filters are a known nightmare. Closest jetting for using them seems to be a 90/125 combination and even then it's not great.
Sounds like there are plugged up jets and a failed accel pump in the carbs.

Ditto this. Also there are quite a few air boxes on eBay right now for $50 with the boots. Just get new boots and clamps and really clean that carb and you should be up and running. Avoid any aftermarket parts, especially float valves.