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Discussion Starter · #1 ·
Following Bill's excellent "Timing Guide" I set the timing today and managed to get both marks (left and right) perfectly inline. The bike started and idled easily BUT on a test-ride it would bog down and misfire BIG TIME when I try to accellerate beyong around 5000rpm.

I got back to the workshop and removed the tank. When I removed the air-filters I found this.....



It appears that the previous keeper "bodged" this damage rubber using lots of silicon sealant. So, I'm guessing that some of all this silicon has found its way into the carbs and may be the cause of the problems. Anyhow, I proceeded to remove the carbs themselves and after I took them off the inlet manifolds I found this.....



Grrrrrrr! :evil: What a guy! I own an ultrasonic cleaner, so I'm gonna give the carbs a good cleaning and checkover and see what difference it makes.

I also happened to notice that my battery was sparking at the positive terminal! The previous owner had fabricated a cover for the battery to prevent shorting on the seat pan (presumably), but had made it from carbon!! Well carbon is electrically conductive(!) so it wasn't exactly a great material choice :lol:
 

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It's always something with these bikes.....
Glad your timing is straightened out though.

What kind of shape are the paper elements in?
Are you determined to keep everything stock?
 

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While I'm thinking about it, you may want to check the timing with a strobe, just to make sure the advancer actually works ok.

Probably your siliconed carbs, but you never know.....
 

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MadDogMcQ said:
Elements seem okay Bill. Having a reliable, sweet running bike is more important to me than keeping it stock.

Why? Did you have something in mind?
If they're ok, I wouldn't mess with it - at least until you get it running right.
You will have to find new rubber parts for all that, might be a problem.
You have several options for replacement filter elements - foam socks, replace the paper with foam, replace the paper with new paper, etc. Lots of posts here about it.

A 450 carb won't give you a hard time about air filters (assuming it's clean and works ok).
 

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i have a set of uni foam filters off of my cb450 keihin carbs that i'm not using if you end up looking in that direction. brand new, never even oiled up. PM if they might be of interest?
 

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Hey mate you're not the only one that's PO had a silicone fetish, this is one of my Yamaha's :shock: :shock: That's just the beginning of the mess he made.

Sorry to redirect your post :lol: :lol: Looks like a carful examination of your bike is in order, but you're in very good hands with Bill leading the charge ;)

 

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Discussion Starter · #10 ·
Got my Keyster KH-0021 Kits today from NRP in Manchester. Super quick service! Went in the workshop and rebuilt the carbs. Looking forward to putting them back on, but I've got a few other jobs to do first. My front fender arrived from America too, so that's cool. And to top off a good day, I looked on eBay and found me a NOS Air Filter to replace the bodged one! :cool:
 

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Discussion Starter · #11 ·
Rather than drive to work today, I took the opportunity to take the bike instead. It would allow me to assess how sucessful my work on the carbs had been in terms of getting rid of the bad misfire and the "bogging down" under accelleration.

It's only a short journey to work, so I extended it by going out into the countryside. I needed to find some open road to stretch her legs. Once warm, the engine ticked over perfectly, but when blipping the throttle, it doesn't seem "snappy" enough. Anyway, I set off and was more than pleased to find that the bike pulled well throughout the rev-range, right up to 10k. There seemed to be a pleasing amount of power considering it's only a 450 and I knew straight away that I could live with this bike.

So overall, I'm pleased with the way that she's running. There's still some fine-tuning to be done and there's still a period of "getting to know you" ahead, but I think it's all gonna be fine.
 

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Very nice retro looking picture. That could be a candidate for the front page here, at least in my mind..


GB :mrgreen:
 

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Mac,

Sluggish throttle response on a 450 is generally due to the carbs not being synched up perfectly.

Also, 450's seem to prefer a simple static timing rather than strobe. That also helps for snappy throttle response.

Man, your "K1" is so freakin' gorgeous.........
 
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