mk3 problem
mk3 problem
Hello. I have a crm mk3 motard. 160 jet 14-42 with fmf gold series. At 1st-2nd-3rd gear it goes really fast and good but at 4th-5th-6th slows down a little bit and stumbles. A friend has mk3 motard with 150 jet fmf gold series and goes really good at all gears. I tried his jet but then mine goes worst.Mine reach top speed at 700m and my friends with the same driver at 300m!What's the problem??
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knackeredMk1
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Re: mk3 problem
Could be a variety of reasons:
1) The gearing is different. Are you sure that the gearing is the same
2) The powervalve is not opening fully.
3) You are loosing a lot of power because your gearbox and/or chain/sprockets are worn.
4) Your jetting is wrong.
5) Your airfilter is dirty.
6) There seems to be a gear selection monitor on the Mk3 maybe this is faulty .
7) Maybe your engine is worn/not tuned as much as your friend's.
8) Your silencer needs repacking. Do you both have the same silencer .
9) You have an air leak on the intake side. Standard jetting for the Mk3 is 150 main jet. Usually, but not always, FMF exhausts require leaning the jetting not richening
Could be a bit of any of these and more .
1) The gearing is different. Are you sure that the gearing is the same
2) The powervalve is not opening fully.
3) You are loosing a lot of power because your gearbox and/or chain/sprockets are worn.
4) Your jetting is wrong.
5) Your airfilter is dirty.
6) There seems to be a gear selection monitor on the Mk3 maybe this is faulty
.7) Maybe your engine is worn/not tuned as much as your friend's.
8) Your silencer needs repacking. Do you both have the same silencer
.9) You have an air leak on the intake side. Standard jetting for the Mk3 is 150 main jet. Usually, but not always, FMF exhausts require leaning the jetting not richening
Could be a bit of any of these and more
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eddie666
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Re: mk3 problem
have you a free flow air filter or holes in the air box or a air leak to the carb,
we had lads that put k&n style air filters on there bikes then they would strugle with high reves under load ( higher gears )
the bike was getting to much air and making them run weak,
we used to use tape to wrap around the filters ( cone filters ) to bolck it off abit at a time untill it was sucking in just the right amount of air to run well,
not saying this is your prblem, look for air leaks to the carb, if nothing looks wrong try this : wrap a cloth a bit over the filter a bit at a time, and see if it helps,
to much it will smoke and pull back on you,
we had lads that put k&n style air filters on there bikes then they would strugle with high reves under load ( higher gears )
the bike was getting to much air and making them run weak,
we used to use tape to wrap around the filters ( cone filters ) to bolck it off abit at a time untill it was sucking in just the right amount of air to run well,
not saying this is your prblem, look for air leaks to the carb, if nothing looks wrong try this : wrap a cloth a bit over the filter a bit at a time, and see if it helps,
to much it will smoke and pull back on you,
Re: mk3 problem
1) What do u mean??A different gearbox??
2) We've checked this :)
3) Chain and sprockets are ok!How can i check gearbox??
4)I've tried 150 jet but then it goes worst :/ i'll try 158.
5)New and clean! :)
6)How can i check this..?
7)We've checked it and seems ok.
8)I have fmf power core 2 and my friend fmf but an older one i dont know which one.
9)I have a new intake.
2) We've checked this :)
3) Chain and sprockets are ok!How can i check gearbox??
4)I've tried 150 jet but then it goes worst :/ i'll try 158.
5)New and clean! :)
6)How can i check this..?
7)We've checked it and seems ok.
8)I have fmf power core 2 and my friend fmf but an older one i dont know which one.
9)I have a new intake.
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eddie666
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Re: mk3 problem
has it just had a engine rebuild? not run in yet!!!!
have you just put new parts on , exhaust / jets ect
if your piston rings are old / worn and you put uprated parts on this could affect the power,
have you just put new parts on , exhaust / jets ect
if your piston rings are old / worn and you put uprated parts on this could affect the power,
Re: mk3 problem
Hmm nope :/... piston is at very good condition...I have never "opened" the hole engine only cylinder to check piston cylinder conrod and cranksaft and they are ok.Reed and intake also ok.I have cleaned the jet and i ordered a new one 158 and waiting to arive to try it.
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eddie666
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Re: mk3 problem
what persition is your needle in? 3 down ect
if you move the clip down ( rasing the needle ) you will get more fuel in , clip up you get less fuel in,
its like up/down jetting,abit
cheak your oil pump settings ( full throtle line it up on pump )
what coulor is the plug end ? dark / brown / black = rich white = weak tan = right
dark / brown / black / wet to much fuel or oil
white / dry to little fuel or air filter letting to much in ( no filter / holes )
light tan / dry just right
light tan / wet to much oil
if you move the clip down ( rasing the needle ) you will get more fuel in , clip up you get less fuel in,
its like up/down jetting,abit
cheak your oil pump settings ( full throtle line it up on pump )
what coulor is the plug end ? dark / brown / black = rich white = weak tan = right
dark / brown / black / wet to much fuel or oil
white / dry to little fuel or air filter letting to much in ( no filter / holes )
light tan / dry just right
light tan / wet to much oil
Re: mk3 problem
I had jet 145 and it was white so i changed...Now i have 160 with the needle up cause at middle stumbles and cant work at all...I wait 158 to arrive and i will try mixing at tank to check if oil pump works well.
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eddie666
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Re: mk3 problem
it sounds like you have a air leak, could be a pipe off the carb or the top lose, cheak the intakes at the the back of the carb ( where the rubber goes to the air box ) if they are coverd by a bent housing seating or if silicon has been used to seal it on,
jeting is usaly 5-10 from standard sizing,
drain the bottom of the carb off , there may be water droplets in there from condonsation,
have you striped the carb down ( taken out the main jet atomizer housing and cleened out the holes )
are the float hights right and seated right,
to me its sounds like a air leak or a carb blockage ,
is the carb sitting vertical ( some times they start to tilt or people put them on wrong )
how long have you had it
did it run fine before any mods
look for bent fuel / traped / soft pipes that could stop the flow of fuel,
i had it on a bike the fuel pipe was soft and bent kinked .
look at tank breather fuel filter fuel lines carb rubber seals .
jeting is usaly 5-10 from standard sizing,
drain the bottom of the carb off , there may be water droplets in there from condonsation,
have you striped the carb down ( taken out the main jet atomizer housing and cleened out the holes )
are the float hights right and seated right,
to me its sounds like a air leak or a carb blockage ,
is the carb sitting vertical ( some times they start to tilt or people put them on wrong )
how long have you had it
did it run fine before any mods
look for bent fuel / traped / soft pipes that could stop the flow of fuel,
i had it on a bike the fuel pipe was soft and bent kinked .
look at tank breather fuel filter fuel lines carb rubber seals .
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knackeredMk1
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Re: mk3 problem
All good things to check above.
It does seem like a jetting problem to me as well. Though it is very difficult to diagnose from a list of symptoms. Try returnng the needle to the stock position (middle) so you have some kind of reference to work from.
It does seem like a jetting problem to me as well. Though it is very difficult to diagnose from a list of symptoms. Try returnng the needle to the stock position (middle) so you have some kind of reference to work from.
Re: mk3 problem
no only the jet i clean..thanks for all.. i will try and i will post again to say..
Re: mk3 problem
I have good news! :D I tried my friend's carb and exhaust and now mine reach top speed at 350m and stumbles only at 5th or 6th gear a little bit... Should i change to lower or higher jet...??
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knackeredMk1
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Re: mk3 problem
Strongly suggest you give your carb a good service and check if your exhaust needs repacking.
Re: mk3 problem
this is what i do.. the exhaust has 4-5 holes very small... i will clean the carb.. now with 150 main jet i put out the filter and it is gone better.. i think that the main jet needs more than 150..
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eddie666
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Re: mk3 problem
[quote="akis_d"]this is what i do.. the exhaust has 4-5 holes very small... i will clean the carb.. now with 150 main jet i put out the filter and it is gone better.. i think that the main jet needs more than 150..[/quote]
if you take out the air filter it will run weaker ( les fuel )
clean out the carb , all the air ways and jet holes , set it to standard settings and jet sizes,
put in a clean air filter, put in a new plug ( the right type )
set up the oil / throttle ,
see what happens then , if it runs well , leave it alone, if it still loses power it could needs rings or a reboure, or if you have a after market exhaust on it ( that will change things ) it could be your power valve sticking !
if you take out the air filter it will run weaker ( les fuel )
clean out the carb , all the air ways and jet holes , set it to standard settings and jet sizes,
put in a clean air filter, put in a new plug ( the right type )
set up the oil / throttle ,
see what happens then , if it runs well , leave it alone, if it still loses power it could needs rings or a reboure, or if you have a after market exhaust on it ( that will change things ) it could be your power valve sticking !