The YFZ Animal

[Henry]

Awk my debate is more along the line of ; do I attempt to broaden the power curve with the cam or just emphasize where the motor is already going to peak?. You are absolutely correct withthe stage 2 cams. That is exactly where the power curve will be the strongest. Im more just unsure if i should attemp to widen it a bit or just go for all out mid range power.dont get me wrong its gonna be nearly double the stock hp no matter what cam I chose.

@Quadman1 whats it need and location and how much.this prodject will be finished by the end of august and i really want a zilla. Id like to have a 90 but 87 can be builtup.

 

[Herpderplol]

go with a stage 2 cam.

a top end power add-on wont help a low-end power add on imo. like running a 35mm carb on a stock blaster

 

[harley1-5]

x2 on herps comment

 

[Larry's Shee]

Question might be best asked of your porter/builder.
Hard to get the best of both worlds.
S3 sounds like a drag only or drag/hill shooter style.
S1 might not be bad even.
No matter which way you go, be sure to check valve/piston clearance.

 

[Henry]

Clearances arent any big deal. The yfz's use shimmed valves. And im the builder lol. Sent the head to get ported but just had it opened up to breather better. I am torn between all 3 options. Stage one will bring the power on earlier but not peak as high. Stage 2 will peak super high in about a 2500 rpm range and stage 3 will stop it from falling on its face near max rpm but not as strong of a peak as 2. I was just currious if anyone had tried anything close to what im doing. Worst case scenario If I dont like it I can buy another set. But at 400$ a set I am hoping to get it right the first try. I am leaning toward 1 or 2. I hill climb and drag but 99% of my ride time wi spent with my lil 3 yr old buddy in front of me just putting around the trails and he points at everything he sees andsays " dabby wook at dat!" Lol

 

[Henry]

 

[Henry]

ok it's been a while, i got a promotion at work and it's taking all my life but i have gotten some work done. to quote Dr Frankenstein " ITS ALIVE!" but not quite finished. got some major jet issues to work out. it's running super lean but it runs and it's strong. i should pick up a few more horses once i get her tuned out.

 

[Awk08]

nice !
keep us posted as you get the bugs worked out

 

[harley1-5]

definitely let us know im watching for tips on mine

 

[dirtysquared]

Congrats on the promotion! The YFZ is looking good, just remember when your stressed out at work, you can always relax and play with your quad! That gets me through many a work day.

 

[Henry]

Ok update. I worked untill midnight last night and got the jetting close. Actual displacement is 563 cu in. My jetting is as follows. 52 piolt and 174 main. The exhaust was faintly glowing at idle after a few minutes so its pretty darn close on the pilot. After about 4 passes up and down the road it was cherry red again so need to step the main up a bit yet. Keep in mind 2-4 inches glowing red is normal on these, just not the 8" I had lol. Cool thing is that it stands straight up in every gear at half throttle Not dropping the clutch. Gonna have to change my exhaust though, the drag pipe is deafening to ride on. May richen up a bit once I change pipes. Gonna add a tooth to the front sprocket as well. I was topped out in 5th in a blink. She needs a little longer legs.

 

[Mert]

wow, this thing must be nasty. Good job on going all out. I just rebuilt my 450 supermoto and I chose to go stock because of the price. But next year I think I'm going to make a 510 out of it.

We need a video of this thing in action. Also are you going to stretch the swinger? Might help you get that ridiculous amount of power to the ground.

 

[Henry]

Still tuning it out and once I get the kinks worked out I will try to get a video. Im thinking hard about a +4 to +6 swing arm it comes up way to easily. But that may change too with a new pipe and new sprocket. Im probably going to get her all tuned out and ride it a few weekends to see what I like and what I dont on the trails. Once I get it tuned I am going to take it over to a buddy's garage and put her on the dyno. I will take a pic and post the dyno sheet when I get to that point.

 

[Henry]

ok changed to a 180 main and like it. took it up the road and strapped her down to the drums. had to ratchet it down and still was spinning rubber on the drums. had a few hiccups so i may need to move my needle one position to get it right. but here are the results



photo straight off the dyno screen. not bad for a little old four poker. now to the graphics and plastic and all the pretty stuff. if she runs good it's time to make her look good, right?

 

[rich1]

ok changed to a 180 main and like it. took it up the road and strapped her down to the drums. had to ratchet it down and still was spinning rubber on the drums. had a few hiccups so i may need to move my needle one position to get it right. but here are the results



photo straight off the dyno screen. not bad for a little old four poker. now to the graphics and plastic and all the pretty stuff. if she runs good it's time to make her look good, right?

Dyno looks pretty good but why is there not an A/F ratio measurement ? I know you said the header is supposed to glow but I would want a A/F since its a 4 stroke. A big bore motor can fry a valve before you can even get a plug reading. Just saying...

 

[Henry]

Jetting is right now. My glow stops around 3-4" off the head which is near perfect for these. This was just a freebee from a buddy that let me strap it to some drums for fun. Only insturment we hooked up was for the rpms. Titanium valves are pretty hard to burn up.

 

[Henry]

Got a current pic. Started masking and taping and lite sand blasting to give it a gloss black and flat black look on the plastic.

 

[Blaaster]

Titanium is rather heat resistant, unfortunately the same cannot be said about the piston.

 

[Henry]

The exhaust glows because its paper thin titanium alloy. Most yfz builders dont bother with a full exhaust because the most power increase ive seen is about 4% over stock. However the muffler gives 16% as a slip on only. They glow straight off the showroom floor with a stock setup. Its just how they run. I know it seems strange to think of it like that but you can view it on YouTube or google it. All of them do it. Even with my headder glowing I can lay my hand straight on the head and cylinder jug and its just warm to the touch

 

[Mert]

Titanium pipe on my 450 supermoto, can confirm that they glow.