Honda ATV Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 · (Edited)
Hello everyone. I have an 05 honda trx450r that was running rich and had carbon build up on the plug and inside the carb when I bought it. I cleaned every aspect of the carb, ordered an fmf power up jet kit and a flex tech fuel screw. it had a 175 in the main jet from the previous owner and I put a 180 in and it still has the stock pilot which is 48. The needle is on the 3rd notch. It Use to have a hanging idle and didn't really wanna stay idling at all. Now with the new parts and the cleaning it runs a lot better but still has a hanging idle but not as bad, I pulled my new plug I had put in there and around mouth was kinda dark still yet but it was a dark brown on the plug itself so I feel like I'm getting closer to getting it to run right. I'm curious as to if i need to go up in jet size even more yet? It has no air box lid, a mild cam and a full hmf exhaust. It's winter here right now so it's cold and I'm about 1000 ft sea level.
 

Attachments

·
Super Moderator
Joined
·
18,227 Posts
Hello everyone. I have an 05 honda trx450r that was running rich and had carbon build up on the plug and inside the carb when I bought it. I cleaned every aspect of the carb, ordered an fmf power up jet kit and a flex tech fuel screw. it had a 175 in the main jet from the previous owner and I put a 180 in and it still has the stock pilot which is 48. The needle is on the 3rd notch. It Use to have a hanging idle and didn't really wanna stay idling at all. Now with the new parts and the cleaning it runs a lot better but still has a hanging idle but not as bad, I pulled my new plug I had put in there and around mouth was kinda dark still yet but it was a dark brown on the plug itself so I feel like I'm getting closer to getting it to run right. I'm curious as to if i need to go up in jet size even more yet? It has no air box lid, a mild cam and a full hmf exhaust. It's winter here right now so it's cold and I'm about 1000 ft sea level.
First of all the R&D flex jet is not for 04-05 carb they are for FCR carbs only. The taper on the tip is entirely different. I would put the stock fuel screw in and set it to 2 1/2 turns from lightly seated. If your plug is dark brown it's a little rich dropping back to a 170 may lean it out enough? I have a jetting how to in my signature that should help explain how to jet your carb accordingly?
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 · (Edited)
I was told by our local power sports shop called zaps that this would fix some of my problems, and I contacted R&D about this product which I then ordered one that fits a stock 04-05 honda trx450r butterfly keihin carb. With the stock screw it doesn't really even make a difference with how it has been running, just makes it easier to get to and adjust. Stock screw I played with from 1 turn out all the way to three and a half so it's not that. After installing the parts it's running a lot better which I've mentioned in my previous post. As far as jetting I've played around with 175-170-165-160 and the lower I go the more rough idle it has and almost chokes it out. The plug I removed from the previous owner this the 175 main jet had a lot of carbon build, now with the 180 and the fuel screw set to 2 turns out it's dark brown, I know it's gotta be just a tad lighter brown so I think I'm going to order a bigger jet seeing how most of the forums I'm reading, people are using a 190 to 200 with the same mods as I and getting good results. 450s come off the assembley line running lean to start with.
 
1 - 3 of 3 Posts
Top