Hey guys,

I'm not getting much range on a tank without the pump with a TM45 right now...I'm about to enable the pump...and wondering if it's going to get considerably worse??

Jeff

 

are your plugs fresh? and it might cost a little fuel.

 

Probably a little on the low end, thats when the pump squirts fuel directly into the air chamber. But, its not a huge stream.

 

Well, I know technically it should burn more fuel.

But has anyone noticed a difference in range/mileage?!?

My plugs are fairly new...does that matter?

 

fresh plugs with proper gap clean air filter, and proper jetting should help

 

I've been running the pump for several months now, several rides, and I don't fill my tank any more often than I used to without it. the additional fuel used is not enough to even notice. #50 nozzle mind you - the #60 and #70 nozzles have proven too rich, even at sea level the 60 is to much squirt.

FYI - before you enable the pump make certain the pilot is correct with the very same method outlined in the Mikuni tuning guide that came with the carb. it is very good instruction. I run 35 pilot at sea level. most guys not using the pump run a bigger pilot to help band-aid the bog, but this will cause you to be too rich once you activate the pumper. too big a pilot is a major source of bad fuel economy, with or without the pump.

* turn idle mixture in til she bogs, out til she bogs, set halfway between. then find out where she's at by screwing in til she bottoms, counting. if it was more than 2 turns out, pilot is too big. if less then 2 turns out, pilot too small. if you turned the mixture screw all the way out without ever getting a bog, the pilot is way too big. this method is fail safe and exact, and easiest way to correctly select the pilot jet. unfortunately for raptor guys they cannot perform this method due to carb location.
Just be certain to do this prior to trying to set up the pumper travel limits.

 

Hightower has good advice. Take it word for word.

 

Well obviously my pilot is too big then...Because I can turn out the air correction screw (same as idle mixture screw. right?) all I want without bogging...I tried it once and I screwed it out so much as it felt as if the screw was going to come out next turn...so I stopped and screwed back in to 2.5 turns out...where it sits today... I'm using a 40 pilot..which is what most people use on their 45...why would mine want a smaller pilot?..I thought maybe the lid being on is the reason..I dunno. I could take off the lid for the summer...but spring and fall is WAY too wet for running without the lid...


Jeff

 

All TM 45mm carbs do that Mr.Spinner! The won't bog when you turn it all the way out no matter what pilot you put in there. I put 27 pilot in mine once just to try it and it still did the same thing.

 

This may be the case on your carb due to strange circumstances or a potential problem that I know nothing of, but its not the case with mine. I dropped from a 40 to a 30 and immediately got the correct response to turning out the screw, and wound up having the screw 1-1/2 turns out. So I then installed the 35 pilot and reset the screw with the recommended method and the end result was a perfectly tuned pilot circuit exactly 2 turns out. I've used this method of tuning for many years, on many other carbs as well, and so have others on this forum also succeeded the same way with their TM45's. I'm not the only one that'll recommend it.
I also know that you had some bad luck trying to tune your pump and claim its not worth it, perhaps there is something wrong with the pilot circuit of your carb causing both these issues? Just trying to help, the pump rocks hardcore and I can't imagine life without it. All who have ridden my bike since its addition can attest to it.