lamhound

98 honda trx450s spark problem

7 posts in this topic

hi guy need help on this one my trx450 start good idle good when i rev it it 4000 i lose the spark and it miss and back fires what could be the problem run fine till up to 4000 rpm but will some time go to 5500 no problem :aargh:

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hi guy need help on this one my trx450 start good idle good when i rev it it 4000 i lose the spark and it miss and back fires what could be the problem run fine till up to 4000 rpm but will some time go to 5500 no problem :aargh:

Are you sure it's a spark problem and not a fuel flow problem at high rpm?

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I would start with the CDI and/or the pickup. Ajmboy has a good point too, what makes you think that it is losing spark? You may just need to clean the carb and/or adjust the floats or something.

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no its not the carb when i put my volt meter on the input side of the coil i can see the volt start at 40volt @ 1500rpm the 210volt @ 3900rpm then nothing till it droppers back into the 3000 rpm range then i got volt again or when i put my timing light on the same thing light flashes till 4000 rpm then noting like it would have a rpm limiter i got a friend coming over with the same Honda i will try swapping the cdi i will keep you posted

thanks

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i change out cdi from friends quad guess what runs very good will hit 7000 rpm now. phone Honda dealer wants $400.00 for new one but found a used one at a bike recyclers for 40.00 so got my finger crossed it works thank for the reply so on till next time

thank eh

mike

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Right on, good luck with the used CDI. If you have any problems with it, try Service Honda, they have OEM Honda parts for quite a bit less than what your dealer is probably asking.

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