2007 Raptor 350 build

[YamahaNutz]

I'm bored with the bad weather, and thought I'd share on this forum. I've gotten a ton of info searching here.

2007 Raptor 350. Original engine condition unknown. I immediatly swapped a rebuilt 87/93 warrior assembly. Destroyed the cam and head, swapped a rebuilt '87 head on with diy port work and a Ninche cam(cheap). Now I'm looking to upgrade the cam and put down reliable numbers.

Engine:
'87 base with '93 internals
Wiseco 11.1 piston
Niche 1557-3 camshaft
FCR MX 37mm carb from '07 YZ250F
Custom machined Wolverine intake adapter
HMF for '04 YZF450 lengthened to fit
Heat wrapped exhaust
K&N filter
Drilled air box lid
 Big Bear 350 oil cooler mod w/ cooling fan
Big Bear 350 vented camshaft cover
Extra steel in clutch with stiffer springs
Moose case saver

Frame:
Aftermarket replacement harness assembly
YFZ450 throttle and clutch(on stock handle bar)
 Air scoops cut from YFZ450 scoops
Unknown brand +6 swingarm
Unknown modified 1/4" aluminum swing skid
YFZ450 Tusk nerf bars
Early YFZ450 front shocks
YFZ dual piston front calipers
American Star LTZ400 +2-+1 front arms
Diy chromoly +2.5 steering stem

Had a '87 Warrior before buying this quad. I felt the Raptor 350 improvements immediatly even though it's mostly the same.

I actually have just completed the front arm swap and steering stem. Have not ran it since.

Plan is to run it, dyno it with the niche cam, then do another head build with a better cam. My research has told me I over did the porting on this head. So I'm going to do a more simple port focusing on flow turbulence instead of going for bigger.

Also doing some diy cut wide foot pegs that will bolt on to the factory ones with the nerf bars. I keep loosing foot hold and bouncing off the stock ones. And looking to replace the slightly bent rear axle shaft.

Only have pics of it dirty currently. FCR carb has been tweaked with a different needle and a R&D bowl kit. Just swapped on some 23x7 front tires over the 22x7 standards.

It runs great. Last October it went to the Silver Lake dunes. No complaints except carb was not dialed in. And it falls off in power in high rpm.

 

[beastlywarrior228]

Looks like you're off to the great start. I think we can easily get you in the 40's hp wise with more head and carb work.

For the head you really want to pay attention to the flow around the valve guide and valves. That's where you can gain or lose a lot.

Cam depends on what you're looking for. Good woods setup the new xc web cam. Mid to top, web .430. Top end megacycle 252x1. If you end up doing more compression and larger piston it will be 100% 252x1.

For the carb I would really recommend going to the 39mm. The 37 is great for stock head motors but you're leaving a lot on the table on the top end after porting.

 

[YamahaNutz]

To be honest, I'm a cheap-a$$. For longevity, wear wise, I was looking to do a hot cams stage 2, which I have found is close to a web .390, with a more stock ramp angle. I want to swap a stock cam sprocket pin when I install it to avoid the broken pin issue they have. Only reason my cheap niche cam failed is the roller pin rear bearing smoked out(chesp bearing), and it over-revved alot. I'm building the newer head with a rear ball bearing. I'm not seeking max power. Just want reliable, consistent, power. This would also allow me to keep the 37mm fcr and tune within its limits. I sunk alot of effort and money into this carb already.

I did the new D.I.D. chain, factory chain guides, and kibble white valves/springs already. The current head was done at a reputable race engine machine shop. But, was way out of range for valve seat surface(head was warped). I also did the newbie mistake of taking too much material out of the ports, including some from the floor. I have silicone molds of factory ports to measure from now. So yes, I'm going to focus on the shroud, and only blend the ports. My research has led me to believe the ports are almost too big from the factory unless you have a big bore/stroker. I can get a high quality valve seat job done on the newer head.

I just want this quad to run, have fun, and last. Seen too many "expensive" builds chasing max numbers. I'm already deep into this quad, with mostly used parts. Ill hit a track a few times a year, maybe 1 trail ride, and sand dunes a few times. I'd get a 2-stroke if I wanted to go the fastest(money-pit).

 

[YamahaNutz]

What is everyone's opinion on the Streamline 7-way rebuildable "stick" steering stabilizer? Found one new for just over $100.

Foot pegs came out great! Hopefully my yard is dry enough to take it out this weekend.



I can already assume the huge widening arms will make it feel like a completely different quad. I want to take it to a private owned track soon.