Here is a 2-stroke modification to increase the blow-down time and increase the exhaust pulse signal strength to the pipe. This modification is not for beginners and can be done by hand, machine, or CNC. The summary of the mod is to modify your piston dome to match the shape of the upper portion of the exhaust port (the curve of the oval). This allows more area to open for the exhaust to exit in a shorter time (degrees). One method would be to blue the exhaust side of the piston, insert it into the cylinder up to the point of the exhaust closing, and mark the piston with a dental tool (sharp narrow tool). Next mark on the piston the outer edges of the exhaust port (some thought when modifying triple exhaust ports). Finally decide on the limits of upper land on the piston, the angle of the cuts, and edge cut radiuses. Carefully cut the piston(s) with appropriate tooling. Here are some example pics of how to modify a Blaster engine. Many other layout and/or machining approaches are, of course, possible for this modification, and exhaust port timing as well as time/area need to be considered.
Wheeler Piston Scallop Mod (WS Mod)
By Bobby Iverson
Was riding my 450, testing out a new speedometer, shifted into 2nd, moved a couple feet and heard a loud crack noise from engine area. Will not turn over, sounds like its jammed or seized from moving. My guess is tat the timing chain just exploded and fouled everything up. Haven't found time to open it up. Thought I'd go to forums to get some opinions on what to look at first. As far as back round info: Engine was opened up to replace some gaskets. replaced my valves and adjusted rockers to .05mm. Timing chain taken apart a couple times. Shifts through gears fine even though it doesn't run. I am not very fond of ktms or dirt bikes in general but fairly mechanically inclined. I don't know what to do so here I am on the forums. Any help or advice is much appreciated. Thank you.
hey guys ive had my drz for about a year and recently the little hole on the left side of the engine has started leaking what looks like oil, ive read it could be a head gasket or something failing but I have no other leaks and the bike still runs fine.
can someone please tell me what this hole is for and why its started leaking recently. thank you
By Kevin from Wiseco
Attention two-stroke riders! For a limited time, Wiseco is offering to let you choose up to two FREE items with proof of two-stroke piston(s) purchase! Read on for all the details on this offer.
Who doesn't love the sound, smell, and fun of a two-stroke? Wiseco has a new rebate offer just for the two-stroke lovers! For a limited time, Wiseco will be offering your choice of up to TWO (2) different free items with a minimum purchase of any off-road bike or ATV Wiseco two-stroke shelf piston(s)! Choose from our new high-quality, modern-fit Wiseco T-shirts, the new Wiseco Patch hat, or a top end gasket kit! Simply pay a flat $10 shipping fee.
Click here to go to the Two-For-Two-Stroke rebate form!
How does the rebate work?
To participate, follow the instructions below. Purchases must be made between TWOsday August 28th and TWOsday October 30th, and redeemed by November 30th.
Purchase a minimum of $118 of any new off-road bike or ATV Wiseco two-stroke shelf piston(s) for ONE (1) FREE item, or a minimum of $165 for TWO (2) FREE items.
Save your receipt/proof of purchase and piston box.
Scan or take a photo of the proof of purchase and the piston box label showing the part number, and upload to the online rebate form.
Click here to go to the online rebate form, fill it out completely with all required information, be sure photos from step 3 are uploaded, and submit.
Allow 1-2 business days to be contacted by a Wiseco representative, pay a flat $10 shipping fee, and allow 4-6 weeks for your free item(s)!
This is an example of the piston box label you will need to upload a photo of.
The free item options include our new, high-quality modern-fit T-shirts!
Click here to find Wiseco two-stroke pistons for your application!
All Wiseco two-stroke pistons are forged in-house for added strength and durability, and are available for wide variety of applications.
Wiseco Two-Stroke Racer Elite
Wiseco's latest development in two-stroke piston technology is the Two-Stroke Racer Elite piston. These pistons are forged from a 2000 series alloy for additional strength qualities, and protected by Wiseco's ArmorPlating coating on the piston crown and in the ring groove(s) for long-term protection from corrosive combustion chamber conditions.
Watch the video and get the complete details on Two-Stroke Racer Elite HERE.
Some two-stroke pistons require exhaust bridge lubrication holes to be drilled in the piston, and the exhaust bridge on the cylinder to be relieved. Not sure if you need this, or need help completing these tasks? We explain it all HERE.
Do you know the importance of exhaust bridge relief and lubrication holes? Review our full explanation here!
Check out some more of our awesome two-stroke content!
Dirt Bike Mag YZ125 Build 80+ HP Two-Stroke Karts Wiseco Employee-Built 390cc TRX KTM TPi Two-Stroke Pistons What is a Locating Pin? Wiseco "Two-For-Two-Stroke" Rebate Terms & Conditions
Purchase at least $118 worth of any offroad bike or ATV Wiseco two-stroke shelf piston(s) from any dealer or retailer between August 28, 2018 and October 30, 2018 and receive your choice of one out of four available items, or purchase at least $165 under the same stipulations above for your choice of two out of four available items, after online form submission. When applicable, two chosen items must be different, one item cannot be doubled-up. Wiseco two-stroke piston kits and PK kits eligible. Purchased dollar amount minimum must be met completely by Wiseco two-stroke piston product. $10 shipping fee applies to free items. Final shirt and hat colors and designs may not exactly reflect items pictured in promotion images. Promotion does not apply to custom pistons. Minimum purchase amounts at retail value only. Rebate form must be submitted electronically at www.wiseco.com/promo with all required information. Must provide photos or scan of proof of purchase and piston box label showing part number. Allow 4-6 weeks to receive your chosen items. Offer must be redeemed by November 30, 2018.
Offer good only in 48 contiguous states. Limit one rebate per eligible purchase, per household. Maximum number of free items is two. Free gasket kit limited to a retail value of $69.00. P.O. Box address not accepted. Must be 18 years of age. This rebate offer is valid for end consumers only and not available to distributors, dealers, resellers, retailers or e-tailers. Offer void where prohibited, taxed or restricted by law. Please keep a copy of your submission. Substitution of products not valid. Qualifying products cannot be returned to the retailer once the rebate form has been submitted. Offer has no cash value. No substitutions. Void where prohibited by law.
By Dustin Kraus
So having a little issue with my 05 RMZ 450. Just recently did a top end fresh in up on my 450 and now it seems very sluggish and boggs in the low end.It does not have the snap it had before the build. The top end feels great lots of snap and power. So not sure if I have to get the carb tuned or it's something I'm overlooking on my first rebuild. Only got maybe 1 or 2hrs on the build. Any help would be appreciated thanks