400ex exhaust upgrade ?

My son just got a 400ex. I have no experience with the sport bikes. (Neither does he.) He replaced the stock muffler with an HMF. He’s being told that the carb will need to be re-jetted. So, does it need re-jetted and if so, what are your recommendations?

Big Red 250 1988

Hi all,
Joined forum for some help please.

Need a CDI for the above Quad and the only number/letters on the unit are:
HC4 C1545A

I can find plenty that look physically the same but with a different code. It seems they are not interchangable , could anyone advise a compatible part or any advice please.

Thank you.

Big Red 250 1988

Hi all,
Joined forum for some help please.

Need a CDI for the above Quad and the only number/letters on the unit are:
HC4 C1545A

I can find plenty that look physically the same but with a different code. It seems they are not interchangable , could anyone advise a compatible part or any advice please.

Thank you.

2013 Yamaha Grizzly 700 is acting

Ok Friday night we started riding the grizzly and road it all weekend long with no problems at all. Sunday morning it decided to loose power, spit and sputter, and backfire. I wasn’t able to get above 15mph. Normally we run non-ethanol fuel in all our bikes, but I was unable to find it so I got 93 octane. Could it be the fuel? Does it have a limp mode if so how do I get it ou?

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