A few 250r questions

[hondardr4life]

Ok, I am going to look at an 89 mx ready 250r this week, and I need to know some of the things to look out for on the 250. I am completely new to 250r's and 2 strokes in general, but I know a lot about 4 strokes, so I figure the 2 will just be even easier. I know obviously to look for frame cracks, but I would like to know where they are most prone to cracking, so I can take a good look. Then are there any other little things I should check for?

Assuming I buy this 250 (which I plan on as long as its in good shape), which oil is the best to mix with my gas, what octane gas should I run, I was thinking 94, and what gas to oil ratio should I run? The motor is ported and polished, has a carb, and a spacer plate, so I'm thinking its either an 86 top end on an 89 bottom end, or that it is stroked. I was probablly just going to run the Honda synthetic pre mix or w/e it is, but let me know what you guys think.

[Dave83]

Cracks/breaks-footpeg area around the swinger mounts,all motor mounts,and the steering stem mount braces are the most common areas.
Gas-you will need to do a compression check to know what octane you will need.Once compression reaches 190+ you will have to run race gas(most use someting in the 108-112 range)
Oil/pre-mix= You can start a heated debate on this topic.One guy will swear by a brand while another will swear at it.The Honda stuff is liked by alot of R owners.I use Maxima,and have used Bel-Ray HR-1 in the past.Just switched to the Max on ESR recomendation and the fact my dealer gives me a good deal.

[hondardr4life]

ok thanks. I guess I'll have to get myself a compression tester. Is there anything else I should check/ watch out for??

[hondardr4life]

What about the gas to oil ratio?

[Dave83]

Ratio depends on the oil youre using.For the Honda stuff,Maxima,Bel-Ray,etc....32:1 is what alot of peeps use.Some of the newer synthetics go from 50:1 up to 100:1.When you do the compression check,warm the motor,kill it,turn of gas,hold throttle wide open and kick until the gauge wont read any higher.
The engine cases(especially around the sprocket and across the front,below the mount bolt) are good places to check for damage/bad repairs.On the frame,I forgot,check the sub-frame where the rear latch is,another common breaking point.