I have a '97 XR400 that's got some old gas in it... any tips on cleaning out the carburetor? What seals should I order from Honda?

Thanks!

SupraTuRD :ride:

SupraTuRD said:

The repair manual shows what s/b replaced when doing a carb tear-down cleaning. Maybe someone here has specifics if you don't have the manual. Several O-rings & a gasket or two. Carb cleaners WILL destroy O-rings btw.

Thanks XR Bill! I have the Clymer's manual and just found the exploded view of the carb.

BTW, is the OE manual worth getting? I've never been a big fan of aftermarket manuals such as haynes and chiltons (for cars anyway).

Yes, the OE manual is very good, especially if you can pick one up on ebay for $15-$20. New price is a bit too high though at about $50.

I have a '97 XR400 and have to go through the same carb cleaning ritual if the bike has been sitting 4-6 months. Definitely change the gas out with new. These carbs are very sensitive to gumming up the low speed pilot circuit and become impossible to start and stay running. A good carb dip, the 1 gallon can with the basket for soaking type, works great. Take the float bowl off and remove the floats and take all the jets out. Put the jets in the carb dip and the upper carb body with the top half sticking out of the dip. Only the lower half needs a soaking. You should not need any rebuild parts unless one of the seals looks bad. Soak for no more than twenty minutes and flush thoroughly with water and blow of with an air hose. Put it back together and it should be good to go. I've tried carb sprays before and had no luck at all but the dip gets the goo out of the small passageways very nicely.

One more thing on the '97 XR400. There was a batch of them, about a three month run, that had un-heat treated valve adjuster stems. Mine was one of them. If your valves need constant adjustment to keep the clatter down then you probably have one too. New valve stem adjusters are only around $30 for all four and fit all years XR400.

SupraTuRD said:

I hear ya on the after market manuals. I have the Clymer in addition to the factory repair manual. My take is it's always good to have 2 references, since one is rarely 100% clear on many procedures / specs. I bought the factory manual on ebay or amazon for pretty reasonable - like $20. Always good to have the factory manual.

Here's a link

Do a search it's on here somewhere. I used it this week in fact.

KrAzyOSUcoWboY said:

Yup, forgot about that.

http://www.theventur...04%20XR400R.pdf

Here's a quickie cleanup job that works well. Drain the float bowl, remove the fuel line from the carb and fill the bowl with carb cleaner. Replace the fuel line and run the engine. Repeat the process a couple of times if necessary.

XR Bill said:

I've been lucky, I usually gently pull out the oring and get away with re-using it, at least so far. I just pull the carb out and soak the jets, and then make sure the jet holes are clean. Sometimes I use a bread tie wire to ream out the jets a tad when I can tell the buildup is not disolving.

This is usually on somebody else's bike, or a bike I've just bought. I make sure to run my bike at least every few weeks, or I run it with stable in it if it's going to sit for more than a month or so.

I forgot to mention, I think the BEST way to clean your carb, is to remove it, call XRsonly, and order a pumper, replace yours with the pumper, and then keep yours to put back on the bike when you sell it. Then, you can sell the pumper on ebay for about 100 less than you paid for it. You'll easily get 100 bucks in smiles out of that carb. JMO, some guys think a properly jetted stocker is great, but I really find the pumper to be far superior. My bike starts first kick with a pumper, now so even after a fall. That would never happen with a stock carb, even jetted and opened up. Again, JMO and just my experience.

sbabs said:

Agree 100%! Simply installing a pumper carb ( I prefer Edelbrock) really wakes up a stock XR400, the difference is huge.

What is the difference in the operation of the stock and the pumper carbs

Almost anything is better then stock but the 36mm pumper really is too small.

marc9677 said:

The stock is just prehistoric. Honda should be ashamed for installing such a relic. It's just old-school tech that leaves the low-mid feeling flat. This engine can explode with power in comparison with a proper carb like a pumper or BST/BSR that will feed it properly. IMO the 36mm pumper kit is too much money for what you get, especially if you plan on mods.