bclapham
LIFETIME SPONSOR
- Nov 5, 2001
- 4,340
- 0
A couple of weeks ago, i recieved my cyclinder back from Eric Gorr with the porting to move the power to low to mid area of the power band....here goes with my report.
first impressions: quite some expoxy filling the transfer ports but the boost ports appeared to have a lot of material removed also. Only a small amount of metal removed from the intake and exhaust ports. It also looks like the base was indeed turned down and the head clearanced for the piston. The squish band looked quite wide also. All mods as expected.
During the installation the only headace was dowel went missing at some point so after getting that part all was bolted back together. nicely.
When doing the first few heat cycles i noticed how much quieter and crisper the engine felt, it also felt like it was only slightly lean, but i expect this may have been a temperature thing. The piston supplied was 0.1 mm larger than the old one so this explains why it was quieter.
Onto the track. bear with me here folks, the old top end was quite worn with some blow by past the rings, so it is difficult to give a precise comparision with the old setup but here is my best shot!
Crispness, this thing is so crisp its rediculous! even more crisp than a freshly cut iceberg lettuce! :)
Jetting, exactly the same as before, just a small amount of oil at the tip of the stinger. Ive gone from 50 to 46 on the pilot and the main is 175 (178 stock). the needle is stock (NE3J), 2nd from top. i tried to lean the needle before but it ran wierd....maybe 1/2 a clip like the new RM's? Conditions So Cal, motul 600 32:1 pump gas.
Onto the track: This thing rips, plain and simple....it was fast before but now it is incredible! There are no susprises, its totally honest in that you get exactly what you ask for.....instantly! It pulls from the bottom and keeps going. I expected it to sign off at the higher RPMs, but it contines to rev all the way, even free-er and better than before. I wonder if this is because of the lighter wiseco piston. I was worried that since the SST pipe is known to be a revver, that it would be incompatible with the low to mid porting but it appears the porting compliments the pipe by adding to the bottom without taking any thing from the top.
Is the bike easier to ride? Yes and no! the yes part is that it pulls much stronger and smoother from the bottom and only needs a quick dab of clutch to get into the power. It is also easier to stay in 3rd where before a downshift was needed so its easier to ride jumps in that respect. The no part is that is that now it moves to top speed a bit quicker and then keeps going, so that i overshot a few corners! :p
In all i am a very happy customer, and i recomend the work. :yeehaw:
I saw a few posts about turning yz250's into trail or woods bikes and there were some suggestions about this porting. Now the bike really feels like a balls out MX weapon, and personally i wouldnt want to take it anyware near fixed objects such as trees! Before it was fast, now it still goes fast, but it goes faster much quicker.
my setup: 2001 YZ250, SST pipe, shorty silencer, low to mid EG porting and everything else stock. 46 pilot, NE3J 2nd clip, 175 main. I dont need to bother with the v-force or fancy reeds now!
thanks eric, you are da man! :worship: :thumb:
Bruce Clapham
first impressions: quite some expoxy filling the transfer ports but the boost ports appeared to have a lot of material removed also. Only a small amount of metal removed from the intake and exhaust ports. It also looks like the base was indeed turned down and the head clearanced for the piston. The squish band looked quite wide also. All mods as expected.
During the installation the only headace was dowel went missing at some point so after getting that part all was bolted back together. nicely.
When doing the first few heat cycles i noticed how much quieter and crisper the engine felt, it also felt like it was only slightly lean, but i expect this may have been a temperature thing. The piston supplied was 0.1 mm larger than the old one so this explains why it was quieter.
Onto the track. bear with me here folks, the old top end was quite worn with some blow by past the rings, so it is difficult to give a precise comparision with the old setup but here is my best shot!
Crispness, this thing is so crisp its rediculous! even more crisp than a freshly cut iceberg lettuce! :)
Jetting, exactly the same as before, just a small amount of oil at the tip of the stinger. Ive gone from 50 to 46 on the pilot and the main is 175 (178 stock). the needle is stock (NE3J), 2nd from top. i tried to lean the needle before but it ran wierd....maybe 1/2 a clip like the new RM's? Conditions So Cal, motul 600 32:1 pump gas.
Onto the track: This thing rips, plain and simple....it was fast before but now it is incredible! There are no susprises, its totally honest in that you get exactly what you ask for.....instantly! It pulls from the bottom and keeps going. I expected it to sign off at the higher RPMs, but it contines to rev all the way, even free-er and better than before. I wonder if this is because of the lighter wiseco piston. I was worried that since the SST pipe is known to be a revver, that it would be incompatible with the low to mid porting but it appears the porting compliments the pipe by adding to the bottom without taking any thing from the top.
Is the bike easier to ride? Yes and no! the yes part is that it pulls much stronger and smoother from the bottom and only needs a quick dab of clutch to get into the power. It is also easier to stay in 3rd where before a downshift was needed so its easier to ride jumps in that respect. The no part is that is that now it moves to top speed a bit quicker and then keeps going, so that i overshot a few corners! :p
In all i am a very happy customer, and i recomend the work. :yeehaw:
I saw a few posts about turning yz250's into trail or woods bikes and there were some suggestions about this porting. Now the bike really feels like a balls out MX weapon, and personally i wouldnt want to take it anyware near fixed objects such as trees! Before it was fast, now it still goes fast, but it goes faster much quicker.
my setup: 2001 YZ250, SST pipe, shorty silencer, low to mid EG porting and everything else stock. 46 pilot, NE3J 2nd clip, 175 main. I dont need to bother with the v-force or fancy reeds now!
thanks eric, you are da man! :worship: :thumb:
Bruce Clapham
