Honda Foreman Forums banner

running lean

11734 Views 10 Replies 6 Participants Last post by  roblarss
I have an 04 and I have been running on the stock jetting since new. Has been running rich but never got around to leaning it out. the other week I went out riding in an area I have been before but is at a slightly lower elevation (2000ft, home is 2700ft). I had to use the starting enrichment to make it run anywhere. Just backfired alot. Even then it barely ran. Seemded to run better (not perfect) for a little while then got bad again. I checked the plug and it was white. Took the carb apart all jets seemed clean, ended up raising the needle to the last notch and the quad seemed to run decent.
Any idea what happened? the engine has been making a knocking sound well before this but seems unreleated to this problem (another thread).
1 - 11 of 11 Posts
Is there any mods on the bike? when you say you raised the needle I assume you installed the e-clip in the bottom grove? if it was put in the top grove of the needle it would starve the engine of fuel making it run lean. you can also try to fine tune it with the air-fuel mixture. Just remember where you started. they usually come with the e-clip in the middle grove of the needle and the air/fuel mixture around 2.5 turns out.
the bike is completely stock. I took the e clip from the stock 3rd position to the bottom. I played a bit with the mixture screw but didnt solve much. Its just strange that it happened all of a sudden. Even with the clip at the bottom the plug still doesnt look great. Its just not bone white anymore.
its kind of odd but i can move my clip on the needle up 2 or 3 notches and it wont make any difference its startin to piss me off i cant get it to run anything like it needs to its got a real rough idle and i lost about 1mph off top speed but it seems tourqy that could just be me though
If it was running rich make sure the start enrichment cable has some slack in it and not stretched tight. Mine run rich and i loosened up the cable a little by pulling the cable housing down towards the carb. It was actually pulling the choke open just a little.
i pulled the vents off and thats not it i just took the carb apart and the choke has alot of play im still lost
How does it Idle? Could be a leak around the intake between the engine and the carb. Or a problem between the air filter and the carb. Mine wont run well with the air filter removed. (too lean) Be sure the air filter is clean and oiled like it should be. Be sure the rubber fittings are tight and in good condition.
another thought. Could the knocking sound be the valves or timing chain. Late timing or valves out of adjustment can cause backfireing or a Popping back through the carburator. Maybe check the engine compression. How many Miles do you have on the engine?
no i think the problem was the crankcase vent popped off i found out the hard way i went in a creek about rack deep and filled the motor up w/ water so yeah we'll see tomorrow
ill check all my vent lines. Ill blow some air through them to be sure. Ill try to do a compression test. Was fine before. Ill also do a leakdown test when my new tester shows up (old one was stolen). Im ready to take it to my dealer and give them a bunch of money to try to fix it.
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.