Topic: CB550 big bore on ebay

[Flying J]

Anybody used one of these kits?
http://www.ebay.com/itm/Honda-CB550F-CB550K-600cc-Bigbore-Piston-Kits-with-Head-Gasket-CB550FBB-/160775419335?pt=Motorcycles_Parts_Accessories&hash=item256ef635c7&vxp=mtr

[Stev-o]

Hondaman has used the 836 kit from the same seller, said it's pretty good, just needs a little tweaking (search cheap eBay 836 kit if you haven't seen that thread)

Didn't know they were offering these, think I'll buy one or the future for when/if I blowup my 550 cafe

[Flying J]

I know member IRISHCBRACER had a set. I pmed him to see if he has any feedback. When i bought my set from Dynoman he said that he had people who had problems with them. But i would say the same thing if i was trying to sell a set of piston for 2-3X the price.

[goldarrow]

I just bought rings and gaskets set from them, the rings looks great. Gasket set needs slight tweak. Hope that helps

[Cheffish]

I just bought rings and gaskets set from them, the rings looks great. Gasket set needs slight tweak. Hope that helps

We need you to buy the pistons. And tell us how they look. I can't bring myself to spend the money for those dynoman pistons.

[RAFster122s]

Looks like it has the 3 piece oil control ring intead of the one piece design of the Henry Abe 605 (592) kit. That is a definite plus.
Would require lots of measurements of the pistons to calculate the compression ratio and clearances.

[Flying J]

Clearance should be fine, its just a flat top piston like the stock one and assuming the wrist pin to deck height is the same as stock i don't think the compression will change much. Which is to bad. If your going to big bore you may as well boost compression.

[Dimitri13]

Which is why one should get the dynoman kit. Trusted name, American cOmpny, and quality materials.

[Flying J]

I agree, and thats why i have a dynoman set. But if your doing a rebuild and not looking for tons of performance this is almost as cheap if not cheaper then a 1 size up piston set. If your not going to spend the money on the cam, ignition and other tuning work then why get a $500 set when you can get a set for $150. Thats what i want to find out. Obviously no replacement for a tried and true performance piston but a cheap alternative for the street cafe bike.

GOLDARROW what needed to be tweaked on the gasket set? I was also looking a the piston rings for a rebuild on my green bike.

[goldarrow]

Look in my thread here post #81 http://forums.sohc4.net/index.php?topic=106490.75

Keep in mind that mine is stock size

I just got my head torqued down, will post pic of gasket edge sticking out tomorrow.

[Flying J]

Thanks goldarrow. I will read through that whole thing when its not so late. Thats basically what i want to do to my 75. It leaks oil from the cylinders. Besides that the motor seems fine so i would like to do new gaskets and piston rings.

[cb550choppa]

im kinda interested in this set maybe ill pick one up and do it this winter as my head gaskets leaking again

[Flying J]

Just some info for people who have not done a big bore and are tempted by the low price. In my experience boring the cylinders for this size piston is going to cost more then the piston set itself.
One shop i used charge 100 per hole. The other shop is 80 a hole.

[Cheffish]

Just some info for people who have not done a big bore and are tempted by the low price. In my experience boring the cylinders for this size piston is going to cost more then the piston set itself.
One shop i used charge 100 per hole. The other shop is 80 a hole.

That really is the reason why I don't wanna spring for those DP pistons. Then my motor would cost more than I could justify. On the other hand, like you said you may as well go high compression. And you can't run a high lift cam with these flat tops.

[goldarrow]

Not meant to go off the topic but I saw gaskets and rings set in the big bore kit and thought I would chime in so other people are aware.

This is stock gaskets from same seller after assembled. Oil feed holes need to be trimmed a little to make sure o-rings on both sides sit flush in the holes.

[LesterPiglet]

Are the insides ok? If the outside is that bad how did they manage to do better on the inside?

[goldarrow]

Are the insides ok? If the outside is that bad how did they manage to do better on the inside?

The inside holes for pistons and dowels were spot on, just the outside edges were a bit too big, and oil feed holes were a bit off centered, Minor tweak.

[LesterPiglet]

Are you going to trim them? I gave it a go once. Don't use a hobby knife, it cuts the metal/paint so easily.

[IRISHCBRACER]

I bought a set although I haven't started my engine build yet, the motor is torn down and awaiting soda blasting before I send it out for machining.  Before I purchase things on ebay I always read the feedback responses, lots of people have bought pistons from this vendor and all are giving great feedback.  I just looked on there and this vendor has sold 23 sets of big bore pistons for the CB550's to date.

[Scott S]

 Just wondering if anyone has finished a build and put some miles on these piston sets?