XR650L rod movement question (+ advice on parts to replace during complete teardown)

Hey all,

Got my XRL apart and am waiting for hot cam, 10.5:1 piston, and time to put in my new transmission. I'll be splitting the cases this week.

Question is this, before I re-assemble, I'm trying to get a sense of whether or not any of my bearings need replaced.

Mainly I want to know how much side to side movement I should see when I grab the piston end of the rod and move it side to side?

Also, is there anything else I should look for before re-assembling this engine? Any common weaknesses I should know of? Any other parts I should install at this point while I've got the engine 100% torn down?

Hey all,

Got my XRL apart and am waiting for hot cam, 10.5:1 piston, and time to put in my new transmission. I'll be splitting the cases this week.

Question is this, before I re-assemble, I'm trying to get a sense of whether or not any of my bearings need replaced.

Mainly I want to know how much side to side movement I should see when I grab the piston end of the rod and move it side to side?

Also, is there anything else I should look for before re-assembling this engine? Any common weaknesses I should know of? Any other parts I should install at this point while I've got the engine 100% torn down?

there will be some side play, just no up and down. not sure of the spec., do you have a manual?

look into the case and look at the trans. gear surfaces. especially 3rd. they should be smooth with NO pitting. if there is pitting, replace the gears.

let us know the power difference when done. i want to do this to my xrl. what carb you run? any exhaust?

When I complete this project next month here's what I'll have in my '93 XR650L at 3000'

-2000 transmission

-stock carb with:

shim: .05"

5/32 holes drilled

3 1/8 turns out on air screw

165 main jet

52 pilot jet

-K&N pod filter

-White Bros header

-Supertrapp IDS2 with 12 plates

-Lightly ported/matched head

-101mm 10.5:1 JE piston

-hot cam stage 1

I'm guessing that the stock carb won't be ideal for this setup. I anticipate needing / getting the FCR pumper this winter.

55RWHP here I come!:thumbsup:

When I complete this project next month here's what I'll have in my '93 XR650L at 3000'

-2000 transmission

-stock carb with:

shim: .05"

5/32 holes drilled

3 1/8 turns out on air screw

165 main jet

52 pilot jet

-K&N pod filter

-White Bros header

-Supertrapp IDS2 with 12 plates

-Lightly ported/matched head

-101mm 10.5:1 JE piston

-hot cam stage 1

I'm guessing that the stock carb won't be ideal for this setup. I anticipate needing / getting the FCR pumper this winter.

55RWHP here I come!:thumbsup:

that looks really good! fire breathin' porker! i use a fcr41 i bought from sudco. love it! killer response. let us know he she runs when done. get er dyno'd too.

I just checked the specs and it looks like I'm good.

On another note, there was bit of slack in the old piston pin to rod clearance, but it appears that the new pin will tidy a lot of that up. Might explain a bit of the noise I got at idle...

Thanks for the input!

oh yeah, piston pin play will make a nice upper end noise. just make sure the upper end rod bushing/bearing is in good condition.

On that note, the tolerance between the new piston pin and old rod is .0001" over the max of it's limit. It is actually at 0.002" instead of the 0.0019" max listed in the manual. The service limit is listed as being WAY more than that...

Do you think I need to spend the extra couple hundred bucks on a new rod? I am going to be seeing somewhere around 50HP, but I don't want to break the bank unnecessarily...:thumbsup:

On that note, the tolerance between the new piston pin and old rod is .0001" over the max of it's limit. It is actually at 0.002" instead of the 0.0019" max listed in the manual. The service limit is listed as being WAY more than that...

Do you think I need to spend the extra couple hundred bucks on a new rod? I am going to be seeing somewhere around 50HP, but I don't want to break the bank unnecessarily...:thumbsup:

thats going to be a judgement call. a tough one. unfortunately those specs are set at a specific number for a reason. also being at around 50hp... man i'd like to see some other opinions.

how are you measuring the inside of the rod? you are talking outside of piston pin and inside of rod right?

yup. Engine's apart. Calipers inside small rod hole, calipers outside new rod pin, subtract = .002"

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