Jump to content
Sign in to follow this  

Fuel economy Mikuni TM34

Recommended Posts

I looked around for quiet some while but couldn't find any posts about the mileage you would get with a Mikuni TM34 on XR250.

If someone uses this carb would be nice to hear something from you.

 

At the moment I only get half the mileage compared to stock carb. This is very critical on long rides, don't want to run out of gas and don't want to put on a bigger tank.

 

Normally I would get 150-160 km until I hit reserve which is probably another 20km so the range would be between 170-180km, which is very good.

 

With the Mikuni I only get 80km until I hit reserve the reserve is now less then half and I will get maybe 7-8 km that totals to 87-88km, that's very poor.

 

Hope someone runs a similar set up to compare things. My XR250L is all stock, with Gordon Mods, gearing is 13T/53T. I am a heavy guy with 130kg.

 

 

Share this post


Link to post
Share on other sites

We use the flat slide 34mm.On two gallons we get from 50-75 miles.On our 300cc,when they where 250s much less.We are jetted for power not Mpgs.There is many mods you can do to the 34 carb.Most are not jetted right.Also when you bolt on carb on stock motor,you need airbox mods,header,muffler mods.want a bigger carb,want more flow.You need to to get more air in and out to make it work.BTR

Share this post


Link to post
Share on other sites

We use the flat slide 34mm.On two gallons we get from 50-75 miles.On our 300cc,when they where 250s much less.We are jetted for power not Mpgs.There is many mods you can do to the 34 carb.Most are not jetted right.Also when you bolt on carb on stock motor,you need airbox mods,header,muffler mods.want a bigger carb,want more flow.You need to to get more air in and out to make it work.BTR

So if my calculation is right, then it's about the same then my Mikuni, a little more or less, at least I have some value now, thanks a lot. As I do a lot of long distance single treks I will  put the stock carb on then, give me a longer range, which is very critical here in Thailand in the middle of nowhere, bigger tank is not what I want.

 

Another member came up with this calculation:  (10 KPL = 23.5 MPG my fuel economy) thanks MarxMyth for that.

Share this post


Link to post
Share on other sites

My stock 250L gets 60mpg on dual-sport trips with a 4.2 gallon tank.  I only fill it when I'm riding long distance.  For local stuff, I put in two gallons.

  • Like 1

Share this post


Link to post
Share on other sites

Is this with the Mikuni TM34?, that would be not bad then.

 

No, it's stock which means no modifications except fine tuning the jetting on the original carb and opening the breathing slightly.  

Share this post


Link to post
Share on other sites

I have the aloop tank on mine,so holds less gas then stock.Single track in Baja same,no gas,nobody.I just carry 1 gal more,if I need go more then 50/70 miles.Since its my day bike works good for me.On my xr440 or Wr450 (4 gal xr-wr tank 3.6) sometimes I need carry two more gal,on my belt.Pain to do so,but more pain to walk out.

Share this post


Link to post
Share on other sites

I have the aloop tank on mine,so holds less gas then stock.Single track in Baja same,no gas,nobody.I just carry 1 gal more,if I need go more then 50/70 miles.Since its my day bike works good for me.On my xr440 or Wr450 (4 gal xr-wr tank 3.6) sometimes I need carry two more gal,on my belt.Pain to do so,but more pain to walk out.

Thanks for all the input I am alittle disapointed about the fact that the mikuni uses so much gas, most seller say in the discription, that this carb has better atomization of fuel and for this will use less gas then stock, this is just not true, or blame it on my incompetence. I can see the improvement, this carb is great but not greater then my modified stock, which is not even the PD carb, just a vacuum pump carb from the VE-series from Keihin. I will keep that carb, for another XR250 project, that will be race only, but for long distance I will stay with stock for sure

Share this post


Link to post
Share on other sites

Hello,

 

New to forum. Living in Cambodia would like to buy a xr250, I hav been riding a Yamaha dt125 for the past four years. I need somethin bigger for the SR to PP trips, I think the XR my be what I need.

 

I am very familiar with mikuni carbs and would like to convert the stock to a mikuni. Is the TM34 the best conversion available? Is this carb and a good selection of jets available in Thailand? In Cambodia especially Siem Reap I have not found anything, that would support this.

 

Thanks for the help.

Share this post


Link to post
Share on other sites

Wow...  that fuel milege sucks!  My bike is stock (with Gordon mods) and goes 100 miles before I have to think about hitting reserve.  Note to self...  do not cut the fuel miles IN HALF by installing one of those carbs!  With jetting, I have the stock carb working pretty good, so that pumper would have to make it run like the 400 in order to make me want to change!  No Thanks!

 

Good Luck!

Share this post


Link to post
Share on other sites

The 34mm is a flat slide carb    is,not pumper carb.My stock motor got less MPG then my xr300 motor.If your getting 100 miles from stock tank your doing good. With the stock motor I would run it wide open all day.No power at low revs.Big bore motor ride it at low rpms as it makes big power like a 440.BTR    Forgot riding the 300 easy,I have got 80 miles out of it. Pushing it hard in,deep sand,up hill as little as 60 miles on 2 gal.

Share this post


Link to post
Share on other sites

The 34mm is a flat slide carb    is,not pumper carb.My stock motor got less MPG then my xr300 motor.If your getting 100 miles from stock tank your doing good. With the stock motor I would run it wide open all day.No power at low revs.Big bore motor ride it at low rpms as it makes big power like a 440.BTR    Forgot riding the 300 easy,I have got 80 miles out of it. Pushing it hard in,deep sand,up hill as little as 60 miles on 2 gal.

 

Pushing it WFO...  especially in deep sand...  Nothing is going to get good fuel mileage there!  I don't generally run mine WFO, as you can't around here in hilly, woody terrain...  except on the occasional hill climb or short stretch.  Not much in the way of wide open spaces around here!  I don't need that much power where I ride, so I'm generally in a gear higher than what most would run, and use smoothness...  except where I need to loft the front wheel over a log/rut or something. 

Share this post


Link to post
Share on other sites

Hello,

 

New to forum. Living in Cambodia would like to buy a xr250, I hav been riding a Yamaha dt125 for the past four years. I need somethin bigger for the SR to PP trips, I think the XR my be what I need.

 

I am very familiar with mikuni carbs and would like to convert the stock to a mikuni. Is the TM34 the best conversion available? Is this carb and a good selection of jets available in Thailand? In Cambodia especially Siem Reap I have not found anything, that would support this.

 

Thanks for the help.

The XR250 are bulletproof machines I swear by them I have ridden them in Thailand for more then two decades. For the carb question I can tell you this:

 

a) Mikuni is adding some punch to the XR250, it feels like you have a bigger engine

 

B) the fuel economy is not very great, I only get half the mileage that I used to with the stock carb.

 

c) depending on which XR model you get in Cambodia, you might have either the PD carb, which is great or the VE carb, which is o.k but harder to tune

 

d) it is not a problem to get jets for Keihin Carbs here in Thailand, you find plenty of them around the scooter shops, as for the mikuni it is almost impossible to get the jets from 

    here

 

e) if you don't mind fuel economy and do a lot of racing get the mikuni, if you want to do long distance riding you're better off with stock and a different gearing

 

   (for example: I run 13T front and 53T rear, this is killer for uphills, nothing is too steep and I weigh 130kg, which is quiet a lot, but you'll suffer high speed, I still can crank it up to    

   100kph but if doesn't feel good and I hear the engine screaming)

 

I hope this helps you to understand, I was hunting on ebay for different carbs and they are all great but, now I think the stock carb is still the best choice for a non performance rider

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×