Topic: CB500 Carb Rebuild kit from Cruzinimage - Review & Photos

[Puffin]

So I ordered a Carb Rebuild kit from the 'Cruzinimage' eBay vendor some time ago and I finally got round to cleaning up the Carbs on my Project Bike.  At this point I started doing some research and discovered that the general consensus is that most of the time only the gaskets and O-Rings are required and that most aftermarket jets are not worth the money... in fact the word 'Junk' came up a lot.

I thought it would be interesting to see if this is the case with this set and so I took a load of comparative photos which you might find useful if your thinking of purchasing this kit.... or not.

This is the kit as it comes.  It's $42USD plus $9 postage (to New Zealand) and arrived in about 3-4 Days.

It has everything required to rebuild 4 x Carbs and each pack comes with 3 main jets and a number of extra o-rings for the jets and fuel-line T connectors.  It includes a 100 Main jet (Standard) plus two smaller jets (a 78 and a 98).

[Puffin]

For comparison here is the replacement brass hardware against the original Keihin parts I removed.

At first glance everything appears to be identical...

[Puffin]

Emulsion Tubes close up...

Can't see any difference, holes in the right place and the same length.

Tick so far...

[Puffin]

Slow Jets close up.. again appear to be identical.  The same length and the holes are in the same places.  Marked 40 as are the originals

[Puffin]

Air Screws..

Again very very similar however very slight difference in the taper at the tip.  Not sure if this would make any difference?

The new spring was slightly longer but may be due to shortening of the original after 43 years of compression.  It seemed to make no difference when inserted.

[Puffin]

Main Jets...

The only discernible difference I could see here was a slightly different thickness in the 'ring' at the base of the jet although this is only cosmetic and has no functional purpose.

The hole sizes on the original 100 Jet and the 100 aftermarket jet seem visually the same but i have not measured this in any scientific manner yet.  i will test the hole sizes and report back.

[Puffin]

Float Valve Seat and Spring...

Identical.. Action on the springs was really good.. pushed it down about 30 times in a row and it returned with vigor each time.  I really couldn't tell the difference between the new ones and the originals

[Puffin]

... except when I put the spring in the seat... the aftermarket one sat just a tiny bit higher. 

I measured the internal depth of the seat using the plunger on my digital calipers and the aftermarket seat was around 0.35mm shallower.

I guess the implications of this is that the floats will sit slightly higher potentially putting more gas in the bowl?  If you check and adjust your float heights using the clear tube method i assume this is easily corrected?

Maybe somebody better than I might want to speculate as to the implications.. if any at all

[jonda500]

the #100 jet is exactly 1.00mm - you can compare the new ones against the originals with a 1mm drill bit -the blunt end should be a nice snug slide in fit.

[Puffin]

the #100 jet is exactly 1.00mm - you can compare the new ones against the originals with a 1mm drill bit -the blunt end should be a nice snug slide in fit.

Great tip Jonda.. I will do that and confirm.

[Puffin]

Needle...

Both needle and clip look identical upon first glance.  As this is an important component I got the calipers out and measured the needles at the base and then at 10mm intervals all the way to the tip to check the basic taper.

I decided that they were the same as far as my measuring tools and basic methodology could determine.  The exact results are in my notepad which i'll dig out later and post.

I sat the needles in the emulsion tubes and they sat at the same heights.

The aftermarket clip in the aftermarket needle was a little looser than the original but it was very minor and not to the point I would consider an issue.  I tried the original clip on the aftermarket needle and it was better. 

[Puffin]

Gaskets..

Paper Gasket looked great.  Was packaged and sealed in a separate bag.

Float Bowl Gasket was round rather than shaped.

Was really pleased with all the extra useful o-rings for the fuel line and the main jets.

[Puffin]

So in conclusion I wasn't expecting much given most comments on aftermarket kits however I was pleasantly surprised in this case and wonder whether this particular kit, for this particular bike is actually pretty good?

I guess the ultimate question is whether it's really ever worth replacing your original brass parts so long as they clean up well?

Hope this might be useful for somebody considering buying this kit.

Cheers all

[Bootsey]

Great write up.
I saw these kits recently, and was wondering the same - all their other stuff seems to be good quality.

[Deltarider]

Are there any stamped in numbers on the needle and the main jets?

It includes a 100 Main jet (Standard) plus two smaller jets (a 78 and a 92 maybe?

100 and 78 make sense, but 92? Could it be 98?

[jonda500]

I am also curious to know the needle numbers? - I have 627B and 022A carbs both with needles numbered: 272304 and would like to verify as the correct needles for the four into four exhaust pipe model, John

[Puffin]

Great write up.
I saw these kits recently, and was wondering the same - all their other stuff seems to be good quality.

I actually needed the carb boots and I bought this kit at the same time on on a whim...  The carb boots are great. 

[Puffin]

Are there any stamped in numbers on the needle and the main jets?

It includes a 100 Main jet (Standard) plus two smaller jets (a 78 and a 92 maybe?

100 and 78 make sense, but 92? Could it be 98?

Just double checked and you are correct... 78, 98 and 100 are stamped on the three jets.

The replacement needle has D26 stamped on it, the original is stamped 272304.

[Puffin]

I am also curious to know the needle numbers? - I have 627B and 022A carbs both with needles numbered: 272304 and would like to verify as the correct needles for the four into four exhaust pipe model, John

Your needle number is the same found in my 627B carbs.  I have no reason to believe this is not original.

[Deltarider]

The replacement needle has D26 stamped on it

I have no reason to believe this is not original.

But I have as D26 indicates it's a Keyster kit.

[Puffin]

The replacement needle has D26 stamped on it

I have no reason to believe this is not original.

But I have as D26 indicates it's a Keyster kit.

I was referring to the original Keihin needle being stamped 272304 but your comment about the D26 stamp on the aftermarket needle is interesting... maybe it is a Keyster kit, or least has Keyster made components.

[madmtnmotors]

FYI:

I tried the CI kits for my K8 CB750 and the rubber parts failed miserably. The later PD carbs use rubber tipped float needles. After one week of exposure to E10 (10% ethanol) fuel the float needles would no longer seal and the carbs began to overflow. Upon removing the bowls to readjust the float heights I discovered that the bowl seals were starting to swell. After freed from their grooves the bowl seals were too swollen and oversize to even try to reuse. This was my indication that the rubber bits were not alcohol resistant.

New viton tipped float needles and viton bowl gaskets solved my issues.

[Deltarider]

New viton tipped float needles and viton bowl gaskets solved my issues.

And where did you get those?

[madmtnmotors]

New viton tipped float needles and viton bowl gaskets solved my issues.

And where did you get those?

4 into 1 has the needles for $5 each:

http://4into1.com/k-l-keihin-float-needle-rubber-viton-tip-honda-cm200t-cb400t-cx500-cb550-cb750/

and the bowl gaskets for $3 each (on sale, normally $5 each):

http://4into1.com/shaped-o-ring-float-bowl-gasket-honda-cb550-cb750-1977-1978/

or set of four bowl gaskets for $11 (on sale, normally $16):

http://4into1.com/shaped-o-ring-float-bowl-gaskets-4-pack-honda-cb550-cb750-1977-1978/

and they have the "Keyster" set with four float needles and four bowl gaskets. I believe the Keyster parts may be Viton but would have to verify, since it's not mentioned in the description:

http://4into1.com/keyster-carburetor-float-bowl-gasket-float-needle-set-honda-cb550-cb750-1977-1978/


I have learned to read the descriptions carefully now. The description must indicate "Viton" or I keep looking. 4 into 1 has a set of four bowl gaskets and four float needles for $20 but nowhere in the description does it read "Viton" so I would be leery of this part:

http://4into1.com/replica-carburetor-float-bowl-gasket-float-needle-set-honda-cb550-cb750-1977-1978/


Float needles for the PD carbs can still be had from Honda, part number 16011-KCK-910, but I'll be dam!?ed if I'm going to pay $20 EACH for just the float needles...

[Puffin]

The main jet o ring is also too small in the kit..... The larger ring is the correct size from 4into1 and makes a good seal.