Could you check my re-shim calculations?

-----------Feeler---Old shim (inch)---Old shim (mm)---New Shim (mm)

L exhaust--.009-------.095"-------------2.413------------2.150

L intake----.003-------.075"-------------1.9049999-------1.775

Thanks guys/gals.

-----------Feeler---Old shim (inch)---Old shim (mm)---New Shim (mm)

L exhaust--.009-------.095"-------------2.413------------2.150

L intake----.003-------.075"-------------1.9049999-------1.775

Thanks guys/gals.

I checked your calculations using Heckler's spreadsheet (see thread above) and came up with the following:

L exhaust, new shim = 2.36

L intake, new shim = 1.85

I double checked - but you should do it yourself and then re-measure after you've put it all back together, just to be sure.

L exhaust, new shim = 2.36

That sounds much better (not saying it's correct), but if the shim change drops from a 2.413 to a 2.15, that's a 0.263 drop.... anything at or more than .2 lower than factory it's time to consider a valve job.

I just put in his calulation (in the spreadsheet) and for the exhaust it looks like he went to the closet one up rather than down if he goes down then he would have 2.125.

The only way I got 2.36 is by placing in "2.63" for the old shim in mm. Which gave me 2.359.

I have not heard the .263 drop means revalve time...where did you see that? Its an interesting peice of info...Thanks

The intake looks correct.

I have not heard the .263 drop means revalve time...where did you see that? Its an interesting peice of info...ThanksQUOTE]

A .263 change in the valve stem length is a huge change and probably indicates imminent failure. By my calculations (using the spreadsheet) to get a .263 change in shim size would take more than a .008 change in the valve stem length - which is roughly equivalent to going from .010 to .002 on an exhaust valve - a sure sign of trouble.

I doubled checked my calculations again - I'm still showing 2.36 for the new exhaust shim (this is a relatively small change in shim size - which you would expect given that the exhaust valve is only nominal off of spec - .010).

-----------Feeler---Old shim (inch)---Old shim (mm)---New Shim (mm)

L exhaust--.009-------.095"-------------2.413------------2.150

L intake----.003-------.075"-------------1.9049999-------1.775

Thanks guys/gals.

I don't know where you got your exhaust shim size from but there isn't any 2.413

Was it 2.40 or 2.425?

As far as the intake you would need a 1.85

the way I got the same 2.413 was when i coverted .095" to mm when i checked his calculations. I am pretty sure that he does not mean that was what was written on the old shim.

the way I got the same answers as him when i looked at this (using the spreadsheet) was by tossing in the feeler number into the first cell in "Measured Clearence:" then in the second cell I placed in the "Old shim (mm)" into "Measured Old Shim:" which does result in the numbers he posted.

And for the final (new shim) I think he looked for the closest number (up or down) to what he got in "New Shim Size:"

not saying this is correct but i am pretty sure that is how he came to his results.

*Just read my PM's and he mentioned that he replaced a camshaft with (not sure what hotcams or R model or some other brand) he also mentioned that the valves were perfect prior to the cam install and after before 'break-in'....just some more FYI

Did you convert your feeler measurement to mm using the center box in the spreadsheet?

The number printed on the shim should be reliable - unless your shim has worn a lot, but then you (probably) wouldn't be able to read the number anyway.

The cam shouldn't matter.

.0955" would be a 2.425mm shim. So, you would need a 2.375 shim.

I use the actual Honda shim sizes and count up or down whichever way I need to go. Each shim size is .001"

This is for the 450 so the part #'s are different but the sizes are the same.

14901-MBB-000 .0472in 1.20mm

14902-MBB-000 .0482in 1.225mm

14903-MBB-000 .0492in 1.25mm

14904-MBB-000 .0502in 1.275mm

14905-MBB-000 .0512in 1.30mm

14906-MBB-000 .0522in 1.325mm

14907-MBB-000 .0531in 1.35mm

14908-MBB-000 .0541in 1.375mm

14909-MBB-000 .0551in 1.40mm

14910-MBB-000 .0561in 1.425mm

14911-MBB-000 .0571in 1.45mm

14912-MBB-000 .0581in 1.475mm

14913-MBB-000 .0591in 1.50mm

14914-MBB-000 .0600in 1.525mm

14915-MBB-000 .0610in 1.55mm

14916-MBB-000 .0620in 1.575mm

14917-MBB-000 .0630in 1.60mm

14918-MBB-000 .0640in 1.625mm

14919-MBB-000 .0650in 1.65mm

14920-MBB-000 .0659in 1.675mm

14921-MBB-000 .0669in 1.70mm

14922-MBB-000 .0679in 1.725mm

14923-MBB-000 .0689in 1.75mm

14924-MBB-000 .0699in 1.775mm

14925-MBB-000 .0709in 1.80mm

14926-MBB-000 .0719in 1.825mm

14927-MBB-000 .0728in 1.85mm

14928-MBB-000 .0738in 1.875mm

14929-MBB-000 .0748in 1.90mm

14930-MBB-000 .0758in 1.925mm

14931-MBB-000 .0768in 1.95mm

14932-MBB-000 .0778in 1.975mm

14933-MBB-000 .0787in 2.00mm

14934-MBB-000 .0797in 2.025mm

14935-MBB-000 .0807in 2.05mm

14936-MBB-000 .0817in 2.075mm

14937-MBB-000 .0827in 2.10mm

14938-MBB-000 .0837in 2.125mm

14939-MBB-000 .0846in 2.15mm

14940-MBB-000 .0856in 2.175mm

14941-MBB-000 .0866in 2.20mm

14942-MBB-000 .0876in 2.225mm

14943-MBB-000 .0886in 2.25mm

14944-MBB-000 .0896in 2.275mm

14945-MBB-000 .0906in 2.30mm

14946-MBB-000 .0915in 2.325mm

14947-MBB-000 .0925in 2.35mm

14948-MBB-000 .0935in 2.375mm

14949-MBB-000 .0945in 2.40mm

14950-MBB-000 .0955in 2.425mm

14951-MBB-000 .0965in 2.45mm

14952-MEB-000 .0974in 2.475mm

14953-MEB-000 .0984in 2.50mm

14954-MEB-000 .0994in 2.525mm

14955-MEB-000 .1004in 2.55mm

14956-MEB-000 .1014in 2.575mm

14957-MEB-000 .1024in 2.60mm

14958-MEB-000 .1033in 2.625mm

14959-MEB-000 .1043in 2.65mm

14960-MEB-000 .1053in 2.675mm

14961-MEB-000 .1063in 2.70mm

14962-MEB-000 .1073in 2.725mm

14963-MEB-000 .1083in 2.75mm

14964-MEB-000 .1093in 2.775mm

14965-MEB-000 .1102in 2.80mm

14966-MEB-000 .1112in 2.825mm

14967-MEB-000 .1122in 2.85mm

14968-MEB-000 .1132in 2.875mm

14969-MEB-000 .1142in 2.90mm

14970-MEB-000 .1152in 2.925mm

14971-MEB-000 .1161in 2.95mm

14972-MEB-000 .1171in 2.975mm

14973-MEB-000 .1181in 3.00mm

These are all the valve shims available for the CRF. The shims are marked in mm but they are rounded to three digits: 1.825mm is acutally 182 on the shim and 1.875mm would be marked 188. As far as the measurements in inches, I carried them out four places. If I would have rounded them, you end up with two different shims with the same english measurement. Must be the shift between the two standards I guess. RR.

Did you convert your feeler measurement to mm using the center box in the spreadsheet?

I dont think feelers come in inches but i do know mine are "mm" maybe his are inch...dunno

.009 needs to be converted to .2286 before entering it in the spreadsheet to produce meaningful results - IMO

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Connor Wright
      Hey I have a crf250x 2005 I was riding today in top gear flat out and when I slowed down blue smoke just poured out the exsaughst then I happened to open the air box lid and saw it has what looked like engine oil in it then took out air filter and noticed that there was splatters of engine oil on the inside and that and the channel that goes to the carby had engine oil all over it.
      Also bike got a top end rebuild 15 hours ago
      The engine still runs good and sounds normal
      why would this be happening on a resonabley fresh engine
    • By mikemcbride
      Hey everybody. Quick question for y'all. I recently went riding and about halfway through my ride my motor seized on my '07 CRF250X. I haven't investigated it much but I checked the oil when I got home and there basically was none so I'm assuming that was the culprit. There weren't any metal shavings in the filter or on the plug either. At this point I'm trying to decide to rebuild the motor or just sell the bike as is and let the next buyer deal with it (they would know the deal obviously.) I feel that I'm pretty mechanically inclined but rebuilding a CRF engine is a bit out of my league and I assume paying a shop to do it would put me out more money than the bike is worth. So, I have this question to ask; what would be a fair price for a pretty dang nice shape 07 CRF250X, with a seized motor with an unknown extent of internal damage?
    • By ThomasM.
      selling Hot Cams Valve Shim Kit that i bought for my 2005 crf250x, will also fit crf250r.
      used 1x 1.30 and 2x 1.55 shims. the rest is still there.
      $60usd shipped in the usa or canada
      please contact me for pictures or if you are not sure if it will fit your bike
    • By TerryA
      I have two rides in on my new Rekluse auto clutch and I have to say I'm very pleased. The install wasn't hard, but was pretty much a all afternoon sort of project. I also installed a left hand rear brake kit and a two finger cluth over-ride with the adjuster on the perch (which I rarely seem to need). It has all worked great right from the beginning. After struggling to get up a tricky hill in first gear, I tried it in second and the autoclutch helped me clean the hill easily. Not having to worry about clutch action in techinical sessions has also eased fatigue and just made it more fun all the way around. I ride mountain bikes alot, and having both brakes up on the bars has also been nice as it makes for a set-up just like the bicycle - in fact I like that as much as not having to worry about clutch manipulation. The brake on the bar is especially nice on tricky downhill sections where you need to paddle, such as nasty rock/rut stuff. So first impressions are that it was worth the investment -making the ride more enjoyable and easier at the same time!
    • By Mikey560
      I was driving the bike for 15min or so and all of the sudden the bike stalled. I tried starting it again with no luck. I took the spark plug out to see if there is spark so i ground the spark plug to the frame and there is no spark. I even put a new spark plug in the bike and still nothing. Any ideas what i should check??