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View Full Version : "Viper" 250R Cylinder Head


crockett77
07-20-2006, 09:25 AM
Friend gave me an 85 LT250R Quadracer when he got divorced and promply disappeared.

Rode it for a an hour or so. And it was way faster than my 89 TRX 250R.

About a week later I took it out again. Filled the tank, mixture was oil to fuel 32:1, Super Unleaded(91) octane. Same as my TRX250R.

Upon riding the thing for about 15 minutes it seized.

The side of the cylinder has "VIPER" etched into it.

In talking to a few people I think the thing is some sort of High-Compression cylinder/head. I'm thinking it may need higher octane fuel. 100+ octane.

Can anybody let me know what the "Viper" etching is all about. And if this thing may truly need 100+ octane fuel.
250r4life
07-20-2006, 11:53 AM
vi·per (vī'pər)
n.
Any of several venomous Old World snakes of the family Viperidae, having a single pair of long, hollow fangs and a thick, heavy body. Also called adder.
A pit viper.
A venomous or supposedly venomous snake.
A person regarded as malicious or treacherous.
250r4life
07-20-2006, 11:54 AM
ps... sorry man, it popped into my head and i couldnt resist :D
matt250r21
07-20-2006, 08:34 PM
The Viper etched into the side of your cylinder is most likely the name of the company that moded your cylinder. The best way to see if your motor needs high octane fuel is to do a compression test. You will of course have to rebuild the motor first. Oh here is a good idea run av gas...NOT! Sorry, some of us must have too much time on are hands.
250r4life
07-20-2006, 11:54 PM
matthew, are you a little bitter? :devil:
ohsobad_chevy
07-21-2006, 08:20 AM
It seized up, did it make any noises before it quit, or did it literally lock up to a halt??
crockett77
07-21-2006, 09:56 AM
Answer found, or at least what I was told last night at a local repair shop.

Viper etching. It was the mark of an aftermarket shop in Southern California. They ported, pollished, sleeved, new reed cages, oversized piston .08-over and made the darn thing high compression.

This means that I needed to run 100+ octane fuel.

The good thing is that a local shop wants the cylinder and head. Says if the casting marks line up I get $500.00 for the cylinder and head, will give me a top and bottom end as well.

Apparently the owner had one back in the day and could never find one until I walked in.