removing baffel on 97 xr 400

i have just bought a 97 xr 400 in almost showroom condition the bike has about 10 hrs on it. its bone stock by the way. ive read the threds on removing the baffel and snorkel , ind i did so now im reading alittle more and i see some people say that it is dangerous for the carb any one have any prob with the carb after making these mods. oh and by the way what the hell is rejeting?

Jets are precision orifices inside the carb which control the amount of fuel that is mixed into the airflow; they're available in different sizes.

Since an engine is nothing more than an air pump, opening up the exhaust (baffle removal) or the intake (snorkle removal) may (other bikes) or will (xr4) allow the engine to move more air through it.

The amount of fuel in the airstream is critical to performance and engine life; if you make changes which allow more air, you need also to make changes that provide more fuel. This is the typical reason people rejet- it allows the carb to supply the appropriate amount of fuel for the modified air pump.



ps- no danger to the carb, but if you increase the airflow without rejetting you can run into problems from a too-lean condition: overheating, detonation, or total meltdown. Do a search on 'plug reading' to help you figure out if your jetting is lean/rich/or spot on.

I believe the '97 XR400R came with a #60 or #62 pilot jet and a #160 Main jet. Honda assumed that an owner would do what you have done--removed the snorkel and baffle insert, and jetted the bike accordingly. It should be right on. I have a 1998 XR400 and it came with a different jet needle that improves response. I do not have a part no. for it. Maybe some other folks out there will pass that number on.


GlennF is correct. The 1997 XR400 came jetted from the factory for the baffle in the muffler to be removed, as well as the snorkel in the airbox. The jetting is for 2700 feet above sea level.

I live in in Reno NV at around 4700 feet. In the five years that I owned my '97 XR400 I never touched the jetting. I Raced it hard for two years with that stock jetting and exhaust system. Never fowled a plug, never had a problem starting. It still had the original foam air filter when I sold it. :cry:

The only Modification was to the float level in the carburetor. From the factory, the float would not close soon enough and fuel would plug up the air vents making the bike bog momentarily when landing from a jump, or hitting a g-out. I'll try and find the article.

And gregg-usmc, enjoy your 1997 XR400!! :applause::bonk::cry:

hey thanks for the info gents,ive noticed the boging issue as well now ill have to do some float reserch

If you remove the baffle, replace it with a high flow version for the rest of us. There are some really good ones out there. I think the quiet products one is under $50.

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