Honda Valve Guide Install Questions?

[3 Wheel Drive]

I have been rebuilding an XR100R dirt bike & installed new OEM Honda Valve Guides in the cylinder head. (This is my first time replacing valve guides).

One of the old valve guides was damaged, so I bought 2 new ones. Last night I installed both valve guides & noticed my new valves don’t fit in the guides. (Kibble White Valves) I contacted the eBay seller and asked them why they don’t fit.

The seller told me all new valve guides need to be reamed in order for the new valves to fit.

Do you guys replace valve guides that often? Do you guys drill your valve guides at home or take them to a shop? It would have been much faster and probably cheaper to buy the big valve aftermarket head from Japan....

[BarnBoy]

Maybe dirtcrasher will chime but I believe they have to be driven out and pressed back in. A pita or so ive heard

[shortline10]

Yes the valve guides will need to be reamed / drilled out when you purchase OEM guides , it insures centering of the valve seats . Definitely needs to be done by a machinist with the correct tooling .
I usually purchase aftermarket guides to skip that process .

[El Camexican]

Measure your valve stem and start calling local motorcycle shops to ask if they do head work, or will tell you who does theirs.

I found a VW engine builder here with the right reamer that did my Yamaha, but ended up mailing another head to APE in CA. To have the guides and seats done. It’s not something you want done less than perfect.

[3 Wheel Drive]

I couldn’t find any machine shop that wanted to ream my valve guides. So I ordered myself a 5.5mm reaming bit from Amazon for $7.00. After watching videos on u tube I felt like I could easily drill those very small guides.

It took me just a few minutes to do both. I used some WD40 to lube it up then brake clean to clean it up after I was done. Both valves fit good. I’m going to lap the valves and finish my BBR 120 kit. Also picked up a BBR exhaust pipe!

[ATC King]

At the end of the day, it's a small engine. Not much different from any modern tiller or push mower. Good on you for having a go at it.

[Dirtcrasher]

I was gonna tell you to just buy the reamer.

If you ever need a special reamer, just use Mcmaster/Carr, and you can sometimes buy a "spiral cut" flute reamer that cuts smoother.

There tools are very high quality...

[DOHC_Bikes2]

I like how the tenured members tell you to spend money on parts instead of doing simple work that anyone with hands can do

[El Camexican]

I like how the tenured members tell you to spend money on parts instead of doing simple work that anyone with hands can do

Are you going to enlighten the class with your process, or should we just assume you ream your guides with HSS Tractor Supply drill bits chucked to a second hand cake mixer you picked up at a local yard sale?

Is "tenured" a fancy word you learned in your "special class" for members that don't have to change their user names every few months?

[3 Wheel Drive]

I bought a cheap valve seat grinder and cleaned those up also. It works very good. When my original valve broke it slightly hit the intake valve seat. Now my valves both have a nice tight seal. What a pain in the ass! LOL. After spending all the money on valves, tools and valve guides I could have bought an aftermarket big valve head for less.

It was a learning experience porting the head and rebuilding my first 4 stroke head like this. Time to finish up & ride!

[Yelowfincroaker]

Are you going to enlighten the class with your process, or should we just assume you ream your guides with HSS Tractor Supply drill bits chucked to a second hand cake mixer you picked up at a local yard sale?

Is "tenured" a fancy word you learned in your "special class" for members that don't have to change their user names every few months?

Is ribs pig ?