KLX 250 ( 300 ) camshaft mod by Marcelino
#961
Not knocking the cam mod, just didn't work out for me. Wouldn;t read too much into my dyno posting or it's jetting, bike was a few rides new, had restrictive over oiled stock filter still in it and a pretty heavy trials tire on the back, stock gearing. After that a K&N filter lid off and bigger main and a big gun pipe made it run better yet but I didn't re dyno it. Got tired of the lid off airbox noise, and loud pipe on long rides so went back. Have other bikes to ride with more performance so lost interest in trying to squeeze it out of the klx. Why I don't visit here much, but when I do I like to check in on the cam mod to see if anyone's made new progress. On the KLR forums omeone suggested an ex cam retime to squar up the lobe centers , made sense so I tried it. Didn't like that either, ran better with kawasakis goofy timing.
#962
So the Ex only didn't work out. That was gonna be my next question..
In recent years, there was another member tuning for top-end power that thought the MCM muted it - he put it back as well.. So you have company in that assessment.
In recent years, there was another member tuning for top-end power that thought the MCM muted it - he put it back as well.. So you have company in that assessment.
Last edited by Klxster; 07-09-2016 at 03:34 AM.
#963
just did the mod and found the bike to pull better all round and with the ACR disabled it starts a treat even warm
starting the bike now the starter now just says "AHEM" and off it goes into idle
starting the bike now the starter now just says "AHEM" and off it goes into idle
Last edited by peabrain; 07-16-2016 at 12:37 PM.
#964
This weekend i got to give the bike the first good test after the mod and here is how it went
Rider specs
About 180 cm high
107 kg in gym gear
On bike i had some soft panniers 2x 27L with about 10kg of clothes and electronics
Results
Fuel economy
Trip 1
Tank 1 going to highway 10% city 30% main road 60% highway = 25,6 km/l
45-70 mph (speedo)
Tank 2 95% freeway 5% city = 27,6 km/l
did not go easy on throttle overtaking a good amount of trucks and campervans
55-75mph (speedo)
Trip 2
Tank 1 95% highway 5% city = 30,2 km/l
just taking it easy 60-65mph (GPS)
Tank 2 60% highway 35% main road 5% city = 25,5
going about 75 mph (gps) overtaking a lot on highway (GPS)
Top speed was about 81 MPH not bad considering rider weight and panniers
did not try hard
(reason could feel something holding the bike back a lot possible exhaust and fueling)
Conclusion
this MOD helped my fuel economy a little since i now have to give less throttle to maintain the same speed.
after having been on the highway i can tell that a less restrictive exhaust is going on my list, as i am running the EU stock with catalytic converter and it is restricting a lot after 65 mph.
A re-flash of ecu is also on my list to get better fueling.
i may also remove the lid on the airfilter box if confirmed it will help better then running with no snorkel
and finally i a going to get the 3 gal tank for better range 125-150 km is to damn short
all in all i think this MOD is well worth it alone even alone without doing above written items.
Rider specs
About 180 cm high
107 kg in gym gear
On bike i had some soft panniers 2x 27L with about 10kg of clothes and electronics
Results
Fuel economy
Trip 1
Tank 1 going to highway 10% city 30% main road 60% highway = 25,6 km/l
45-70 mph (speedo)
Tank 2 95% freeway 5% city = 27,6 km/l
did not go easy on throttle overtaking a good amount of trucks and campervans
55-75mph (speedo)
Trip 2
Tank 1 95% highway 5% city = 30,2 km/l
just taking it easy 60-65mph (GPS)
Tank 2 60% highway 35% main road 5% city = 25,5
going about 75 mph (gps) overtaking a lot on highway (GPS)
Top speed was about 81 MPH not bad considering rider weight and panniers
did not try hard
(reason could feel something holding the bike back a lot possible exhaust and fueling)
Conclusion
this MOD helped my fuel economy a little since i now have to give less throttle to maintain the same speed.
after having been on the highway i can tell that a less restrictive exhaust is going on my list, as i am running the EU stock with catalytic converter and it is restricting a lot after 65 mph.
A re-flash of ecu is also on my list to get better fueling.
i may also remove the lid on the airfilter box if confirmed it will help better then running with no snorkel
and finally i a going to get the 3 gal tank for better range 125-150 km is to damn short
all in all i think this MOD is well worth it alone even alone without doing above written items.
Last edited by peabrain; 07-24-2016 at 03:43 PM.
#965
Update: Finally we have the Dyno charts to show MCM differences - Significant TRQ increases 3000 to 6500 rpm, with a slight loss above (max loss is approx .75 lb ft TRQ), vs stock timings.. Note that this loss could easily be considered within the margin of error considering how this data/comparison was accomplished. This is with stock header + Lidless airbox + Lidless CVK setup (DJ140/1N) .... https://www.kawasakiforums.com/forum...timings-44296/
Last edited by Klxster; 06-06-2018 at 01:54 PM.
#967
Well, at least this video mentions that you have to move/rotate the gear 2 links toward the right (which is the direction of "advancement") before reconnecting it to the Ex. cam using the "int" holes.. I watched carefully and still did not identify the 2 link gear advancement prior to cam reattachment.. Oh well, he's a magician..
Now - for those of you that want to try this "1/2 MCM" at home - This vid leaves out/makes no mention of the fact that the KACR must be deactivated. It is the device on the other end of the Ex. cam, and you must pull the little spring off of it to deactivate it.
Why those idiots failed to mention this extremely important part of the MCM is beyond me.. Your KLX won't start when warm/hot until you manage to pull the spring off the KACR !
Now - for those of you that want to try this "1/2 MCM" at home - This vid leaves out/makes no mention of the fact that the KACR must be deactivated. It is the device on the other end of the Ex. cam, and you must pull the little spring off of it to deactivate it.
Why those idiots failed to mention this extremely important part of the MCM is beyond me.. Your KLX won't start when warm/hot until you manage to pull the spring off the KACR !
#968
I just did this modification on my 2018 EFI KLX 250. I did not touch the ACR at all and I have had no issues with that as of yet. It still starts the same as before with little to no effort. My bike is completely stock except for doing the clutch switch bypass and Marcelino's timing modification. The performance difference is noticeable.
#969
Maybe Kawasaki put the mechanism where it belonged. That was one of Marcelino's comments, it was out of position when stock.
From my experience and observation, the ACR is totally unnecessary. I have mine disabled and the bike starts virtually instantly, even at 3 degrees F. Neither Honda nor Yamaha bother with a CR on their 250s and some of the KLX650 riders disable or remove them from their 650s, I don't trust doing that, since the 650 really works hard even with the CR.
If I have the cams out again some time that ACR will be pressed out. Useless metal. It was left over from when the 250 was a kick start only off road bike - grew into the KLX300. There it may be needed, but not with the E-start.
From my experience and observation, the ACR is totally unnecessary. I have mine disabled and the bike starts virtually instantly, even at 3 degrees F. Neither Honda nor Yamaha bother with a CR on their 250s and some of the KLX650 riders disable or remove them from their 650s, I don't trust doing that, since the 650 really works hard even with the CR.
If I have the cams out again some time that ACR will be pressed out. Useless metal. It was left over from when the 250 was a kick start only off road bike - grew into the KLX300. There it may be needed, but not with the E-start.
#970
I just did this modification on my 2018 EFI KLX 250. I did not touch the ACR at all and I have had no issues with that as of yet. It still starts the same as before with little to no effort. My bike is completely stock except for doing the clutch switch bypass and Marcelino's timing modification. The performance difference is noticeable.
Diablo, I don't know if you got lucky or if '18's have a "forgiving" KACR indexing - but anyone doing this mod on an '18, who doesn't simply remove the KACR spring to deactivate it, needs to understand that they are engaging in an experiment - and be prepared (at least at this point in time) to re-disassemble the engine in order to pull off the spring if hot starting (starting while hot) becomes, or is, difficult to impossible..