Honda ATV Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Hello all
So I have a stock honda trx 400 ex 2005
my spark plug looks like this... super powdery black

my 4wheeler starts perfect , runs good and has had nothing ever done to it , all original parts & jets
Only the exhaust baffle is out

I did notice my garage stinks of gas upon start up and twice upon high revs trying to keep a wheelie up my brother saw some black smoke come out the exhaust

Why would my spark plug look like this?
Would adjusting the air/fuel screw make a difference(I just don’t have that special d took)
Could it be time to change piston rings ?
Should I try running the bike without the air lid with a new plug and see if it comes out tanned or not so black lol
150884
 

·
Premium Member
Joined
·
4,200 Posts
Compression check could rule out ring or valve wear.
Dirty air cleaner?
I would inspect the enrichment valve if it has one and replace if the seal is worn. Rebuild the carb.
If the choke and carb is already tip top then Yes try turning the pilot screw in a quarter turn but if it starts stumbling then reset
 

·
Registered
Joined
·
12 Posts
Discussion Starter #3
Compression check could rule out ring or valve wear.
Dirty air cleaner?
I would inspect the enrichment valve if it has one and replace if the seal is worn. Rebuild the carb.
If the choke and carb is already tip top then Yes try turning the pilot screw in a quarter turn but if it starts stumbling then reset
Thanks for the reply ! Do you think this could be the problem, that I mostly ride on slightly closed throttle to mid throttle ( I use my quad around the village I live they are legal here) do you think a smaller pilot jet will do? It has a stock #38 in it now
oh and my air filter is super clean
 
1 - 3 of 3 Posts
Top