Posts
9376
Joined
4/1/2008
Location
SD, CA
US
Fantasy
1271st
Edited Date/Time
10/16/2022 7:55pm
2020 was a weird year for all of us. As a 2-stroke diehard even I needed a change and decided to finally pick up a farting 4-stroke. I love 250 2-smokes but also love underpowered 125s and how they really reward you when you ride them well. I'm treating this similar and starting out with an 'underwhelming' platform and see what minor stuff I can do so I enjoy riding it more and more.
This is intended to be more informative for those interested, not a balls-out build. Wasn’t sure if this should go here or tech forum honestly.
Thought this would be nice to do for a few reasons:
1) People HATE on the bike and act like it has half the horsepower of every other 250
2) Since the RM-Z suspension comes so far off for most people in stock condition.
Day 1: Picked her up in the pale moon light.
This is intended to be more informative for those interested, not a balls-out build. Wasn’t sure if this should go here or tech forum honestly.
Thought this would be nice to do for a few reasons:
1) People HATE on the bike and act like it has half the horsepower of every other 250
2) Since the RM-Z suspension comes so far off for most people in stock condition.
Day 1: Picked her up in the pale moon light.
I could hardly move the forks in the garage, they are so stiff. I spoke with ENZO Racing and ended up picking up .46 kg/mm fork springs and 4.8 kg/mm shock spring (I weigh 148 lbs). I'm also starting off with less oil in the fork legs, 340ml.
The Shop
One thing to keep an eye on is your wheels. I have about 20 hours on my 2020 450 and both rims are a weebln and a wobblin real bad. Flat spots and taco shells front and rear.
I usually go through a set of rims per year but these didn’t even make it 4 months.
They must be made of recycled Pepsi cans.
Suzuki's dirt stars are probably the same thing. They are actually made by d.i.d just a lower spec because it's cheaper. Unlike ktm/husky that spec's the higher grade real versions on their bikes.
Although ktm tried to go to the cheaper excel rim back in '12 '13 and got a lot of complaints from people bending them. So they went back to using the higher grade excel. Excel must be making a lot of these lower spec rims. Because they just came out with selling an economy line called the excel ONE line of rims. And they recommend them more for the casual rider not mx'er.
im a suzuki die hard and have mad multiple rmz250s and rm125's
So I spoke with Yoshimura techs the other day and they told me the rs-4 and rs-12 will see the same gains. As always, there are positives and negatives to most decisions. Staying true to the frugal form, I opted for the stainless steel rs-4 full system. I almost chose the titanium system but I opted to spend less money.
Positives:
-Same gains as more expensive rs-12 system
-scored full system for $400!
-I actually think the muffler looks better as it slims down in the rear compared to the rs-12 (just my opinion)
Negatives
-No real weight savings, was 1 ounce lighter than stock
The system install was a breeze! This thing fit like it was OEM and I appreciate that after having many issues with systems over the years. Riding tomorrow so I'll finally get to the performance of the stuff.
Thanks
Pit Row
Got to ride Cahuilla Creek on Friday (special opening because of crazy weather lately). The dirt was mint and the track was not very rough, yet a few jump faces got really rutted so they were tricky and causing people some grief.
Ergonomics: I'm 5'8" and this thing feels comfy right away, similar to when I jumped on a Honda 250f. Nothing feels weird, with the bars rolled back a little and levers where I want them, it is super comfortable.
Handling: Like a broken record at this point but these things have to be the most nimble bikes around, excluding 2-strokes. This thing turned like carving a knife through warm butter. On the faster straights I didn't get any unexpected twitches though the track was a little on the smooth side compared to days with a bigger crowd.
Motor: Pretty much what I expected out of it with some nice surprises. There were some rather tight corners on this track that I'd ride in 2nd on my 250sx and this thing pulled 3rd gear and barked out of them. This grunt out of turns really impressed me. The spot it felt most lacking (especially compared to my old 250sx) is a long left hander into an uphill to a finish line jump at the peak. I'd ride the corner in 3rd and then grab 4th and it would struggle a little bit up the hill to gain momentum. I'd imagine this is where some head mods or something like the package JGR was selling would really wake up that top end.
Suspension: Starting out with springs for my weight/level and 340ml oil in the forks, the suspension was still stiff prior to breaking it in. I couldn't even get to the stock starting point of 110mm rear sag on the shock because the shock spring was getting too loose. I started out with 104mm and just went and rode with all the clickers at stock positions. Bike handled very good overall. With some weird rutted jump faces I cased landings a few times and the bike packed up and still didn't use all the travel. I ended up going out 2 clicks on the compression and 1 out on the rebound and it felt more compliant. I'll have to see how that progresses as the suspenders break in.
I intended to check/set the sag again at the end of the day with my gear still on but my buddy cross rutted and got a concussion so that didn't happen. Really pumped to try the bike on another track, like the tighter/jumpier Statefair mx and see how nimble it feels in those tighter sections.
Biondo, don’t let JWACK fool you. He’s a damn good/fast rider.
I noticed my travel is almost to bottom with 4.2 springs and 325 ml oil ..did a few laps on the main track couple weeks ago trying to get over fear of jumping...having fun learning! Hope you’re friend is doing good...
I noticed they changed tracks adding some length and corners were a bit rutted out! Still trying to figure those out🤓
Anyways Great update !
Change your oil & filters
Had a few shavings after break in but the surprising part was how much paint was caught in oil screens. Yellow paint, from marking internal fasteners, was clogging the screens pretty gnarly. You can also see a little metal shard in the upper right.
Rode a track that is completely different than Cahuilla (Barona mx) and noticed a few new things.
1) Suspension update: I think Enzo nailed it on spring rates for me and the bike felt really great and balanced at this track as well, no complaints.
2) Engine characteristics: Rode with the aggressive map from the wifi tuner app loaded and bike felt great overall (Side note, people commented that the bike sounded sick, so that's always a plus!
One thing that this track brought out was the short comings of the top end ability to rev out. There is a long downhill at this track with a few jumps and chop. On my 250sx I would just hold 3rd gear and all was well. On the RMZ, I'd be in 4th gear and when it rev'd out, it would almost feel like I accidentally clicked into 3rd because it would drop off rather abruptly. I think I am just used to holding a gear and reving bikes out in general (I'm a 2-stroke guy inside). In hindsight, I should have experimented with grabbing 5th gear but I never did that. The bottom end/mid range is impressive on the bike but now I'd love to try and improve the top end characteristics.
Thanks Warren
Fox Sunday a bit crowded! Thought everyone would stay home since it was super bowl...just wanted to compare YZ250 F and the YZ 2strokes....To my RM250 and RMZ 250
The YZ250 F was quite impressive! Definitely a bit more power ! And electric start is nice ! The handling was plush! Didn’t turn like the Suzuki...really stable at speed And instilled confidence!
But New bike will have to wait...
Anyways looking forward to seeing your
Build in action 🤠
Ciao Warren
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