Talk to a performance expert
mon-thurs 9-5 cst
Inlet spring shims allow micro-adjustments to pop-off pressure. Shims are installed under the inlet tension springs to change the spring install height. The change in install height will increase the spring pressure and pop-off pressure of the carburetor. Pop-Off Pressure is not a fuel pressure adjustment but does affect fuel volume primarily at low speeds. Pop-Off Pressure will also affect how easily the engine can cold start.
Returns- Returns must be communicated by customers within 7 days of delivery and sent back within 30 days to receive a refund. No returns without authorization will be accepted. All returns must be accompanied by a copy of the receipt and a note. All items must be returned complete and in new condition.
All returns are subjected to 20% processing and restocking charge after the product has been inspected. The shipping cost will not be refunded.
Refunds will be made back to the same method of payment when ordering those parts. We will not refund a different method of payment.
Non-returnable Items Include- Close Outs and Clearance Items, Special Orders, Custom Orders, Used Parts, and Cut to Length Items. (Other items may apply)
Shipping: All orders are shipped UPS Ground, UPS Surepost or USPS Priority when ordering online. Shipping charges are calculated based on weight, size, and quantity of boxes in addition to processing and handling including insurance. All shipping charges are the customer's responsibility (even if charges online are not the same as emailed or phone orders).
All standard shipping orders will be shipped within a day or two on weekdays. Orders placed on the weekend (Fri-Sun) will be shipped Monday or Tuesday or the first weekday after a holiday. Custom or Handbuilt Products may require more time to be built before shipping. For any reason, an order may be delayed or prevented you will be contacted through phone and/or email.
Express/2nd Day/Next Day Shipments: Express orders must be made by phone orders only! Orders placed after 12:00 p.m. CST. will be processed the Next Business Day. UPS will only guarantee next day shipment. If you choose 2nd-day shipments expecting it before the weekend, UPS does not guarantee its arrival
Additional Fees: Double Check that the address you gave is correct. You may be charged additional fees to redirect your package to the correct address.
PO Boxes: We can ship to PO Boxes using USPS. However, UPS will only accept shipments to a valid street address. They do not deliver to P.O. Boxes.
International Shipping: International buyers are responsible for paying duties, taxes, and applicable customs brokerage fees separate from the merchandise cost. Buyers will generally pay these fees upon receipt of your shipment. Buyers may be charged additional fees once they receive the package. Read our international policy here.
Paypal: All orders paid by a verified PayPal account will be shipped to the address on the Paypal account to comply with Paypal's policy. No Exceptions.
UPS Estimated Shipping Lead Times
USPS Estimated Shipping Lead Times