1999 Cr270

[Brian1c]

1999 Cr270 poor low end

Hi all. I just had a LA Sleeve 270 big bore kit installed by my local shop since the bottom end on the bike was non existent compared to my 2003 RM250. Got back the bike and I really didnt notice any difference. The thing is a slug to around 4000 rpm (or unless I fan the clutch) whereas my RM raises the front wheel is I breath on the throttle. Any tips on what I could do to wake it up ? It was set up for woods prior. (I have 13/51 gearing; took off the 10 oz weight/checked timing/reshaped head, put on Gnarly pipe). Still playing with the jetting, but this is so far off I'm thinking I need some tips on helping this dog in the 2000-3000 rpm range...I know, sell it and buy a 450 ! it also wont start after riding for 20 minutes.

Let me know if anyone has any fixes...like to steer away from race gas if possible

 

[Backslayer]

first the sleeve was a bad idea but, it still shouldn't be that bad, How is your jetting? Do you have an air leak? done a compression or leak down test on it? those are a few things I would ask myself. Here's a good link on reading plugs for your jetting, old plug is better, start of high and work your way done ie main jet first.

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

 

[Brian1c]

thanks. whats wrong with a sleeve ? I actually dropped it off expecting to get a 285cc LA SLeeve kit installed, but when I picked it up he said they were discontinued and he went ahead and installed the 270cc

 

[Brian1c]

engine also sureges up and down between 3000-4000rpm bothe when riding and at idle

 

[Backslayer]

Sleeve's generally wear out faster wear as nikasil you can get alot more before replate and heat is an issue with sleeve's they tend to run hotter, you have two metals there where the water jacket is will cool faster than the sleeve, not bad though, anyway back to your problems sound like you have an air leak for it to surge like that. or trash in the carb. I would clean the carb, and check your reeds make sure there not fatigued

 

[_JOE_]

The lack of low end, surging and hard starting all could be jetting related. Have you changed anything since the sleeve? Like Backslayer said, check for air leaks too. Make sure the power valve is working correctly, I think the timing is really critical on the crs. Do a search on cr power valves.

 

[Brian1c]

put in new Boysen reeds. The guy at the shop re-checked the power valve clearance /timing etc to make sure it was opening/closing (after I asked about it). I'll ask him about the leak. I'm starting to lose the warm and fuzzies with this guy. I'm hoping jetting is the issue since we bored and changed the pipe. The surging sounded like classic leak to me, but he's had this bike 3x already. I'll let you know when I get it back. (Last time I had an issue, he said it was because it was 45 degrees out ???) Fortunetly it was 53 degrees on Sunday and it started after 5 kicks, but it wouldnt start after running for 20 minutes. Let it sit for an hour, 5 kicks then it started..