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JB500 Liked a forum topic Fast Freddie Makes a Kids Day
3/10/2025 12:02pm
My son is a big Freddie fan. He waited for quite a while to see him yesterday, and when he came out to head into the stadium, stopped and talked with my boy for a minute. Just calling out the 33 and his mechanic for being nice guys and making a kids day.
This forum topic has 11 replies.
modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
12/15/2024 10:20am Sounds very similar to our setup then :-). We are running the stock cams. Just moved the sprockets. As long as you don't move the rev limiter to far this setup should be as durable as stock ( I think/ hope...). We haven't had to change anything but clutches this year.
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modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
12/15/2024 10:02am More overlap, so also got even less engine braking as a "side effect". The exact cam timing needed will depend not only of the inlet lenght, but also exhaust used (we ran Acrapovic). I'm pretty sure all good engine buliders go approx the same route...
modin Added a reply to How much does the factory 250F rev today?
6/12/2024 12:52am Would be interesting to make a list with rpm of the different factory brand/bikes. I'm most curious of the Yamaha star 250s. Has anyone used the Engine RPM app to measure this trackside? I'm pretty sure the factory engine guys knows this very well in detail. 250 race bikes Star Yamaha ? Triumph? Club MX Yamaha? Factory Honda? PC Kawasaki...
modin Added a reply to YZ250F 2024 springs
6/10/2024 5:44am I think you would benefit from softer suspension. As long as the sag is ok I think you can get away with softer springs and run the stock shimming. I you are not super fast I think you will prefer the comfort of a softer suspension.
modin Started a new thread How much does the factory 250F rev today?
6/10/2024 5:12am We have all heard the sound of a Star Racing 250F, but what engine speeds are they at today? I've heard that when Cosworth built the Yamaha GP 250Fs (that always broke...) they aimed for 17500 rpm. I would guess that all the "factory" bikes are above 15000rpm today, but don't know. Shouldn't be that hard to do a frequency...
This forum thread has 2 replies.
modin Added a reply to Will a kickstand from a YZ125X fit on the MX version?
6/7/2024 5:13am It sure fits, but you must buy the bracket as stated above. Only bad thing with them is Yamahas pricing....
modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
5/6/2024 6:29am The bike seem to rev out like before (or better...). Not sure exactly how long the complete inlet tract is with the funnel, but it protrudes (if that is correct english...) approx 2 cm into the airbox. Looks like this.
modin Added a reply to If you could go back in time and put a GoPro on any rider for any race, which would you pick?
5/4/2024 7:10am Barcia when he took out Ferrandis outdoors (don't remember which track).
modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
5/4/2024 7:07am Forgot to update this one... Since last I got the carbon fibre funnel and had it on the dyno. First we actually tried the "old" funnel from VHM and just glued it in (similar gains but 8mm longer than the new one and fits "so so", but god enough ). Recently we got new funnels made for the 2024. The...
modin Added a reply to YZ125 leaking oil from powervalve cover
3/26/2024 6:25am Have you had anything done to the cylinder lately? If the seal in the cyl around the shaft to the actuator arm is missing I guess it could leak there. That oil is dripping out of the vent hose on the other side is std.
aburke Liked a reply to forum topic 2024 yz250f "airbox funnel mod". What parts?
2/13/2024 9:41am
The 450 boot will not fit the 250 without an adapter, the 250 engine is smaller and the boot doesn’t quite meet the throttle body. As for the ‘23 v ‘24 air boot they differ up top and angles but the clamping diameter are the same. I’ve never had the VHM insert but I’d assume it’ll jam in the new boot.
This forum topic has 17 replies.
modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
2/11/2024 1:26am If this fits the -24 and the previous, it can't be shorter / bigger than the earlier and should solve the problem. Anything loinger/smaller will improve low rpm torque (so no need to be sorry on your end :-) ) I can rephrase my question to VHM and see if it fits. If it does it should be worth testing...
modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
2/10/2024 8:39am Could be. Strange that they say it fits 2021-2024. Think the -24 airbox differs from the earlier (that's what all this is about :-) ). I mailed VHM and asked and they said they would have a -24 on their dyno in a few weeks and would have a look at it.
modin Added a reply to 2024 yz250f "airbox funnel mod". What parts?
2/8/2024 9:44am Guess it is only a matter of time before someone makes something like this for the -24. I will mail vhm and ask. https://www.vhm.nl/en/catalog/engine-parts/filter-parts/air-intakes-air… If the 450 air box isn't plug and play I think I will try to get a funnel made to try in the original 250F airbox. Then you could make several different lenghts to try what...
modin Started a new thread 2024 yz250f "airbox funnel mod". What parts?
2/4/2024 10:52am Has anyone tried fitting the 450 air box case to the 2024 250F? I think this it what Twisted uses with their kit to get back the low end torque the new airboot seem to sacrifice. I had a look at the Yamaha parts on the web and it looks like the 450 airboot can fit. The throttlebodies has the...
This forum thread has 17 replies.
modin Started a new thread YZF what tool to mount piston in fork cartridge?
12/6/2023 10:36am Just changed from YZ125/250 (current gen) to 250F. I find it way harder to remount the pistonband without damaging it in the inner cartridge after service/revalve on the 4 stroke than on the 2 stroke KYBs. On the 2 stroke it more or less "fell" in but on the F KYBs there seems to be no chamfer that guides the...
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modin Added a reply to Triumph TF 250-X
11/28/2023 9:28am If it is 229lbs the engine need to be quite strong to have best power to weight in class. Don't think they would dare claim that if they weren't. I know they have been benchmarking the other bikes since long.
modin Added a reply to Exhaust Baffles
11/15/2023 5:04am What bike is it? Sounds like you have a catalyst in it? In that case I would say it can be normal.
modin Added a reply to Now Available! YZ-EMX Full Electric Conversion Kit from Electro & Co.
11/9/2023 9:50am What kind of inverters are you running? Can it charge so you have enginebrake, or is it only positive drive? If regen, can you tune it? No engine or battery cooling from what I can see?