brentn

Pull the cold start knob out and try, yes it works very well when the engine is hot.

Thing is, there is never any real hard proof that a particular oil killed an engine. I love how people will post about how they changed to brand x and then 4th gear blew up, then they say that it must have been the oil and they condemn it and slander it all over the net. These said people are the ones who have no idea how many other factors are involved, such as -Riding technique, are you rough on the engine, grinding gears etc? -Not changing their oil often enough over the period of years leading up to the said event? -Metalurgy of the gear, was it bad from the factory? too brittle, not forged properly? Maybe small fissures that went past QC? -Crank case breather had a hole in it near the top, or was designed poorly in which dirty air enters the crankcase/gear oil? -Other possible issues that only real engineers can even think of and not myself. All of which would probably have nothing to do with said oil.... lol.

Keep us updated on this, I love reading sweet justice threads when they rarely happen on these boards.

A really good technique for saving head bolts is to re-die them with a tap and die set. Using the same thread pitch and size of course, work the die up and down the threads once, this will remove all corrosion or deposits that cause a bolt to not torque properly. Weather you get new bolts or not, you should re-tap the head in a similar matter, make sure you use oil. This way your gauranteed to have an accurate torquing of the bolts.

They should be able to take the abuse of a kick, looks like a metallurgy problem with the gear and nothing with your technique. Either way, I find it much much easier to start a bike in nuetral, with the clutch held in there is still a little drag and it makes it just that much more difficult.

In the link a user has posted the stock stack along with his own, but I think this should help /topic/857679-help-diy-pro-style-fork-revalve-yz450f-10/

I do now 👍, thx for the info, but yes it's about .6 gallons smaller than the 250....

Yes use both, take your finger and put a thin film of the RTC on the gasket and then then flange on the engine itself. Place the cover on, screw in your bolts finger tight, and tighten them in a criss cross pattern all the way around. Remember do not use too much leverage on your ratchet driver, you'll strip the bolt for sure, just snug them up and then like 1/8th turn tighten. Make sure that the flanges are perfectly clean, and that no oil will run down while you are doing this, if this means you should lay your bike on it's side so that residule oil doens't leak out, then do it. Let it dry over night before you fill and ride. I use the red/goldish high temp RTV from permatex for these kinds of things, works every time.

gonna try that out, thanks!!!

How are you guys doing it? My bike just doesn't have enough torque in 4th to lift the front wheel up much at all. I will try and wheelie by riding in 3rd at high rpm and then gear up to 4th and try and snap the throttle while adjusting my weight to the rear and pulling up. If i'm coming up to a small hill in the dirt road I can lift the front off just a bit when I cross the highest point, but that's it. I can only conclude that you guys are gearing up but holding in the clutch, getting a high RPM and then letting it out quickly while adjusting your position on the bike to lift up at high speeds? I'm slightly afraid to try this cause I'm worried about wheel spin in the rear or too much traction depending how I lean and then I crash hard. I can do wheelies no problem from stop to start, or say at a slow speed and in 2nd and pull a small cat walk... thx for any advice!

I owned a yz250 2 stroke 2005 for about 2 years and have now owned my 2010 yz450f for 2 years and I can say that they were both consuming the same amount of gas... I judged it by tanks, and for a similar trip on both bikes the tanks would be at similar levels...

There are jets in the carbuerator that regulate the amount of fuel that enter the engines at different running speeds. The choke is designed to "choke" off air to the carb to allow more fuel to enter the engine when it is cold. WHen an engine is cold it cannot use the regular amount of fuel the jets supply and needs more just until the engine warms up. Once the engine is warmed up it will run very poorly with the choke engaged, and flicking it off will allow the bike to run properly if your jets are tuned properly. If you cannot run the bike without the choke even after it is really warmed up, then your pilot jet which is used to regulate fuel at idle, is either too small or clogged. You should do some google searches on how to replace a jet for a dirt bike, there will be pictures and all kinds of other info that you'll need in order to do it yourself. If your not comfortable, bring it in to a mechanic and let him do it for 80$ an hour.

lmao 👍 too funny,

I also bought a 10 and still have it. I went from 0 hours on it to 55 and it's holding up very well. I will agree with the crankcase breather hose location for large puddles/rivers, I was also sucking up quite a bit of water, so I re-routed it. Issues that I have had with the bike; -Starting cold is never a problem, hot starting can be tricky. The valves have never moved on this bike, and are in spec but the starting circuit is 'weird' to say the least. If you stall and try to re-start it will fire up with a couple kicks 5% of the time, otherwise you'll be kicking forever. I used to give the throttle a slight twist while kicking and it would start up 95% of the time doing this. Later on I started to pull the cold start knob out for a hot start, and without any throttle movement the bike will start 95% of the time first kick hot. I bought a power commander 5 for the bike and changed the starting circuit to supply a bit more fuel to the circuit for the first 30 seconds, this helped quite a bit but did not eliminate the starting issues. -On second thought I cannot think of any other major issues lol... I absolutely love this bike however, and it has served me very well on the trails I too also added a slip on and the top end power increased very noticeably!

Glad that you are replacing jets instead of trying to clean them, costs 12$ for both and your guaranteed to know that they are going to work 100%. I pulled my sisters china 250cc out of the garage last saturday, very similar to your 230f, replaced the battery and fired it up and blue smoke everywhere! It fouled the plug so I pulled it out and shot sea foam into the cylinder and cranked it over. Cleaned the plug and put it back in, but still blue smoke, let it fully warm up until I just remembered that I shot quite a bit of oil in the cylinder before winter for storage 👍 Runs fine now.