Please Help. Problems with Mikuni TM40-6 on Honda XR650R

View previous topic View next topic Go down

Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  antcap on Thu Apr 15, 2010 6:42 am

I have problems with Mikuni TM40-6. I have bought new the complete set modernised for XR650R. I have established the carburettor on XR650R 2006 with standard an exhaust and the standard air filter. I cannot will get rid of shots in the muffler at return throttle even when the motorcycle does not move. I do not understand, why frequency of turns of the engine strongly depends on motorcycle position? If vertically turns 1200, in inclined position (on side stand) - 1600. The carburetor is now completed Pilot Jet 12.5, Pilot Air Jet 1.1, Main Jet 135.

Somebody can had experience on adjustment of this carburetor? Specify please the size Pilot Jet, Pilot Air Jet, Main Jet and position Jet Needle for the best work of the carburetor. Specify how much early it should switch on and off pump (position of screws of regulation). Define, this carburetor how much smoothly worked.
Thankful in advance for the help.
avatar
antcap
L Rider

Joined : 2010-04-15

Posts : 4
Location : Moscow (Russia)
XR650R Year : 2006

Back to top Go down

Re: Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  Hew on Thu Apr 15, 2010 10:27 pm

This is the set up that I am running which was posted somewhere by Borynack. I have found it to be absolutely spot on so far with standard exhaust and air box.

I didfind that I needed to adjust the float height. I initially set it to the correct height but found the bike was flooding everytime it went on the side stand and even going down steep hills.

One other item to check for is air leaks on the carb to engine rubber manifold.

Pilot air jet BS30/97-1.2

Pilot Jet VM28/486-25

Main Jet N100.604-140

Needle Jet 784-13002-Y4
avatar
Hew
XRR Freak

Joined : 2009-01-03

Posts : 269
Location : North Wales, UK
XR650R Year : 2005

Back to top Go down

Re: Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  antcap on Fri Apr 16, 2010 5:40 am

Thanks. Interestingly than the seller is guided completing Mikuni TM40-6 for Xr650R such small Jets which need to be changed at once??? With those Jets which you have specified you have no problem with shots in Muffler?


Pilot air jet BS30/97-1.2

Pilot Jet VM28/486-25

Main Jet N100.604-140

Needle Jet 784-13002-Y4[/quote]
avatar
antcap
L Rider

Joined : 2010-04-15

Posts : 4
Location : Moscow (Russia)
XR650R Year : 2006

Back to top Go down

Re: Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  Hew on Fri Apr 16, 2010 4:09 pm

Shots in the muffler

This could well be a sign of an air leak between the carb and the engine. I have read that this is a common problem when fitting the Tm40 carb
Check that all the rubber manifolds are fitted correctly and the clamps are nice and tight.
The air leak could also be between the cylinder head and the exhaust. Check there for leaks.

I am happy with my set up. It pulls well at low revs and rips when I open the throttle.

As I have said I needed to adjust the float height to prevent the carb from flooding.
Good luck
avatar
Hew
XRR Freak

Joined : 2009-01-03

Posts : 269
Location : North Wales, UK
XR650R Year : 2005

Back to top Go down

Re: Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  antcap on Sat Apr 17, 2010 6:45 pm

I have increased an aperture in Pilot Jet from 0.35 mm to 0.5 mm (I
hoped that having increased section 12,5 area in 2 times I will receive
Pilot Jet №25), and also in Pilot Air Jet from 1.08 till mm (Pilot Air
Jet 1.1 has increased, I hope, till the size 1.2). Shots in the muffler
practically were gone. Problems with change of turns are not present
more. The power became huge. Remained small дергания in the moment from 1/8 to 1/4 throttle. Now I am almost happy with this
carburettor.
Can be at you there is a possibility to measure diameter of the central
aperture at Pilot Jet 25 or 22,5 or 27.5 that I could change an
aperture in the Jet. Thanks. Anton.
avatar
antcap
L Rider

Joined : 2010-04-15

Posts : 4
Location : Moscow (Russia)
XR650R Year : 2006

Back to top Go down

Re: Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  Hew on Sat Apr 17, 2010 7:05 pm

antcap wrote:I have increased an aperture in Pilot Jet from 0.35 mm to 0.5 mm (I
hoped that having increased section 12,5 area in 2 times I will receive
Pilot Jet №25), and also in Pilot Air Jet from 1.08 till mm (Pilot Air
Jet 1.1 has increased, I hope, till the size 1.2). Shots in the muffler
practically were gone. Problems with change of turns are not present
more. The power became huge. Remained small дергания in the moment from 1/8 to 1/4 throttle. Now I am almost happy with this
carburettor.
Can be at you there is a possibility to measure diameter of the central
aperture at Pilot Jet 25 or 22,5 or 27.5 that I could change an
aperture in the Jet. Thanks. Anton.

I am sorry I don't understand the question. The pilot jet in my carb is 25 I bought it like this.
avatar
Hew
XRR Freak

Joined : 2009-01-03

Posts : 269
Location : North Wales, UK
XR650R Year : 2005

Back to top Go down

Re: Please Help. Problems with Mikuni TM40-6 on Honda XR650R

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum