XR650L hot cams fuel economy / jetting

[gusbratz]

I have a 02 xr650L that I just always rode in the woods till now. The previous owner put a hot cam and Q4 fmf exhaust on it. It has stock gearing 15/45. It runs great, starts in the cold, idles well, no throttle bog. But looks rich by the soot on the muffler outlet and black rear fender. I rode it out to get the title transferred yesterday since I’m putting in on the road to commute to work for the summer. First real “big” trip. About 50 miles there and 50 miles back. I ran 65-75 and pushed it up to 85 a couple times. Got about 35mpg. Is that average for a modified bike at those speeds? Seemed a bit low to me. I was hoping some people with similar mods could chime in. thanks.

[valvesrule]

Mine gets around 35 offroad with Hotcam Wiseco 9-1 piston, Delortto pumper, Supertrapp/10 discs K&N and 15/49 sprockets. Might be it is too rich if you're only getting 35 onroad.

[reduceus]

I would suggest that you give it a good ride - stop the engine quickly and remove the spark plug (you may have to wait a while to let it cool down unless you have heat resistant hands - that will tell you exactly how the engine is running. The following link may help http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html

[ScottRNelson]

Mine gets about 35 mpg with a stock engine, but opened airbox, jetting and a pipe.

All of the bikes I've owned recently get about 35 mpg for most riding. The Ducati ST2 could hit 50 on a long trip, but all other riding was 35. I think my KTM is more like 32.

I ride for run rather than fuel economy, so I just accept it.

[SALTY94XR650L]

My 94L gets 40-42.....I have a Hot cam stage 1, bored 3 times with high comp piston 10.5 I think, "STOCK CARB" FMF power bomb and super trap -4" Gears are 16/39 highway and 16/45 dirt

Jets are 58/175 but going to go to 180...Rode with two other 650L's and two R's and they were the same as mine and all burnt the same amount of oil, that was on a 600mile trip in Baja, mainly on the tierra.. My bike is also not for show --I ride hard..only drowned it three times crossing flooded areas,

 

ya yours could do better, I run 91 octain or better

[SALTY94XR650L]

oooops it was a 15 front sprocket

[brianhare]

14/48.........Megacycle Cam,,11.25-1 JE, FCR MX and fifth overdrive and alot of other mods.......mixture of 60% or better offroad 40% on.........i get 50-55 mpg.........ThumpNRED gets about the same with the FCR MX.......i`m a little rich i think.....

 

Even with the stock carb i never had that low......most people jet these way too rich to keep engine temps down....with the CV carb i had to go down to 52/155 to get the plug a decent color......

 

B