OEM part required 1 class
Y.4.1 keeps the original control unit, which on a two-stroke entry is the CDI box, and allows it only to be reprogrammed with no input, output or sensor added, so an aftermarket CDI is not legal here. · Y.4.1
IHRA · Ignition
Aftermarket CDI ignition (2-stroke), IHRA
IHRA answers this part for 15 of its classes. 3 of those answers permit the part outright and 7 permit it with stated conditions, leaving 5 that do not. 2 of the ones that do not are classes we read as open rather than as refusing it. 3 are inferred from how the class is written rather than quoted from a rule naming this part.
This page is IHRA only, and the bodies do not agree. The same part under IJSBA. Which one applies to you is decided by whoever sanctions the race you enter.
Where it stands, class by class
15 classes, grouped where the same rule gives the same answer rather than listed one by one, because an answer that holds for a class usually holds for every class that borrows its rules.
What each answer below means
- OEM part required
- This comes off. Only the part the manufacturer fitted is allowed here.
- Not permitted, not listed in the rules
- Treat it as coming off. The class requires the craft to stay stock except where the rules allow otherwise, and this part is not on the list, so this is our reading rather than a rule we can quote at you.
- Legal, with conditions
- Keep it, but measure it: the rules permit this part only inside stated limits.
- Legal
- Keep it. The rules permit this part in this class.
- No rule, this is an open class
- Probably keep it. The class carries no stock clause at all, so anything unlisted appears to be open. The rulebook does not say so in terms, and this is our reading rather than a permission anybody wrote down.
OEM part required 1 class
Z.7.1 lets a two-stroke entry's control unit, its CDI box, be modified with no input or output added, but names no aftermarket unit, so the original box stays. · J.1, Z.7.1
Not permitted, not listed in the rules 1 class
DD.7 states no engine type, so a two-stroke entry cannot be ruled out, and DD.7 does not list this part, so under the DD preamble it is not legal on either engine. · DD.7
Legal, with conditions 1 class
Ski Lites admits only the two-stroke SX-R 800 and SuperJet, whose electronic control unit is the CDI box, so O.4.1 lets it be modified or replaced with an aftermarket unit, with no sensor added. · O.1, O.4.1
Legal, with conditions 1 class
Yamaha CDI aftermarket allowed if timing cannot be manually adjusted; Yamaha units NOT using 760 cylinders may use programmable ignition. Kawasaki Gen2 (2005-2007) CDI may be programmable. Original charging systems required. Timing may not be advanced at the stator plate. · U.4.1
Legal, with conditions 1 class
ECU/CDI may be modified or aftermarket and may carry a programming port, with no additional inputs, outputs or sensors, and a replacement unit uses the original factory connections (M.5). A Yamaha SuperJet on the 701 cylinder must keep the OEM CDI and CDI box; on the 760 cylinder an aftermarket CDI box is allowed (M.6.2.1.2). · M.5, M.6.2.1.2
Legal, with conditions 1 class
On a two-stroke entry P.2.5 lets the CDI unit be modified or replaced with an aftermarket unit and the RPM limiter be bypassed or removed, while the original charging system must stay, and the Ski Lites rule carried in by P.2 adds that no sensor may be added. · O.4.1, P.2.5
Legal, with conditions 1 class
Two-stroke entries: RPM limiter may be bypassed. Original charging system must remain. · BB.8.1
Legal, with conditions 1 class
The CDI unit may be aftermarket or modified and the RPM limiter bypassed or removed, and as the class's control unit it may not exceed the original unit's capabilities, must use the original connectors and takes no added sensor or input. · T.4.1, T.4.2
Legal, with conditions 1 class
Vintage Ski admits two-stroke craft, whose control unit is the CDI box, so S.4.1 lets it be aftermarket with no input or output beyond the original and no sensor added, while S.4.2 opens the rest of the ignition system, the RPM limiter bypass and total-loss ignition included. · S.4.1, S.4.2
Legal 1 class
The ignition system and electrical box that house a two-stroke CDI may be modified or replaced with aftermarket components, and V.7.1 also allows an aftermarket ignition system in place of the ECU. · V.7.1, V.7.2
Legal 1 class
DD.12 permits an aftermarket ECU in a class open only to two-stroke craft, whose control unit is the CDI box, so an aftermarket CDI is allowed in terms. · DD.12
Legal 1 class
DD.10 permits an aftermarket ECU, and on a two-stroke entry that unit is the CDI box, so an aftermarket CDI is allowed in terms. · DD.10
No rule, this is an open class 1 class
No restriction in section CC, and CC.1 permits any modification it does not restrict.
- Freestyle · CC
No rule, this is an open class 1 class
The class states only what it bans and calls itself run what you brung, against a section DD preamble that says anything unlisted is illegal.
- Drag, Unlimited · DD.6
Aftermarket CDI ignition (2-stroke): if the rule your class applies reads differently to you, or the rulebook has changed since this was read, ask. We answer with the section we read it from, or that we have not read it. Ask a rules question.
Every IHRA class · where the rulebooks differ · checks on parts the shop sells · how this site reads a rulebook.
Ignition · two stroke · legal in 10 of 15 answered, 7 with conditions