YFZ Central banner
1 - 14 of 14 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Hey guys so I just bought my first yfz 450 a couple days ago.it starts and idles great it runs fine I till it starts to get higher in the rpms then the engine changes sound and sort of gives out.i was told it had been sitting for a few years and probably just needed a carb clean.so I drained the gas and cleaned the carb but the jets weren’t really plugged so I am not sure exactly what it needs any help would be appreciated thanks.
 

·
Registered
2019 YFZ450R SE
Joined
·
47 Posts
A good friend of mine just bought a banshee and was having the same problem so we did exactly what you did and we're still having the same issue. The elevation we live at is 5318 ft and I was told by people that are familiar with carbs that the elevation could have something to do with it. I don't know much about carbs myself but I figured maybe the elevation might have something to do with the issue you're having? I'm trying to find out what jetting needs to be done for what elevation
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 ·
A good friend of mine just bought a banshee and was having the same problem so we did exactly what you did and we're still having the same issue. The elevation we live at is 5318 ft and I was told by people that are familiar with carbs that the elevation could have something to do with it. I don't know much about carbs myself but I figured maybe the elevation might have something to do with the issue you're having? I'm trying to find out what jetting needs to be done for what elevation
Ok thanks for the help that makes sense I will look in to the jetting
A good friend of mine just bought a banshee and was having the same problem so we did exactly what you did and we're still having the same issue. The elevation we live at is 5318 ft and I was told by people that are familiar with carbs that the elevation could have something to do with it. I don't know much about carbs myself but I figured maybe the elevation might have something to do with the issue you're having? I'm trying to find out what jetting needs to be done for what elevation
Ok thanks that makes sense I bought it a little while away from my house so maybe the elevation is a bit different.I will look into the jetting and see if that helps it.
 

·
Registered
2019 YFZ450R SE
Joined
·
47 Posts
Ok thanks for the help that makes sense I will look in to the jetting

Ok thanks that makes sense I bought it a little while away from my house so maybe the elevation is a bit different.I will look into the jetting and see if that helps it.
Right on, if you make progress figuring it out please share. We will do the same as well. Frustrating how elevation plays such a significant role in overall performance😑
 

·
Super Moderator
Joined
·
3,132 Posts
Do you have the lid on or is it off? If it's still on try it with it off.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #9 ·
Update:so I have done a couple things over the past little bit. I tried taking off the lid of the air box but it didn’t really seem to make much difference also it has a brand new air filter from Yamaha that came pre oiled. I did the zip tie mod to it and that seemed to take away any hesitation in the low end. I have been messing with the jetting but It seems to be getting a bit worse if anything (stared as 155 main tried 158 and 160 so far but I will probably keep going).

It has a rpm gauge on it won’t go past around 4500-5000rpm does anyone know what the max rpm should be. I am starting to think it could have something to do with spark would a new spark plug possibly make a difference.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #10 ·
I just put on a new spark plug but it didn’t make any difference. I am starting to run out of things to try does anybody recognize this wire I can’t find where it plugs in not sure how important it is.
94662
7548C13E-54F2-4C37-84F2-921DD2E6A24B.jpeg
 

·
Super Moderator
Joined
·
3,132 Posts
What is your elevation?
 

·
Super Moderator
Joined
·
3,132 Posts
You will probably want to be at a 165 or 168 main.
 
1 - 14 of 14 Posts
Top