Honda CB450 K5 Cafe Racer.. ish

Are those EMGO pods? If so, throw them in the trash, or do some searching for the technique to mod them so they don't restrict airflow.
 
Floats with fuel in them must be replaced. I would also fit new OEM air filter and throw away the pods. Those carbs do not work well with pods - even "good ones".

Float height is a bit tricky to set. 99% of the pictures show the carb upside down, but that is not how to do it. The carb has to be tilted so that the float just starts to rest on the needle.
https://www.fix.com/blog/motorcycle-carburetor-float-height-adjustment/

A better way is to set FUEL level which should be 2-4mm below the gasket surface.
http://xjbikes.com/forums/threads/wet-set-can-somebody-check-my-work.44934/
http://69.46.28.106/forum/3-carburetor/503227-wet-float-level-for-900
 
I made a float height tool like this from an old card to adjust the heights on the bike.

FloatGauge.jpg


Turn off gas
Remove bowl
Hold float at proper height with tool (at lowest point on float)
Turn on gas
Adjust float tab so that gas just starts to leak out if you lower the float even slightly (you will have to turn the gas on and off to do this)

It is a little messy so be prepared for cleanup, and keep a fire extinguisher handy.

As Teazer said, if there is any fluid in the float, they won't work correctly. There must also be a crack somewhere and more will get in.


As for air filters, if you don't have the stock airbox, you can try these UNI filters. My bike has been running OK with them.
Uni_foam_air_filter_set_nu_4001_cb350_cl350_cb450_cl450_cb500_17210_310_000_17311_346_671_17211_375_000_144001_1__47409.1371582659.750.750.jpg

http://4into1.com/uni-foam-air-filter-pod-set-cb350-cb450-cb500/



end of line
 
It as pods and aftermarket mufflers.
20 years ago (when it worked fine) it had no air filters. Only two horn shaped tubes with a wire mesh, so maybe these pods are restricting air flow.
After I do the valve adjustment and the new points I'll try on those "horns" and see if it runs better.

I'm probably going to order two carb rebuild kits with floats as I'm sure that float that's leaking must have some kind of influence.

For now I'm sure the valve adjustment and points are the most important thing.
I'm pretty sure one cylinder is misfiring.

I've got a video but I'm not sure it's noticeable
 
Yesterday i did the valve adjustment and replaced points.
Also fitted all new internals to the carbs. New throttle cable and clutch cable.

The valves had way too much gap. Adjusted the best i could and it really does less valvetrain noise.

Checked the timing advancer and it looks perfectly functional. Decided not to remove it.
Fitted new points and they were a bitch to adjust... but only because i'm a dumbass and didn't (initially) do it like the tutorial.

This one. <iframe width="560" height="315" src="https://www.youtube.com/embed/nDvghJiJGFc" frameborder="0" allowfullscreen></iframe>

When did it on the compression stroke it worked. They are pretty much bang on.

The carbs were rebuilt with mostly all new internals and then adjusted the float using Flugtechnik's tool.

The new cables also made a difference. Clutch travel is much smoother and hopefully the throttle is more even in both carbs now.



So i took it for it's first ride

First drive around the block and it spewed oil from the exhaust on to the engine and my legs. Tightened both exhausts (which were not properly tightened) and it practically stopped.

Should there even be any oil going to the exhaust?

A continuous flow of smoke comes out of the valve cover breather tube..

Sometimes it idles at 1200rpm or a bit higher, but other times it idles at 3200rpm. What can it be? Air going in?

At first i rode it without filters and then put those cheap air filters. No difference. Also the choke only stalls the engine. Never runs with it closed.

While running it revs nicely (but not perfectly) until 6/7000 rpm. Doesn't pass that.


But not all are bad news.. After many pitstops at my garage i finally took it for a long drive. Rode it for around 15 miles and it didn't leave me stranded.

Overall i'm happy
 
This is the carb rebuild kit i got, but i didn't use any of those two O-rings because i couldn't find where they go.

What am i missing?

 
And this is a video made before these latest updates. It ran, but didn't rev higher than 3/4000 rpm

https://www.youtube.com/watch?v=2_OXrRUq0kI
 
There should be no oil to the exhaust. If so you may have worn rings. Check compression and if it's low add a tbsp of oil in the plug hole and check again. If it increased significantly your rings are worn.

High/inconsistent idle will most likely be caused by out of sync carbs or a vacuum leak allowing more air in. You can spray wd40 around the carb boots on carb and engine side while bike is running, if RPMs surge you have a vacuum leak.

If you have white "smoke" coming out of the breather that is normal, it's actually water vapor "boiling" out of the oil, and is normal. Usually it's not noticed because the breather is rerouted to the stock airbox.


Sent from my iPhone using DO THE TON
 
Thanks!

What may be the consequences of worn rings? From what I remember it's not a big deal. Just loss of power and oil consumption.
Am I right? These engines are new to me.

What about those O-rings? Where are they supposed to go? That may be my leak..
 
bezugo said:
Thanks!

What may be the consequences of worn rings? From what I remember it's not a big deal. Just loss of power and oil consumption.
Am I right? These engines are new to me.

What about those O-rings? Where are they supposed to go? That may be my leak..

The small o-rings look like they go on the air/fuel mixture screws. Check the Honda parts fiche for your model for the order of spring/gasket on the mixture screw - you can go to any Honda dealers site and look up your model in the OEM parts finder. I use my old local dealer Bettencourts.com

It depends on how worn your rings are, but that's what they cause. The more out of spec they are the more noticeable the effects will be. Checking compression will help narrow it down.


Sent from my iPhone using DO THE TON
 
Thanks!

What may be the consequences of worn rings? From what I remember it's not a big deal. Just loss of power and oil consumption.
Am I right? These engines are new to me.

What about those O-rings? Where are they supposed to go? That may be my leak..
 
First, the carbs:

You replaced all of those things in the pic except the o-rings?

The larger of the o-rings goes on the bowl drain screw.

The smaller of the o-rings goes on the air/fuel mixture screw. You also have to have the spring and washer on there in the correct order. First you put the spring on, then the washer, then the o-ring.


As for the oil from the exhaust:

There should be abolutely no oil in your exhaust. If there is you have a problem. Was the oil coming out where the exhaust attaches to the cylinder head? Are you sure it wasn't coming out from between the cylinder head and cylinders near the exhaust?
 
Oops! Guess I didn't do everything right.
There was no washer or o-ring between the spring and the mixture screw before, so I didn't know they should be there.

I didn't use any washer other than the one that goes with the float valve and didn't use any O-ring.
The main jet was changed by the one with the same number (size?) 145.

That may very well be my air leak.

The leak is almost 100% sure from where the exhaust attaches to the cylinder head, but tomorrow I will make sure.
What are the consequences of both cases? Solutions?
 
Take a look at the parts diagram and make sure the carbs are assembled correctly. Did you use all of the parts in the rebuild kits?

http://www.partzilla.com/parts/search/Honda/Motorcycle/Models+with+no+year/CB450K5+A/CARBURETOR/parts.html


The smallest washer goes on the air/mixture screw, one goes under the float valve fitting and the last goes on the silver plug that you can unscrew on the bottom of the carb.


ZJhqqqoQZz89L-Sniy6o6l9tLX8D7LRpmgXe-ImW1ejnxYGYwrcuqYXkVMQFkbS6npVfSjSgD_pbIe6slpooSbcaPcH808eQG1q-cAxKK9ph1TfOaN2UqDXcDtEnySUTmcuIaFTsg5lnhbyafsU_rSHGa-irf32oAuGB6ZHhclbPEKjkt0048G--wNbkL7l5o9IqJLDxuUdof8Nf2-yk2SqAgSlWkkpqP6G2_XI-BYUTGRKby9o_wzZkVy3KS6A4awdKaCbFk32NBrlrcUR484dBP93aJt68jLjcY14AF6ALcrQzenGIX6WIcrw12YGbUnHGeBeFfLaQbipayl95ksKDGqZzIABj_79ftObAeGuriOCh2MbWnIUiy0Ha7FgzLyHezz60EXedtrdptVHTb1lcJLQJzBzaYLC0QRmXysTx9SLWaefl6idD9OXLEWy4Chj3Zp0WAnDRzvFj04kuz0cwDtSpTjyPgf1JkcZTa20ttkLaj-g4sAr1F_8AEfy7acS4YawMU_uSkwdZ9KGhyxjSfFgRq2g-03E91FO0M6BBKSbwlfdquW1tv0OxqbLfQtO6wTAZLQfh6H-GXkER8iFxdq0n62o=w1229-h921-no


Make sure the old washer and o-ring are not still stuck down in the hole.


pqwMVF-pKsISvs27m9fSFjh5sSIsInDcT4NQ4htycXKmREhy1PK_Hvuln2hdQ_C55H5f7IZpxMZIKauUmnZwk_rGM-K9RAheN5HpQIDjhv4PsQWd2pym2kO0WwO09fYBRdV819DpMfY7fNsn1l5xL4ftzTzaF7-zVatj2YNGKDq-XzZYh0n_2cNTlXQMn0_Y_fB2U0NeEKFALbYFtpZmCP9OK16FJ_16_CttF_YWIDaDcBnnLZvVwq4u4CUf0f9nViNDRkFpVetGrijmGjwRuFUS70ud4G08J8ICB6Ev9Q0gCK0bGiKaEGnofPLsHqVry7VWOhrAqhVmA720MPIDhPNBHsdczdXDpy4IToknQBZ5Rx2xhR2kkca7APL7xjYyAbrljDG1MykOl6ArCMhr9cKbxykPi4ZdkLO0V5Y4ugKFnyhk_7Si-4rfHjGI8aBRXH5Dht_wXE7Mq6qBPsCjjR1s72p5f02qD6OxPyv2Ce9Vz5MMjHBZRf-cj7clN8A6fpaPLFnMa-2ALTmSYV24WdsmZGq6cPsYv6d8SuppCONLo8tN_ibmDzgdh7KZU-rLV6MVp27t6l9PrvMn8f9QfnGLEuY3Cqg=w1229-h921-no



I just rebuilt my carbs a few days ago. Here are all the parts. Should be the same as yours.

vZn7fmsO5_Uuf8h2PlDNkyghq_aVBIEIXp0XBCL4FNbyQIBWUt-FV2IJUuvPsjjYjBKyus75fWyDODVnPOZaFuMjOAqHsIF99yrEQtGhdgaQqZSstw0Y8jVdSsgwd40PAAPLjzUKmw9OPslVkJ6lTT0DLC-sJebSnF3jS4lx8EjPxRY2SYAFmwYHzsmAzHyAAvH73oHg1KhIdp11yzqcdUBUHmEfwbeBAMFr69bm5sMzAOP8tSZ3kNm02V7u6xgqvMlfEQE-4Bofk2jQ9-pLVNI19S_pWKXpb_jIFeMqimGkFFLQFW2YMAeDjUX647s5Rr8kvxcGIrz91_8WGgKsBCPH18U0Ld5_QBpoqfw5KZ2VHB9UWMMBIwxKhnHdBGLm2XzwTRTmBGNfmCc8PPW0B4ygR_9k7Pet5LA08NJO0mrc4Yns0kU76FMuQKaHQel8Pe5Heg_k1AcUg5YjDirIvMC_7ZEgVQqGGLkPGHqvnMX5WvtorIeUCimPiHsKypBanKLHE-NNPOeNlt338A7SaA_5uoW4MKm23aAdGuu_r1dxgHPCEx4lVOM5Zl1w_oOwHouL84uWiALWMasmw8CxFwoNMrRqltQ=w1396-h1047-no
 
I didn't use all the parts. The o-rings and washers were left out because I didn't know where they went. Only used one washer on the float valve assembly.

I'm guessing the o-ring and washer are still in the hole... If so, they're probably not doing their job that well.. being 44 years old.
 
The washers usually come out with the spring but the o-rings can tend to be sticky in there. I use a set of picks from harbor freight they cost about $3 and are pretty useful when it comes to cleaning small parts.
 
If oil is coming out of one of the exhaust ports, there are three possibilities I can think of.

1) The piston rings in that cylinder are very worn or broken and are allowing oil past and into the combustion chamber and is then getting spit out. There must be a lot if it is not getting burned.

2) You have a very leaky valve guide/valve seal. It is letting oil leak down into the combustion chamber. There must be a lot if it is not getting burned.

3) Your cylinder head is cracked around the exhaust port somewhere.


Are you sure it is running on both cylinders? Are both exhaust pipes getting equally hot? It will continue to run on one cylinder, just not well.
 
I will remain optimistic and hope for just worn rings. Wouldn't broken rings make a bad noise?

I read somewhere that it could be possible that the air/fuel mixture is too rich (which would explain why closing the choke only stalls the engine) and it could be spewing unburnt fuel mixed with some oil.

It's just that for all I've read, i still don't get why it's stalling when i close the choke. It should help with cold starts right?
 
It is definitely running on both cylinders with similar compression (tested with hand in front of muffler).
Temperature i don't know. I'm sure both will burn my hand.
 
You need a compression tester to test compression. The exhaust won't tell ya squat. You can pick one up at any auto parts store for around $25, it's a great tool to have if you're working on vintage bikes.

Choke is for cold starting only as it enriches the pilot circuit. The bike should stall after running choked for a bit, that's normal.


Sent from my iPhone using DO THE TON
 
Back
Top Bottom