Does this look normal? 05 RM 250

Teej317
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Teej317
Edited Date/Time 1/7/2018 11:27am
Picked this smoker up last year and after rebuilding it, I put 13 hrs on it this past summer. Winter is here so looking to do a fresh top end. Does this look normal or do I have bigger issues? Thanks.







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David934
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David934 12/20/2017 12:08am
12/20/2017 12:08am
Looks like on right side inside cylinder scratch. Take off cylinder and check it out properly or take better pictures.
TrailDigger 12/20/2017 4:08am
12/20/2017 4:08am
Looks a little rich.
Acidreamer
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Acidreamer 12/20/2017 6:12am
12/20/2017 6:12am
Looks likes its running rich but not too bad.
Teej317
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Teej317 12/20/2017 10:32am
12/20/2017 10:32am
I ran 32:1 motul 800 at the beginning of season. Noticed it running rich so went to 36:1 and leaned out the air screw a half turn. Spark plug was a nice Golden brown at the tip but a little bit of splooge on the threads. I agree, I could go leaner. Sorry for the bad pics. I will take the piston out and further inspect and clean the cylinder and PV.

The Shop

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ktm-5
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ktm-5 12/20/2017 11:33am
12/20/2017 11:33am
Going from 32:1 to 36:1 is actually making your bike run richer, granted not much but rich and lean does not mean amount of oil. When a bike is rich it is from too much gas to air ratio not oil in the gas ratio
Teej317
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Teej317 12/20/2017 3:27pm
12/20/2017 3:27pm
ktm-5 wrote:
Going from 32:1 to 36:1 is actually making your bike run richer, granted not much but rich and lean does not mean amount of oil. When...
Going from 32:1 to 36:1 is actually making your bike run richer, granted not much but rich and lean does not mean amount of oil. When a bike is rich it is from too much gas to air ratio not oil in the gas ratio
I get that confused. I need to lean out the fuel to air mixture through jetting, not by changing my oil to fuel ratio. I got it...thanks for clarifying.
ktm-5
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ktm-5 12/20/2017 3:32pm
12/20/2017 3:32pm
No problem, a lot of people get it mixed up
oldandslow1
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oldandslow1 12/20/2017 4:46pm
12/20/2017 4:46pm
if i was you i would leave it. any leaner and you are pushing it.
Paw Paw 271
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Paw Paw 271 12/21/2017 8:10am
12/21/2017 8:10am
I would want to see the underside of the piston to make sure it is not a leaking crank seal giving you issues.

Paw Paw
Falcon
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Falcon 12/21/2017 9:58am
12/21/2017 9:58am
ktm-5 wrote:
Going from 32:1 to 36:1 is actually making your bike run richer, granted not much but rich and lean does not mean amount of oil. When...
Going from 32:1 to 36:1 is actually making your bike run richer, granted not much but rich and lean does not mean amount of oil. When a bike is rich it is from too much gas to air ratio not oil in the gas ratio
This.
Also, leaning out the air screw only works in your slow circuit (idle and just above idle at low throttle openings.)
For most riding scenarios, your needle position is what controls the jetting, in combination with the main jet size. I would start by leaning out your needle by a click and see if that gets cleaner. (Move the clip up the needle one position so the needle projects out of the throttle slide farther.)
rob162
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rob162 12/21/2017 7:52pm
12/21/2017 7:52pm
Paw Paw 271 wrote:
I would want to see the underside of the piston to make sure it is not a leaking crank seal giving you issues.

Paw Paw
^^^^ this
Teej317
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Teej317 12/22/2017 11:30am
12/22/2017 11:30am Edited Date/Time 12/22/2017 11:31am
Paw Paw 271 wrote:
I would want to see the underside of the piston to make sure it is not a leaking crank seal giving you issues.

Paw Paw
Pulled the top end off and your suspicion seems correct. Saw some oil under the piston and on the exposed part of the crank. I probably should have done a bottom end rebuild when I first bought it, but everything seemed tight and it ran excellent this summer. Will be doing one now and glad I purchased a crank puller/case splitter last winter. It will be my first experience splitting the cases. Thanks for the help.
Teej317
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Teej317 12/28/2017 3:55pm
12/28/2017 3:55pm
Working on tearing the engine down and ran into some stuck screws. 1) how do i remove these without stripping them? 2) can I replace these with something easier to remove?



Hondas4Life3
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Hondas4Life3 12/28/2017 4:29pm
12/28/2017 4:29pm Edited Date/Time 12/28/2017 4:30pm
Teej317 wrote:
Working on tearing the engine down and ran into some stuck screws. 1) how do i remove these without stripping them? 2) can I replace these...
Working on tearing the engine down and ran into some stuck screws. 1) how do i remove these without stripping them? 2) can I replace these with something easier to remove?



I just ran into this with a RM125. Impact screwdriver is what your supposed to use to remove them. The stripped screws (I had two) I used a Torx bit socket that I hammered into the screw head. They all have blue locktite on them. Heat will help.
Schmidt452
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Schmidt452 12/28/2017 4:46pm
12/28/2017 4:46pm
The clean areas on the piston are called wash, safe wash is 1/4 -1/2 inch. How did the plug look?

A impact screw driver (not a powered on but one you hit with a hammer) will help loosen the screws.

impact driver
Bruneval
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Bruneval 12/28/2017 5:03pm
12/28/2017 5:03pm
Teej317 wrote:
Working on tearing the engine down and ran into some stuck screws. 1) how do i remove these without stripping them? 2) can I replace these...
Working on tearing the engine down and ran into some stuck screws. 1) how do i remove these without stripping them? 2) can I replace these with something easier to remove?



As said above, heat to loosen the loctite and then an impact driver. Key is getting a good fit on the screws before trying to undo, but by the looks of the heads on those, you’re going to need to drill a pilot hole and hammer in a torx bit or use an ‘easy out’ screw extractor.

That said, if you’re just doing main bearings and seals, you don’t actually need to remove either of those parts (powevalve actuator arm and selector paw). Here’s a picture of an RM125 engine I split, where I left the powervalve assembly in place.



Teej317
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Teej317 12/28/2017 5:14pm
12/28/2017 5:14pm
Schmidt452 wrote:
The clean areas on the piston are called wash, safe wash is 1/4 -1/2 inch. How did the plug look? A impact screw driver (not a...
The clean areas on the piston are called wash, safe wash is 1/4 -1/2 inch. How did the plug look?

A impact screw driver (not a powered on but one you hit with a hammer) will help loosen the screws.

impact driver
Plug was golden brown on the tip with some splooge on the threads.
Teej317
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Teej317 1/6/2018 10:20pm
1/6/2018 10:20pm
So I managed to get the cases split and pressed the crank out. As I was getting it out, I heard a little metal piece fall. This is what I found...what did I do? I have no idea what that is...



Pit Row

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FWYT
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FWYT 1/7/2018 8:50am
1/7/2018 8:50am
^^^^^^^^

Looks like a roller bearing cage. Inspect carefully!!!!
Teej317
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Teej317 1/7/2018 11:27am
1/7/2018 11:27am
FWYT wrote:
^^^^^^^^

Looks like a roller bearing cage. Inspect carefully!!!!
That sounds very likely. Will more closely inspect the bearings to confirm. Thanks.

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