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redcoat wrote:If I attach a clear tube to the float chamber drain, can i get an accurate result while the carbs are still on the bike? I was thinking of the clear tube from each carb, putting the bike on the centre stand, and taping them to the fuel tank in a big u.

My only fear is that the bike sits slightly nose down on the centre stand, and hence, the fuel may show this incline? Am I right?

Or should I do a bench test?

And if they are wrong, then what? The floats are not adjustable...

Damn I wish i had an old Amal monobloc carb on it...

All good questions, which is why I referred to the manual. On some bikes you can check the float bowl level with the carbs on the bike and the bike on its wheels (i.e. someone holding it level). Others not. I haven't touched a Honda 450 in decades, so I wouldn't venture to guess. I would also hope that the shop manual would have some suggestions if the level were off. Even if the arms aren't adjustable, there has to be some way to fix an abnormally high level (different floats?).

Since you seemed to have covered everything else, I just thought I'd throw the float bowl test out there. I thought at least if you could find the source of the problem, you'd be halfway there. With poor MPG, smoke and wet plugs, something has to be creating an overly rich condition.

redcoat wrote:You know, it might be helpful to read the posts I have made on the subject, then you'd know I've given you your answers about 4 times thusfar in this thread.

The carbs were synched last June after the rebuilt carbs went back on.

Dude, I'm trying to be helpfull, If you don't want it, its no big deal to me.. my bike is running fine.......

That being said,

1. I wouldn't trust a dealer carb sync on an older bike at all.
2. When I get to a problem I can solve... I start at the beginning. Put all the parts back, do simple plug chops and do what they tell you


It sounds like you are right.. your running rich.... I'd start adjusting the pilot jets to eliminate the rich condition on each carb body until they are all looking good. It also would NOT HURT to put a manometer on those carbs and verify the sync.

As well... I looked at the parts diagram and it looks to me like the floats would be adjustable. But I guess if they are all plastic, it would be though... do you have any pics?

You'll remember I was getting 9.5-12.7 km/l, or 35-30mpg (Imp, not US). Fitted the new needles and seats/jets, and now get 23km/l- that's almost double the efficiency. And to think how much gas I've thrown out the exhaust pipe over the last two years...I could have had a new to me bike.

Hard to find Honda bits? David Silver Spares in the UK has everything from '53 on. I wasted weeks trying to find the bits in the US. Absolutely fruitless exercise.

Doesn't need choke to start.

Back fires a bit on deaccelaration on the freeway.

That is a HUGE indication that you are running rich. If you can start your bike without choking it, your idle circuit is running rich. Done deal. Same thing with popping on decel, could be exhaust leaks too. But, run the bike up till it's warm, then adjust your idle circuit till you have the "highest" idle. Hard to do when you have a bank of carbs, much easier on a twin. OR....buy a ColorTune!

~Gavin

Greetings Gavin.

Welcome to the forum.

If you read the post immediately before yours, you will see that the cause was both found, fixed, and a solution offered to others.

Good observation that it was running rich. You must have picked it up in the many previous posts I made in this thread.

Is it just me being a pansy, or are you just a little bit of an a$$ hole?

we have a winner....

Fire guzzi- yes, I probably am. But I'm also a guy who came here looking for some people who would give me some better feedback than "buy a new bike"- so I took great pains to give a very clear description of the problem, symptoms and work history, hoping someone would put the clues together where I had failed to. And I suppose I wrongly assumed that those offereing advice would take a little time to read what I had carefully written, and consider it.

But thank you for your nudge, I'll try to watch my words in future.