Man this video is just what I needed. I was pulling my dam hair out and ordered a JD jet kit to try to get it to richen up but nothing would work. My plate was upside down and when I swapped it now my idle is high as heck and I keep changing needle clip positions and main jet sizes that came in the JD jetting kit and it won't lower the idle enough. Now I am scratching my head on this one. Maybe float height is off since I tried adjusting it before to get it stop the lean crap it was doing.
Yes your float hight can affect the idle as well. What happens if the Float Hight is to low it will start to suck fuel through the main jet so no matter how low you set the idle it will idle to high... Now if the float is set to high and then it will idle to rich making it idle to low... It will make it run extremly rich and will idle like crap, bog when you stab the throttle (runs better when the "choke it pulled". Make sure that it's set to 8mm. When you make the adjustent make sure that the Carburetor is sitting at a 45 Degree Angle and the float is just barley compressing that small spring (the small spring that is in the end of the float needle) Basicully you wanna see the float "Bouncing" if you lightly shake the carburetor (when the carburetor is sittting at a 45 degree angle)
I hink I will. I was thinking soon I may just Redo my TRX450R motor for fun and go all out on it stroker and even bigger piston and maybe even go with Boost and a newer CRF450 EFI system.
I was have problems on my trx450 with a hanging idle. I pulled the slide out to find the vacuum plate seal was tore a little bit on the bottom I ordered a new one, I'm hoping this fixes my problem.
The vacuum plate in my carb isn't aligned with the throttle blade. When I open the throttle fully, the blade hits the top, but if I push a bit more, there's a click, and the plate moves all the way up, i am havibg issues like a lean condition, hanging idle, and bad popping on decel. Bike runs fine its just alot of popping an air fuel mixture is at 3-4 turns out and still popping. Could this be the issue ur deacribing in the video?
I took took off the carb and changed jets and cleaned the holes and checked the needle position which is when i noticed the plate issue. But because of my inexperience with 4 stroke carbs i didnt think anything of it untill i saw this video.
@@trxtech3010 vacumm plate was the right direction, i just cleaned the whole carb from top to bottom and swapped all jets + fuel screw and it works great now. My vaccum plate issue has to do with the throttle wheel being rusty and having some side to side play, along with the steam that the wheel connects to also had some play, but carb works so im just gonna leave it dor now.
Curious if you knew what the actual differences in the "M" and the "L" stamped vacuum plates. The OEM on Partszilla doesnt have a letter stamping, was curious if there was an actual dimensional difference between the two. The one from my carb isn't stamped either. My best guess was "M" for the MX bikes such as the YZ(f), and "L" for non-MX bikes such as the DRZ?
I'm not 100% Sure to be honest. Most FCR's I have seen with the M are just regular style FCR's in like the CRF's, TRX's, YZ, YFZ's, RMZ's, my best guess is that the L might be for the Down Draft style FCR's is my best guess. From my experience MOST of them are the same.
@@trxtech3010 Ended up picking up the M stamped plate and well... it was wrong ahaha. The "circle" where the seal sits is roughly 1mm too high, causing the plate to sit on a lip when installing it to the rolling throttle "cart". (forgive me, im a car mechanic, not a bike guy ahaha). So in my case with my 98 yz400f, the plates were different. Original one is unstamped, and the M stamped is the one thats about 1mm offset. I found this one on JDJetting and was hoping the M would fit, as they only offer M and L, not the non-stamped on. Everyone wanted 150+ for the OEM part number, and JDJetting offered it for 65. A main question I have, If I shave the top of the plate the one mill to fit on the rolling slide plate, would I be able to tune the difference out? I do believe it would offset the idle as its going to be a "millimeter out" persay. Its only a mill, but not sure if thats too much to be tuned out just to idle. Current plate is cracked and missing seal ahaha. Might try tig welding it back together at work or something if all else fails with the M stamped plate. Sorry for rambling.
@@trxtech3010 For anyone wondering. I originally had a no letter stamped vacuum plate, OEM from Yamaha for my 98 Yz400f. I bought the "M stamped" vacuum plate assuming "M" was for MX models like YZ, and assuming "L" Was for non mx such as DRZ etc. *remember these were assumptions as I couldn't find ANY information relating. On the plates, where you install the O-Ring to the vacuum plate, that "Circle" is about 1mm difference vertically than my OEM plate. I ended up shaving the top so it properly sat in the slide tray with a new seal. Installed. I'm hoping I can tune that 1mm difference out if needed at idle since I didn't have the time to get a new one etc. So I'm unsure if the "L" was the one I needed and I assumed wrong before. Ill also try to report back if I was able to get it to idle and tune the difference out with the "mod" I did to make it fit.
What way do i need to put the rubber o-ring around the vacuum plate? Does it need to be flush with the plate, or does it goes the other way around (kind of standing up - not flush)? I have a CRF250R 2007, runs lean all the time, checked almost everything - from valves to tps, leaks, jetting, etc etc.. Just cant get it right for some reason. Also, throttle is sticking when it runs, looks like some sort of vacuum problem. When i shut the bike of, pull 2-3 times on the throttle, it comes lose again. maybe someone can help me here, thanks :)
@@fintense So the Vacuum Plate Seal needs to be sticking up so it resembles an upside down cone is the best way to explain it. Is the throttle cable getting stuck or is the idle hanging?
@@trxtech3010 Alright, got it, thanks! The slide seems to get stuck when its running after 1 minute, not the idle (ofcourse it wil idle higher when it gets stuck). As soon as i shut the engine off, the slide/cable/carburator comes lose again bij twisting 2-3 times. I hear some air (vacuum) coming lose aswel when shut off and twisting the trotthle. the cable it self runs free.
wait there is a seal... i dont remember there beeing a seal on mine... it has a horrible bog i wont rev 0 to 100 u need to ease into it then it runs and you let if off it dies and we cant figure out the problem the spark plug is wet and black
Yes if they do not have the seal it will bot pull fuel from the Pilot Circuit and the only clway to make it run if by turning the idle up high enough till it can pull fuel from the Main and Pilot at the same time thencut becomes to rich. It's a common thing to miss on these carburetors.
@@trxtech3010 okay interesting to see will try and lookk into it... its anoying it ran fine we cleaned the carb ultra sound so removed all part and put new seals and jet and its all wierd now...
People with no experince I assume. I see it time and time again. They bring me a bike they "Cleaned" or "Rebiult" the Carburetor or had a freind of their do it and the bike won't run right, idles lean starts for 10 seconds and stalls. It's pretty easy to accidetally install it upside down but with experince you will remember which way to intall it.
Its happened to one of the bikes I bought before. Wr450f 05 had like a fucken 58 pilot lmao the slide piece was upside down and I guess they made it run good somehow
