Kawasaki Motorcycle Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
I have a late 70s Kawasaki KV 75.
It had a dirty carbureter and the float had a pin hole in it. I cleaned the carburetor and installed a new float and needle and seat. I adjusted the float height as per my instructions. Roughly 21 mm measuring without the bowl gasket in place. I even checked the fuel height which is around 5 mm below the gasket surface. Fresh fuel mixed at 40:1. Oil injection not hooked up. New spark plug and air filter in place during testing.
My issue is.... it starts right up but bogs out. I have had the carb off more times then I want to mention and always the same. Starts but won't take throtle without bogging. If I turn the fuel valve off and let it start to run out of fuel..... it will then Rev out. So to me that says I am getting way to much fuel ???? I am very mechanically inclined but this bike is makin me feel pretty stupid. LOl. Any help you can give me would be greatly appreciated .
41406
 

·
Registered
Joined
·
138 Posts
Ok, assuming that the you cleaned all jets in the carb and made sure all passage ways are clear, here are a few things off the top of my head:
1) Check to make sure the carb slide was not installed backwards. The big notch in the slide must face the air filter. I have seen these installed backwards with resulting symptoms similar to what you described.
2)Make sure the pilot air screw is at the correct setting, which is probably 1.5 turns out from lightly seated but check your manual for this info.
3) Did you block off the oil injection port and are you sure it is not leaking air?

When was the last time it ran properly?
 

·
Registered
Joined
·
7 Posts
Discussion Starter #4
I have had the carb off so many times and thoroughly cleaned it. Checked the slide. Mixture screw set. Oil injection is disconnected. Ran this summer. Then sat. Found a hole in the float and was causing it to sink. Installed a new needle and seat and float assey. Hasent run right since then. I set the float height to factory spec. Tryed playing with the heights. Clip position on the needle and still bogging out. Grrrrrr.
 

·
Registered
Joined
·
138 Posts
Have you tried running it without the pod? While the pod is off can you take a picture looking straight into the bore of the carb and post here? Are the new carb parts OEM or third party?
 

·
Registered
Joined
·
7 Posts
Discussion Starter #6
I have tryed it without the air filter. No better. The parts aren't OEM. Some vintage Kawasaki parts company. So aftermarket. Will ad a pic of tge carburetor from the back.
 

Attachments

·
Registered
Joined
·
138 Posts
Ok. Having re-read everything it seems that your first hunch was probably correct; It is getting too much fuel.
After bogging it for a while, pull the spark plug to see if it is wet. If you still have the original carb parts, I would do a very careful comparison to make sure the dimensions of the float and float needle and seat are all identical. There are some badly produced copies out there and this could be the source of your problems.

Also are you 100% sure your float height specs are correct? Can you install the old float just to check its measurement? My thinking here is that may shed some light on what is going on. Since this carb was never meant to flow a gas/oil mix, it is possible that the previous owner made some changes to the carb to get it to run better with pre-mix instead of oil injection.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #8
I went back to the original needle and seat. Same issue. The float height specs seem to vary from what I can find . Do you know the "Proper " setting ? I never compared the floats that closely. I will though. As far as getting the height spec from the old float.... Won't be accurate as it's been played with also. Thanks for the reply.
 

·
Registered
Joined
·
138 Posts
The OE setup was as follows:
Mikuni VM15SC carb
Main jet 70R
Pilot jet 15
Needle 3G9 with clip in third groove from the top. The number "9" can vary so don't worry about that.
Air screw setting 1.5 turns out from lightly seated
Fuel level 4-6 mm
Please compare the floats very carefully and make sure the new float can move freely and does not hang up by hitting some other part of the carb. How are you checking the fuel level?
 

·
Registered
Joined
·
7 Posts
Discussion Starter #11
I was checking fuel level by float height in MM and I also checked it with a hose to measure the fuel height. All was within the specs I had found. I don't have the numbers with me right now. The engine number is
M T E
5 6 1 4 2
Thanks
 

·
Registered
Joined
·
138 Posts
The most accurate method is by fuel level as opposed to float height particularly where you are using an aftermarket float. See below.
41417
 

·
Registered
Joined
·
4 Posts
I have a late 70s Kawasaki KV 75.
It had a dirty carbureter and the float had a pin hole in it. I cleaned the carburetor and installed a new float and needle and seat. I adjusted the float height as per my instructions. Roughly 21 mm measuring without the bowl gasket in place. I even checked the fuel height which is around 5 mm below the gasket surface. Fresh fuel mixed at 40:1. Oil injection not hooked up. New spark plug and air filter in place during testing.
My issue is.... it starts right up but bogs out. I have had the carb off more times then I want to mention and always the same. Starts but won't take throtle without bogging. If I turn the fuel valve off and let it start to run out of fuel..... it will then Rev out. So to me that says I am getting way to much fuel ???? I am very mechanically inclined but this bike is makin me feel pretty stupid. LOl. Any help you can give me would be greatly appreciated . View attachment 41406
Anyone have some advice ?
Hey there is a gentleman on youtube kevin Bergeron that has helped tremendously with a kawasaki ke100. I know he has done some videos including the kv75, he is very thorough in explanations and his videos are very informative. In my experience if you post a question in thr comments of any video he responds within hours with just the right explanaion. Hope that helps good luck and ride on!!
 

·
Registered
Joined
·
7 Posts
Discussion Starter #14
Thanks for the info Gentleman. Never got back to the KV 75 yet. Will keep you posted when I do.
Thanks.
 
1 - 14 of 14 Posts
Top