Brand new K90 for sale. - SOLD.

[Wasted wages]

Thanks for that info Jeff !!

I am thinking my fuel delivery will all need to be revamped... brass tubes in the tanks, LARGE fuel line, 3rd channel valve, spray bar..
I bet this motor gulps fuel !!

 

[Wasted wages]

I ran them for years and officially ran 113 mph with a twin in 2009 at Huntsville on 50% nitro. Boat was radared 118 at the end of the straights. I was fighting the boat and had a lot of issues that kept me from setting a record that weekend. Every stock engine I measured was 180 ex, 120 boost/transfers. 1cc head 7.7 :1 cr. A .030” shim makes the exhaust 190 with 130 boost and transfers. Make you a bigger spraybar for the carb, not for breaking but for I.D. size. It will help with going lean on the top end. If you only run a .085-.095” spray bar then run a stinger size of .430-.450 . Jeff Lutz

Jeff, what size props were you running?

Terry mentioned that he pulled a full bladed cupped up H50 with one of his ??

 

[Wasted wages]

They are great engines. I did the sleeve porting on this motor for the guy I got them from. I am not sure but they may have been sent to me first by Al and I prep the sleeve and sent them on to where they were going. These motors had such a small tapper on the sleeve that they would stick when trying to break them in. So I came up with that idea to cool the piston on the exhaust side. When the piston goes down for a intake charge cool fuel is pushed up the outside of the sleeve and onto the exhaust side of the piston at the top of it. I always ran 50% to 60% with 22% Klotz oil and still do.
I do have three more of these motors that are new and for sell from the same guy. They have been on his shelve for many years. Same price of $500.00 and I will ship anywhere in the states.

Mark... you have a PM.

 

[LarryBeals]

Tom Prezfield ran this engin X 2 in a twin spraybars broke off two out of three engins

 

[Jeff Lutz]

It’s a good idea to change the wrist pin. They break. I believe a OPS .80 pin replaces it, or a Rossi .90 as the K90 is based off a Rossi .90. I started reaming them up a tick and installing a CMB 67/80 wrist pin or Vac .91 pin as it is the same.

 

[Al Hobbs]

The early K90 engines brought into the USA had some breaking wrist pin issues. Kalistratov then made a different wrist pin, solid in the middle and open on both ends. No more broken wrist pins. Take a look to see which wrist pin you have. It is the same wrist pin as on the K80.

 

[bermudadude]

get a mac 84 carb and mod it or carb made similar same bore (or a couple thou more) lower that clearance (better yet a head with smaller volume) get that timing up over 190 throw some 50% (with less than 20% oil) down its gullet ,strap on a 90 muck pipe ,a stupid cupped h50 or a stupider cupped 1667 or similar and strap on ur adult diaper lol
o ya and yup that as well as any high performance 90 -needs .125 or close spray-bar
dang now i made myself sad ,i want piston/liners for my old k90's