When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
just wrapped up my spring project and wanted to share with the forum. Almost everything I did was a first and wouldn't have been possible without the info available on this site and I hope to pay it forward and help others along the way! I really fell in love with the "katsumi" look so thats what I went after. i was in complete shock taking if for the first ride, i didn't quite realize the scope of all the changes- its a totally different bike. I absolutely love the bars and suspension (feels a lot closer to my KDX220) and i think i'm going to stretch the gearing out to keep the RPMs down on the road. i have the KDX for my true trail warrior and hope i can be a little lazier with the gearing on the klx with the 351.
posing with my buddies new 501 more glamour with the 501
WARNING: I did not take proper care and clean this machine before tackling the project... i already feel guilty and will do better going forward
wiring up the rear lights. the tail light has an integrated license plate light so i used that line for the vapor power line. (muddy) under view of the new rear fender. using the license plate line to power the vapor. squirrels nest in progress. it was a lot of fun figuring out the wiring. vapor mounted with indicator lights testing. yes, i was sloppy making a hole for the wiring and slipped with the drill scarring the mounting plate.
pretty new rear spring. just happened to match my plastics my right fork was a long time leaker and the seal had to be replaced. i ended up doing both since i put new springs in and added fresh (heavier weight) oil. this was the oil in the leaking fork. totally nasty, and probably 1/4 full. this is what the kerosene looked like after cleaning the leaky fork.... full of nastiness and needed 3 rounds of cleaning to get it to run clear. shiny new cleaned up fork. i ran over them with 1200 grit sand paper to take down any nicks. had a hard time finding a spot to mount the front blinkers so i modified so old brackets i had laying around and hijacked a fork bolt. UFO guards look nice. definitely some weight savings with the new light and vapor. i made a boo boo when setting to TDC; i was 180 off TDC. i had done the MCM mod before so i needed to return the sprockets to the correct mounting holes before adjusting the timing (this is pic is before i corrected everything) found some wear in the cam girdle on the exhaust side. I did a little research on the side and seems like i'm going to open it back up and address whats causing this, that will come next. kind of dirty in here, didn't make me feel too good along with the wear i found with on the girdle. 12k mile OG piston. looks pretty burned to me but i'm not totally sure. success. now comes the hard part (and a beer) those circ pins were almost the death of me, i could have cried. made sure to clean up the mounting surfaces real good and used sealant. compressed rings by hand (after indexing). tried to clean up the head, looks better than it did. i had to re do the cams as mentioned earlier and ended up knocking one of the shims out of place. was able to reset it to get everything seated nicely before triple checking the timing and hand cranking it over probably 10 times.
squeezing the mikuni in there was a total PITA. I was actually able to use my stock throttle cable with these bars (after i paid motion pro to make a 2 inch extended one). She fired right up after assembly and i've been gently riding around for short trips and doing start ups in the driveway, letting it get to temp. No leaks and no explosion! Still messing with the A/F screw and idle settings; i'm in Cali for work now but can't wait to get back home and keep playing! the throttle response is insane with the pumper, i love it. also very happy with the vapor, i got the tach working using the OEM wiring from the analog stocker. i also added the water temp sensor inline and love having an eye on temps with the big bore. cruising around its been holding 170, we'll see how it goes when i start running it hard.
whats next/help needed
break in. my plan was to take it easy with some heat cycling (short rides, varied RPM's, frequent starting and warm ups) for about an hour, change oil (non synthetic) and then ride it like i stole it. too soon?? i couldn't find a consistent process on the forum.
i'm a little Leary on the jetting (M 142.5 P 42.5), i'm scared i'm running lean (getting a lot of popping on decel). i'm practically at sea level, and put my lid back on with the K&N and kdx snorkle per Bills recommendations and the jetting seems like it should be sufficient but i could use some help with that. i haven't ridden it after dialing in the A/F screw but that made the idle much smoother so we'll see if that effects what i am feeling while riding
i haven't gone very hard on the motor and its difficult with the 13 tooth (seems to wind out before i can even get into the thottle much) but i was expecting a little more low end from the big bore after reading about the 1st and 2nd gear power wheelies (i am admittedly one of those guys who can't wheelie at all) and i'm a bigger dude @ 200 lb.
looking into clutch springs in advance of burning up the clutch. i'll try and take it easy for now.
seems like i'll need to address the wear i found on the girdle.didn't do any checking on the valve clearance and i'm not sure if thats related, but happy to hear anything feedback.
swapping in a lithium battery for some additional weight savings.
removing my 13T front sprocket and putting the stocker back on. first gear is useless with the BB. i may go to a 15 to keep it running lower on the road at highway speeds.
thanks all!
Last edited by defenestrate; 06-06-2019 at 05:21 AM.
Reason: added note about LED turn signals and springs
Bike looks great, I like the big headlight set up.
Unless you are getting loud pops, the crackle on decel is not a problem - that is according to Mikuni, not me click here. Throttle closed is a lean condition and unburned fuel collects in the pipe igniting when enough is there, making the crackle. You can go richer on the idle mix to cut it a bit, but that is making the bike run richer than needed. You can also slightly crack the throttle and it will be reduced or go away. My 650 has the crackle and barely opening the throttle stops it, but I don't care since I know it dosn't affect anything.
I know a lot of riders are all about taking off the lid, but no one has any sort of flow documentation. Is the air requirement for the engine greater than the flow allowed by the KDX snorkel? I don't know, what I do know, the cross sectional area of the KDX snorkel is as big as the bell mouth of the carburetor, not the throat, but the bell mouth. It is nearly as large as the air boot between the air box and the carb. That should mean it isn't very restrictive if it is at all. I realize the bend and the shape may have a bit of effect on flow, but the question is if it is enough to cut off the needs of the engine draw through the carburetor on the 250, and I doubt it. The engine can only draw so much air and when the passage is significantly larger than the throat it seems that would no longer be a restrictive spot. I guarantee the OEM snorkel was, though. It was about half the size of the bell mouth area. Removing the lid is just easier and quick to remove the lid.
I did the lid off of my 650, which needs a bigger opening, it had the same snokel as the KDX as OEM equipment, for a half block. It had seriously loud obnoxious intake roar. I pulled the snorkel and cut the opening a bit bigger. Couldn't take the roar, louder than the exhaust. I have no idea how loud the 250 is with the snorkel out, I did the KDX snorkel myself. Had to buy a new one, threw away the 650 snorkel years ago.
Bike looks great, I like the big headlight set up.
Unless you are getting loud pops, the crackle on decel is not a problem - that is according to Mikuni, not me click here. Throttle closed is a lean condition and unburned fuel collects in the pipe igniting when enough is there, making the crackle. You can go richer on the idle mix to cut it a bit, but that is making the bike run richer than needed. You can also slightly crack the throttle and it will be reduced or go away. My 650 has the crackle and barely opening the throttle stops it, but I don't care since I know it dosn't affect anything.
I know a lot of riders are all about taking off the lid, but no one has any sort of flow documentation. Is the air requirement for the engine greater than the flow allowed by the KDX snorkel? I don't know, what I do know, the cross sectional area of the KDX snorkel is as big as the bell mouth of the carburetor, not the throat, but the bell mouth. It is nearly as large as the air boot between the air box and the carb. That should mean it isn't very restrictive if it is at all. I realize the bend and the shape may have a bit of effect on flow, but the question is if it is enough to cut off the needs of the engine draw through the carburetor on the 250, and I doubt it. The engine can only draw so much air and when the passage is significantly larger than the throat it seems that would no longer be a restrictive spot. I guarantee the OEM snorkel was, though. It was about half the size of the bell mouth area. Removing the lid is just easier and quick to remove the lid.
I did the lid off of my 650, which needs a bigger opening, it had the same snokel as the KDX as OEM equipment, for a half block. It had seriously loud obnoxious intake roar. I pulled the snorkel and cut the opening a bit bigger. Couldn't take the roar, louder than the exhaust. I have no idea how loud the 250 is with the snorkel out, I did the KDX snorkel myself. Had to buy a new one, threw away the 650 snorkel years ago.
great thanks for that. I did run lidless before, and could give that a whirl again to see. I have noticed just like you said if i even have a slight crack of the throttle on deceleration, the popping stops. Like i said I will give it a spin when i get home after adjusting the A/F screw. I also have a bit of an exhaust leak at the muffler/header union- the 2 bro's doesn't quite work with the FMF pipe. i previously used silocone to close it up. While i had it apart but this build i actually used a pipe expander to stretch my header pipe a bit to have a better slip in fit but did not apply silicone. i'll button that up too and see if it helps with the backfire.
good work, like the bike! have to done anything with the front forks??
hope you get the wear figured out. what are you using for service intervals? and what kinda oil?
One thing i would do asap is scrap that front brake line. its a rock magnet in stock form.
good work, like the bike! have to done anything with the front forks??
hope you get the wear figured out. what are you using for service intervals? and what kinda oil?
One thing i would do asap is scrap that front brake line. its a rock magnet in stock form.
i bought the bike 2 years ago with just under 12k miles, i've put on roughly 500 so not much. other than changing the oil a couple times i haven't done much service prior to this build. prior to the 351 i was using mobile one but after the big bore installed i put in non synthetic castrol 10w-40. will do the first oil change post BB next week likely after getting some more run time over this weekend.
as far as the front forks, i ditched the old oil (looked like original) replaced the seals, dropped in new springs from cogent and put in heavier weight oil. yeah on the breakline... maybe time to switch to stainless. its a little soft anyway and i could probably use new fluid in the front and rear as a nice refresh.
based on the mileage and what i found during the build i should probably prepare to check valves and other clearances in the top end...
All KLX300Rs and KLX650s run that style brake line. The risk is in crushing the line where it passes under the front axle. Some KLX650 riders did a thing they called "the CR wrap. Here is the diagram to make the line:
06-06-2019, 05:18 AM
'07 overhaul, "katsumi" inspired
Nice!
