nc riders,elevation changes

i was just curious,does anyone around 1190 ft' elevation have to change their jetting when they go ride at brown mtn(2725ft')? i was looking at my engine book and it says i should switch from a 172mj to a 170 mj and go out 1/4 on as.

just wondering if anyone had any problems or made any changes with this little of an increase in altd. thanks roy

Your problem is that within Brown Mt. itself you will find 800'-1000' of altitude change. You can go from the lower levels of trail 9 to the upper levels of trail 4 and see a difference. If you are off a little at 1190 then you will be off a lot at 2700' and it will really show up

In West Virginia we can climb from 800' to 3200' and back, all day long.

You have to experiment and find a good midpoint for your normal ride area. Seasonal changes will affect you also. What is good for me on Dec 1st is not what is good for me on July 1st.......

Clear as mud????

I never touch my settings, and I ride down near Columbia (at Enoree) and at Brown. Not sure what the elevation differences are, but it has to be quite a bit.

I wouldn't worry too much about the elev changes here. You may have to adjust the AS/FS a little, but you should be good if your jetting is close.

As said, seasonal changes will affect your jetting more so than altitude.

i had a small bogg sunday,but it wasn't to bad. i'm sure it is with the air screw

but i might try the 170mj to see witch does better for home and their also.

i had a small bogg sunday,but it wasn't to bad. i'm sure it is with the air screw

but i might try the 170mj to see witch does better for home and their also.

what bike? a bog probably does not have anything to do with the main jet, depending on where it is.

1999 300 exc,fmf garnley,

175 main

45 idle

n85c needle

2nd clip pos.

air screw tried between 1-2.75

when twisting throttle (while in neutral)comes off idle good,mid good,boggs out at wfo!

plug seems rich,fouled one yesterday. when under load dosen't seem like it wants to come off the bottom as clean as it should!????

1999 300 exc,fmf garnley,

175 main

45 idle

n85c needle

2nd clip pos.

air screw tried between 1-2.75

when twisting throttle (while in neutral)comes off idle good,mid good,boggs out at wfo!

plug seems rich,fouled one yesterday. when under load dosen't seem like it wants to come off the bottom as clean as it should!????

I don't know much about the older bikes and the carbs they run, so it's hard for me to recommend a needle/jet combo. You should ask the guys in the 2 stroke forum here, or go to KTMtalk, if you are a member.

I have been able to clean my jetting up on each of my bikes, however. I would start with a 3rd or 4th gear plug chop to see if you are rich on the main. new plug, straight away, close to WO throttle, shut it down and pull the plug. Then you can work from there.

There are some good needles for the 300, but I don't know if they will apply to your bike. Some needles just don't work as well, depending on your location. They are too rich in one area and lean in another.

1999 300 exc,fmf garnley,

175 main

45 idle

n85c needle

2nd clip pos.

air screw tried between 1-2.75

when twisting throttle (while in neutral)comes off idle good,mid good,boggs out at wfo!

plug seems rich,fouled one yesterday. when under load dosen't seem like it wants to come off the bottom as clean as it should!????

try a 170mj:thumbsup:

try a 170mj:thumbsup:

thanks,i thought i had a 170 but all i got is 172,175,178,180..

going to put in the 172 to see if that helps any. yamaha in hickory didnt have a 170 so i'll probably have to go to fun cycle to get one. bad thing is were going to drop back down in temp. this weekend. may end up chasing my tail with this crazy weather!:thumbsup::thumbsup:

thanks,i thought i had a 170 but all i got is 172,175,178,180..

going to put in the 172 to see if that helps any. yamaha in hickory didnt have a 170 so i'll probably have to go to fun cycle to get one. bad thing is were going to drop back down in temp. this weekend. may end up chasing my tail with this crazy weather!:thumbsup::confused:

You still should do a plug chop to see where you are on the main before just changing out the jet. easy test to keep from seizing the engine.

my bike runs good across the temp range.:thumbsup:

You still should do a plug chop to see where you are on the main before just changing out the jet. easy test to keep from seizing the engine.

my bike runs good across the temp range.:thumbsup:

will do,,,picked up two new plugs yesterday but cant run my bike that hard around my house (elderly neighbors through whole development) so i have to load-up and go to a friends.but i will check it. thanks

will do,,,picked up two new plugs yesterday but cant run my bike that hard around my house (elderly neighbors through whole development) so i have to load-up and go to a friends.but i will check it. thanks

no prob. take a pic of the plug afterward and post it up. I am curious to what is causing your issues.:thumbsup:

no prob. take a pic of the plug afterward and post it up. I am curious to what is causing your issues.:thumbsup:

i'll try to do the pics. but my computer skills are about equal to my jetting skills if not a little worse. if i had thought i could of brought my bike to work today and done it here.:thumbsup::confused:. that would be the only way i will ever get $$$ to work on a bike!

i'll try to do the pics. but my computer skills are about equal to my jetting skills if not a little worse. if i had thought i could of brought my bike to work today and done it here.:thumbsup::thumbsup:. that would be the only way i will ever get $$$ to work on a bike!

what part of NC do you live?

what part of NC do you live?

i live in sawmills but work in hickory

i live in sawmills but work in hickory

ah, you are not that far from me. I am off 321, south of Newton.

think i figured it out. i had been running regular instead of premium! i mixed 1 gal. of turbo blue with 4 gal premium and it cleared it up. runs great through all throttle range. feel kinda like an idiot for not thinking about the octane sooner.

think i figured it out. i had been running regular instead of premium! i mixed 1 gal. of turbo blue with 4 gal premium and it cleared it up. runs great through all throttle range. feel kinda like an idiot for not thinking about the octane sooner.

I noticed you went riding this weekend and wondered how it ran and what you did.

yep, it can change your jetting.

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