My DR650SE is stock. No modifications. I shimmed the main jet needle 0.20 inch and my cruse AFR at 90F on level ground is is 13.5:1 . At 30 mph acceleration to 70mph , wide open throttle the AFR goes to 12:1 then ramps back up to 13.5:1. I'm currently installing a straight through exhaust, no baffles and a high flow air filter. Then I'll need to drill the main jet. Currently when going up a hill the engine is loaded more so the AFR goes from 13.5 to 12:1, depending on how steep the incline is , ambient temperature, moisture in the air, atmospheric pressure/altitude. A rich mix is good for a loaded engine because produces more torque, it burns slower than a lean mix, and the combustion chamber is cooler. This cost me some MPG but my engine loves it. You can't have your cake and eat it to. One must compromise . Borrowing from Peter to pay Paul. More power less mpg.
Just a tip, instead of drilling jets, places like JetsRUs are super cheap to get jets, including smaller increments than stock. I'm unaffiliated, just have used them several times and way cheaper than going to a dealer even if you opt for the name brand jets. I opted for name brand for the 1 pilot jet I needed, then went house brand for main jets, so I could get way more and in in-between steps rather than only getting a few name brand jets. Their house brand are good.
do you still have the cv carb on there?...its nice to see you and your son sharing a passion for the sport!quality time with the kids comes at a premium and life marches on!i wish mine were still young!
I want to set my cruise AFR at 14:1 . I'm not concerned with making a lot of power just want a smooth running engine. What number/size drill bit should I use for stock exhaust, no intake mod either? I hope I get it right the first time. Wish me luck. I may install a free flow glasspack. Not decided yet but if I do what size drill bit would give me a 14:1 cruise AFR?
G'lawd . Guess I wont be attempting this lol drilling jets? I'd be amazed if I could get the carb off change jets and get it back together and working . This is like a manual power commander for carburetors lol I'm going to be saving up for a tm40 pumper.
+Some dude yeah the tm40 is the way to go. but you don't have to drill out the Jets if you have the different sizes. but I didn't have them so I am impatient and i wanted to get it done . lol
+Warren V OOoooooh , roger that . Are you smights dad ?? Nice to meet ya sir . Yea , all the work I've seen done to these stock carbs looks like they can be solved with a mxrob FCR carb or the tm40 . And the FCR from what I've read seems to lower the MPG due to its curve towards performance and the TM40 seems like the happy medium between the underwhelming mega MPG stock DR carb and the blazing performance , tank draining nature of the FCR . But , I must say . If I were to be as impatient as you I would gain a whole new level of technical experience . But seeing as Im a fairly mellow 39yo dude I'll just wait until I can gather enough doll hairs to get the TM40 haha . To be honest , I'll be amazed if I can get the old carb off and do whatever cable mods necessary to get the TM40 fit and running properly :D BTW ya just picked up a new sub for your channel
+Some dude yeah im his dad. nice to meet you also.you did your research on those carbs and your right on track.we were gonna go tm40 but we just have too many bikes to take care of so we have to spread the money out .lol thx for subbing
hey guys,would you guys mind to show/explain the system that you use to talk while riding?it seems pretty hq!it would also be cool for snowmobiling with the wife.
My DR650SE is stock. No modifications. I shimmed the main jet needle 0.20 inch and my cruse AFR at 90F on level ground is is 13.5:1 . At 30 mph acceleration to 70mph , wide open throttle the AFR goes to 12:1 then ramps back up to 13.5:1.
I'm currently installing a straight through exhaust, no baffles and a high flow air filter. Then I'll need to drill the main jet.
Currently when going up a hill the engine is loaded more so the AFR goes from 13.5 to 12:1, depending on how steep the incline is , ambient temperature, moisture in the air, atmospheric pressure/altitude.
A rich mix is good for a loaded engine because produces more torque, it burns slower than a lean mix, and the combustion chamber is cooler. This cost me some MPG but my engine loves it. You can't have your cake and eat it to. One must compromise . Borrowing from Peter to pay Paul. More power less mpg.
Just a tip, instead of drilling jets, places like JetsRUs are super cheap to get jets, including smaller increments than stock.
I'm unaffiliated, just have used them several times and way cheaper than going to a dealer even if you opt for the name brand jets. I opted for name brand for the 1 pilot jet I needed, then went house brand for main jets, so I could get way more and in in-between steps rather than only getting a few name brand jets. Their house brand are good.
Nice. Think this is the route i need to take with my DR350..
do you still have the cv carb on there?...its nice to see you and your son sharing a passion for the sport!quality time with the kids comes at a premium and life marches on!i wish mine were still young!
+hometownguy71 yeah its the stock carb bst40. yeah he is getting married in June so we planned a ride in May before the wedding LOL.
Tkx bro, good infos!!!
I want to set my cruise AFR at 14:1 . I'm not concerned with making a lot of power just want a smooth running engine. What number/size drill bit should I use for stock exhaust, no intake mod either? I hope I get it right the first time. Wish me luck.
I may install a free flow glasspack. Not decided yet but if I do what size drill bit would give me a 14:1 cruise AFR?
very good vid
Thanks for watching!
Hey man, What o2 sensor kit are you using? Im about to do the same thing to my CRF450r Sumo for easier jetting through out the seasons
APSX V2 Anti-Glare D2 Digital Wideband O2 AFR Gauge & Sensor Kit
Your web site link is broke. Do you have a link where to buy the WB kit?
Hey from Norway. How did you isolate each cylinder/ carb during testing and adjustment? You have 4: 1 exhaust?
this is only a one cylinder engine.
What numbers are you shooting for and what were your final jet specs?
I thought you would want to target around 14.7-1 at idle ?
You want idle around 13.5
That O2 is the tool!
+hillbillydualsport yeah it works really well. I have a adapter for the 2 strokes im gonna try.
Its actually pretty genious!
You have link for 2 stroke ?
Nice
G'lawd . Guess I wont be attempting this lol drilling jets? I'd be amazed if I could get the carb off change jets and get it back together and working .
This is like a manual power commander for carburetors lol
I'm going to be saving up for a tm40 pumper.
+Some dude yeah the tm40 is the way to go. but you don't have to drill out the Jets if you have the different sizes. but I didn't have them so I am impatient and i wanted to get it done . lol
+Warren V OOoooooh , roger that . Are you smights dad ?? Nice to meet ya sir .
Yea , all the work I've seen done to these stock carbs looks like they can be solved with a mxrob FCR carb or the tm40 . And the FCR from what I've read seems to lower the MPG due to its curve towards performance and the TM40 seems like the happy medium between the underwhelming mega MPG stock DR carb and the blazing performance , tank draining nature of the FCR .
But , I must say . If I were to be as impatient as you I would gain a whole new level of technical experience . But seeing as Im a fairly mellow 39yo dude I'll just wait until I can gather enough doll hairs to get the TM40 haha .
To be honest , I'll be amazed if I can get the old carb off and do whatever cable mods necessary to get the TM40 fit and running properly :D
BTW ya just picked up a new sub for your channel
+Some dude yeah im his dad. nice to meet you also.you did your research on those carbs and your right on track.we were gonna go tm40 but we just have too many bikes to take care of so we have to spread the money out .lol thx for subbing
hey guys,would you guys mind to show/explain the system that you use to talk while riding?it seems pretty hq!it would also be cool for snowmobiling with the wife.
we use the Sena Smh10
they are really high quality and i cant ride with out it now. I'll see if we can put together a video soon.
ok cool,thanks!
wehn you turn the airscrew to right side close that mean rich air more???
Counterclockwise is rich - Clockwise is lean, on the DRZ fuel screw
leaving a bit lean is OK.... air filter gets clogged up after some riding...so gets more fuel