Kick-backs for dicussion...

[Paul]

It doesn't bother me, I just can't imagine why that bike is doing that if everythings good.

[John]

Well I think there are more out there who is experiencing the same problem. Could it be that this problem becomes more obvious when you ride the bike on tarmac (blacktop for you guys in the US)? I mean all of us so far are motarders.

/John

[John]

Solved!

Having discussed this problem with a serously good mechanic he helped me to draw to correct solution - which I have verified. It's so simple when you think of it.

Problem; throttle not open but the engine still delivers power. It sucks air + fuel even though the throttle is closed = worn throttle! That's what you get for buying an old machine...

Bought a better second hand carburetor and the problem is gone. The new carb is Keihin PJ not the PWK which is the original for KX5. This carb is more biased towards off-road not MX. A bit too slippery outside today to verify all aspects of the mod but it seems to be OK.

The PJ throttle is oval not flat. And there are different models / sizes of throttles for different setups / bikes. I am not sure I can ever get this carb to work well with my bike unless I buy all sorts of throttles and needles and keep on testing. This will probably cost me more than a brand new PWK carb...

I will keep on looking for a newer PWK carb and see if that solves the problem.

/John

[doordie]

Hello everyone!
You talk about kickbacks and i have had them to,only solution is a new carburator or fix the old one with new aluminum in the slide.Someone talk about buy a new carb... but i have somes friends here in Sweden who prefer LECTRON-carbs.. 38mm-48mm. They were very easy to "fix" to right jetting `cause only a a needlejet and a powerjet.They are is easy to reech to.We have a company here in Sweden who sells them(EBOS high performance), but they are from US,so it must be easy to get them for you,hehe.
Cost about 450-500$ (5000kr)here.I have not try one my self ,but i will....!

[John]

The mechanic - Bengt from http://www.deltamc.se yet another Swede told me that the newer PWK cabs has a crome throttle and is less likely to wear out. I will se if I can find one of those before I buy a new bike...

/John (Sweden rules!)

[kawdude]

Mine is a 94 and I have the same problem.  What I noticed is that it's worse now that I put on the carb spacer and flywheel wieght.  It makes me think that mine is related to a leak.  Nothing else changed...

[AZSingletracker]

Just a thought when you mention the cage and spacer. When you cut the intake boot down, did you nick the small factory "bead"seal on it? It would be a very easy place to develop a small intake leak. Even more so with V-Forces recommended "hack saw blade" method of cutting it down.

Personally, I didn't like the very little narrow factory seal on the boot and opted for an additional gasket at that point for a total of three gaskets at the reed spacer, cage and boot connection. Anyone else notice this same thing at the boot seal area?

[banshee_srb]

look like a leaking needle seat and too mush advence on timing!!!!take a look at the back plate if not loose by vibration or (hot point) in combustion chamber!!!! engine pingking?

sorry for my bad english!!!!

[kawdude]

When you cut the intake boot down

I didn't cut anything...what was I supposed to cut???  I did use the provided Moose gasket between the boot and the spacer and another between the spacer and the jug.

When I had it apart I went thru the carb.  I noticed that needle jet button still had spring but would not hold the floats up.  Is this normal.

[mikesmith]

I"m not sure if the springs still intact how it wont hold the float up?Is your float level set right?I found mine worked best set a little higher than listed in manual and cleared up a rich condition I couldn't get rid of with jetting.Does your carb overflow with the bike only leaned over slightly?If in doubt it's not a bad idea to replace the float needle and set your float level,try it on the high side of specifications.

[mikesmith]

Banshee srb,we may not all have the English language in common,but whats good is we all have fun riding in common.Thats whats important,so dont worry about your English,we can read your writing just fine.

[banshee_srb]

i had that problem the needle had a litle ridge and i was suspecting a leak from the float so i change both and i had a little to much advence on timing so i retard it i set the back plate in the midle just like they say in the manual shop and i solve the proble!!!!

[AZSingletracker]

I didn't cut anything...what was I supposed to cut???  I did use the provided Moose gasket between the boot and the spacer and another between the spacer and the jug.

When I first made the post, I didn't see the original post went to two pages.

The cutting of the boot was for the V-Force cage to fit, not for the install of the spacer. Sorry for the confusion.

[kawdude]

Oh ok!  I was scared for minute.!!!

[kawdude]

Running into the same problem on my kx.  Problem has gotten considerable worse after installing the moose reed spacer (gaskets?) and Steahly weight.  Any further suggestions.  Could float level cause this?