Ftz does good work on Honda 250s as well. A cheap combo that I've personally used is a trx engine with an Atc cylinder, piston, and spacer plate.
my buddy had the atc cylinder that had been ported by FTZ but when he got the cylinder it had been resleeved so we didn't use it, all the timing was back to stock. That thing was opened up big time
as far as the boyesen ports and ex, the new sleeve was blocking port area on the transfers and exhaust
Any competent porter should be able to port match the new sleeve to the FTZ cylinder for a really good price. It's not like a full on port job, just a quick match up and chamfer.
Any good sleeve job should include the port matching. Somone just slammed a stock sleeve into it. Bad move. Now they dont know the correct port dimensions or port angles for that setup. Ya it can be blended out but, you better have knowledge of the timing and duration they need to be.
yeah that's what I was referring too, I didn't no the port timing, the exhaust was covered by atleast 3mm of sleeve, they did port match the sides of the ex port but not upper.. so who knows what the exhaust duration was

My buddy got the cylinder with his 250r when he bought it and the kid said "NAPA" machine shop resleeved. ive heard bad things about the napa machine shop in my town lol
Be glad to help with any questions you have just shoot a PM. Looks like that frame has some nasty repairs. I would check that swing arm for cracks.
the ftz cylinder i used made 49whp with factory rechambered head, fmf pipe (atc), esr reeds, and pwk 39. nothing fancy but enough to blow sand in the face of many lt250r's.
Here's some cylinders laying around from back when...

Etched under front left cyl

Etched under front middle cyl

Etched under front right cyl, chrome bore 250cc



I'm not looking to get rid of anything, thanks
dezsled, what one of them cylinders performed best in your opinion??
Back row, middle cylinder. Looks like it's pretty new/nos
Is that a cylinder off an ATAC equipped bike?
I only have ridden the chrome bore cyl. It revved easier from what I recall, I never have ran the others. The middle rear is a brand new '87 cyl no not a atac chuckie sorry to say that would be nice to have. The one is for class 25 at riverside raceway, type III low end from what I was told. Here's the various chambered heads
I have a friend with a 350ct cylinder set up(unkown porting setup ) , ive been wanting to see how well my lt will hang with it.. ive ran it on the 500 and creamed it easy but I wana try 250, he will win the distance but I gota say this Carl(iceracer) 250 I think will make a good contender lol
I have since sold my friend and quadzilla and currently only one Hondas. 3 trx250r's.
Your Aarms are not stock. They look to be LS parts. Besides the arms, tires, and Aarm skid plates your quad looks stock. If you got it cheap then I say its a great score. Head over to trx250r.org lots of good guys with lots of information to be shared. Just the same as here.
I know this is a Suzuki site and everyone has a uncles cousin that has one that runs like an ape. Some wrong info was said here. 85/86 are short rod engines. 87-89 are long rod engines. 85/86 cylinders can be used on 87-on cylinders but a spacer plate will need to be used. Mixing and matching of all years are possible just as long the correct combination is used. Same goes for bottom end parts. As far as frames and suspension.
Go check out that web site. Someone is always selling you "need" lol