Ten ways to Sunday....
That's how many attempts I have made to get my 1988 CR250 to pull through the midrange. It is friggin' hopeless.
Seriously, I have done everything that I can think of but nothing changes that bloody midrange problem?
I have bottom end and topend but "where's the beef"?
Here is a brief list:
1) New piston, rings, topend gasket kit (Athena Graphite Coated)
2) Uncoked power valves and got those working
3) Replaced the ignition system with a newer one(Including CDI module)
4) Replaced the reeds
5) Bought a jet kit with everything from 160-200 main jets and went from 170 through to 190 with no change to the midrange (stock is 185)
6) Check for crankcase pressurization by inserting tube into bottle of water (no bubbles) and no coolant in oil.
7) Double-checked HPP to make sure they were opening. They were!
8) Replaced cylinder head with one that was completely in spec.
9) Tried a hotter plug
10) Pulled the carb off so many times, I lost count.
11) Air filter is clean as a whistle
12) Plug is new (well, one of about a dozen new ones that I have used to test.
13) Compression is excellent (starts on 1 or 2 kicks) and it even idles pretty darn good.
14) Has a Pro-Circuit pipe.
15) Mixing at 32:1 at sea level using Honda Synthetic (Prolube I think it is called?).
16) Checked timing and it is dead on
17) Prayed to the Honda god and I think I felt something hit me on the forehead (damn seagulls)
It feels like I am chasing my tail. Messing with the carb in an attempt to fix something else that is happening.
I am convinced that this is NOT a carb problem. There is absolutely no way that I could make so many changes that had zero effect on the problem.
What about that HPP system? When are those valves supposed to open? I have read that it takes a pretty high RPM to get the centrifugal action happening. Mine open when I get on the throttle but the bike isn't screaming or anything.
Can I remove the valves temporarily to see if that may be the issue? Or at least get them to stay open or closed?
Bike revs smooth as silk on the stand but doesn't do squat in the midrange when moving. It just farts and sputters on and on.
The bike WILL foul the plug after you ride it for about an hour or so ----yet will bong, bong, bong on return to idle after and good blast like it is running lean and suffering detonation?
Its a friggin' enigma!!
I even took it to a reputable shop and they couldn't figure it out either?
Surely gawd, someone out there has experienced something similar to this?
This bike is almost a parts bike now as I am nearly at the end of my rope with it. I hate to give up on something because I can't figure it out but I can tune my sons KX65 to within' an inch of its life yet can't even go for a ride with him because of this piece of s@#t!!
This is the VERY last time this bike will get mentioned on the board. I have wasted enough time on it already.
Cheers
Bernie
:bang:
That's how many attempts I have made to get my 1988 CR250 to pull through the midrange. It is friggin' hopeless.
Seriously, I have done everything that I can think of but nothing changes that bloody midrange problem?
I have bottom end and topend but "where's the beef"?
Here is a brief list:
1) New piston, rings, topend gasket kit (Athena Graphite Coated)
2) Uncoked power valves and got those working
3) Replaced the ignition system with a newer one(Including CDI module)
4) Replaced the reeds
5) Bought a jet kit with everything from 160-200 main jets and went from 170 through to 190 with no change to the midrange (stock is 185)
6) Check for crankcase pressurization by inserting tube into bottle of water (no bubbles) and no coolant in oil.
7) Double-checked HPP to make sure they were opening. They were!
8) Replaced cylinder head with one that was completely in spec.
9) Tried a hotter plug
10) Pulled the carb off so many times, I lost count.
11) Air filter is clean as a whistle
12) Plug is new (well, one of about a dozen new ones that I have used to test.
13) Compression is excellent (starts on 1 or 2 kicks) and it even idles pretty darn good.
14) Has a Pro-Circuit pipe.
15) Mixing at 32:1 at sea level using Honda Synthetic (Prolube I think it is called?).
16) Checked timing and it is dead on
17) Prayed to the Honda god and I think I felt something hit me on the forehead (damn seagulls)
It feels like I am chasing my tail. Messing with the carb in an attempt to fix something else that is happening.
I am convinced that this is NOT a carb problem. There is absolutely no way that I could make so many changes that had zero effect on the problem.
What about that HPP system? When are those valves supposed to open? I have read that it takes a pretty high RPM to get the centrifugal action happening. Mine open when I get on the throttle but the bike isn't screaming or anything.
Can I remove the valves temporarily to see if that may be the issue? Or at least get them to stay open or closed?
Bike revs smooth as silk on the stand but doesn't do squat in the midrange when moving. It just farts and sputters on and on.
The bike WILL foul the plug after you ride it for about an hour or so ----yet will bong, bong, bong on return to idle after and good blast like it is running lean and suffering detonation?
Its a friggin' enigma!!
I even took it to a reputable shop and they couldn't figure it out either?
Surely gawd, someone out there has experienced something similar to this?
This bike is almost a parts bike now as I am nearly at the end of my rope with it. I hate to give up on something because I can't figure it out but I can tune my sons KX65 to within' an inch of its life yet can't even go for a ride with him because of this piece of s@#t!!
This is the VERY last time this bike will get mentioned on the board. I have wasted enough time on it already.
Cheers
Bernie
:bang: