Mychron 5s big rpm drops

BulletRacer008

BulletRacer008

Member
Is anyone having any issue with abnormal rpm drops on clones that are anywhere from 2800 to 4000? Im having a hard time believing im having that big of rpm drops. I believe the tach is setup properly. Just wondering if anyone has had this problem and how people have fixed the issue?

Thanks,
- Dylan
 
BulletRacer008 said:
Is anyone having any issue with abnormal rpm drops on clones that are anywhere from 2800 to 4000? Im having a hard time believing im having that big of rpm drops. I believe the tach is setup properly. Just wondering if anyone has had this problem and how people have fixed the issue?

Thanks,
- Dylan
Click to expand...
Every weekend. We don't do clones but i've got a 4 on my younger sons car that runs in the back of the A most weeks and sometimes he doesn't make it out of the B and it shows 1500ish drops. Older son racing in the same exact class at the same exact time has a 5 and it shows the range that you mention and hes running in the top 5 weekly.
 
How do you have the tach wire routed? If it’s between two pieces of metal it will show erratic drops or if the wire is nicked somewhere. Wrapping your tach wire improperly will also cause erratic drops.
 
racinnut15xm said:
Every weekend. We don't do clones but i've got a 4 on my younger sons car that runs in the back of the A most weeks and sometimes he doesn't make it out of the B and it shows 1500ish drops. Older son racing in the same exact class at the same exact time has a 5 and it shows the range that you mention and hes running in the top 5 weekly.
Click to expand...
Have you found any way to resolve this issue?
 
TGRRacing32 said:
How do you have the tach wire routed? If it’s between two pieces of metal it will show erratic drops or if the wire is nicked somewhere. Wrapping your tach wire improperly will also cause erratic drops.
Click to expand...
I have it ran in between the top plate and the block, and wrapped 2-3 times around spark plug wire. The tach lead is not bare anywhere.
 
BulletRacer008 said:
Is anyone having any issue with abnormal rpm drops on clones that are anywhere from 2800 to 4000? Im having a hard time believing im having that big of rpm drops. I believe the tach is setup properly. Just wondering if anyone has had this problem and how people have fixed the issue?

Thanks,
- Dylan
Click to expand...
I think i remember something about how many wraps the plug wire has but i havent messed with it. I know its wrong. Was actually thinking about putting the old 4 back on for the next weekend
 
BulletRacer008 said:
I have it ran in between the top plate and the block, and wrapped 2-3 times around spark plug wire. The tach lead is not bare anywhere.
Click to expand...
Under the top plate . Puts it in close proximity too the coil and kill wire .

Another wrap around the plug wire could help .
 
BulletRacer008 said:
I have it ran in between the top plate and the block, and wrapped 2-3 times around spark plug wire. The tach lead is not bare anywhere.
Click to expand...
I had one being weird last year reading crazy rpms, I ended up replacing the wire and the problem went away. I had it wrapped right and looked it over good and didn't notice anything. I've heard of people hooking them up straight to the coil lead that hangs by the kill switch

_Dean_
 
Usually if you run the wires together it will effect it, try separating and running them all alone. Dont put them all in the same polyloom
 
I'm not sure about the 5s but I hooked my 5 right to the kill switch wire and it works fine. People say "sometimes it works, some times it doesn't" I don't know why it would work on some engines and not others unless the "doesn't people" are hooking to the ground side of the switch. You have to hook to the hot side.
 
Last edited:
You must log in or register to reply here.
Back
Top