4,514 posts in this topic
I have a 2004 Yamaha WR250F that the previous owner modified and the bike doesn’t run the way it should. It has an FMF muffler with an aftermarket pipe coming from the engine. There’s no other silencers or restrictions in the exhaust.
When I got the bike, it was backfiring every time I let off the throttle no matter what speed I was doing. When the previous owner first started the bike, part of the exhaust pipe was cherry red while he was warming it up by giving it more throttle.
I took the carburetor apart and found out that I have a 178 main jet, 40 pilot jet, and 72 leak jet. The needle clip was in the middle in the 4th position. I adjusted the fuel screw back to the 1.5 turns out position from the 3.5 turns out position the previous owner had it set at. I changed out the pilot jet to a 45 and the bike no longer backfires while I ride it but it does die when I leave it to idle. Sometimes it dies immediately after letting off the throttle and other times it will idle for a minute or two before dying.
Now before this gets too confusing, I ran the bike with the fuel screw at 1.5 turns out and 3.5 turns out after changing the pilot jet. At 1.5 turns out, the bike would only run when choked and would die when idling. At 3.5 turns out, the bike will run with the choke off but will still die when idling.
If anyone has any suggestions to try, please let me know.
CANT FIND A STRAIGHT ANSWER ON FORUMS , NEED HELP NOT SMART ASS COMMENTS
Background - cool weather has me motivated on doing a ground up restoration on my 97 yz250 , last year I fully restored my first bike that got me into the sport a "1993 yz125 " . Just like my my build last year It seams Im stuck with the bastard children of Yamaha , parts are hard to find and seems to be little or no aftermarket parts. I have already spent well over $1,000 on this yz250 in plastics , custom graphics , asv levers , custom gas tank , exhaust and other crap so the most cost effective way would be best lol. I'm wanting to change the look of the bike with black wheels , rims are 160-220 each depending on brand . spokes are 60+ each set and labor is about $200 locally to lace and true . I have searched high and low on forums and google haven't found a single aftermarket set that fits a 1997 everything is 99+
Question - I have found a newer set of wheels https://www.rockymountainatvmc.com/p/1071/42645/Tusk-Impact-Complete-Front-Rear-Wheel-Kit what do I need to make these work on a 1997 ? I know my hubs are 20mm and 99+ have 22mm. if you could help with part numbers or links on what I need.
Here is what I'm going for ( top pic ) the one below are my progress , frame goes to power coating tomorrow
So i just rebuild my top end of my 2005 250F, i had 35 houres on my piston and cylinder so i decided to rebuild it.
it ran perfectly before the rebuild, my timing is right, i have spark, en my sparkplug is a little wet so i have fuel... If i try to kick it it starts to run but after 2seconds it stops running. does anyone know what i have to do?
thx Medard from belgium
By Henry Gooner
So I am 270# and 6'. I used to ride and want to get back into it. I definitely have a good amount of experience to handle both a 250 and 450 but not sure if a 250 will be able to handle me.
Right now the bikes I am between are:
2012 YZ450F @ 50 hours for $4000 CAD and trail ridden https://www.kijiji.ca/v-view-details.html?adId=1302150376&requestSource=b 2012 KX450F @ 35 hours for $3800 CAD and trail ridden https://www.kijiji.ca/v-view-details.html?adId=1300722287&requestSource=b 2010 CRF450R @ 45 hours for $3200 CAD and trail ridden https://www.kijiji.ca/v-view-details.html?adId=1296942462&requestSource=b All these bikes are in really good condition from what I can see from the pictures and none of them raced or track ridden. My plan is to build a 5 acre track in my backyard and build some sort of track along with mainly using it for trail riding.
I guess what I am asking is for some suggestions and opinions that could help me decide.