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Discussion Starter #21 (Edited)
I finally received my thin wall socket in the mail. I was able to remove spark plug number 2. It also was really charcoal black on the electrode and a bit rusty.



  • I changed all three plugs for new ones.
  • The bike got a fresh battery.
  • I cleaned and oiled the k&n filter.
  • I replaced the foam in the aux box
  • I cleaned the carbs
  • the carbs received new genuine Keihin pilot jets (after I damaged the head during removal)
After assembling everything back on the bike: it starts immediately. Yes.
But after a small test drive, I noticed some problems:

1. There are coming exhaust fumes out of the piece of pipe underneath the engine, connecting the left and right headers. I hit that pipe when I was removing the bike from winter storage. (Don't ask)
I hope I will be able to fix this. Will look into this later. On this picture, you can see the black that came out after a few 100 meters test drive.



2. The motor starts good, but is not running good unfortunately. I don't believe, this is related to problem 1. Correct?
2a. Stationairy, it's very unstable. It's not running on 1 fixed rpm.
2b. Rotating the idle screw doesn't seem to have any effect. I don't hear any change in rpm.
2c. When I move the throttle a little bit, the engine wants to stall.


Probably something went wrong during reassembly. But what can it be??
(I left the air-fuel mixture screws and the synchronising screws untouched during dis/assembly)
 

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Will it only run with the choke on? That could indicate an air leak. Check the rubber diaphrams in the top of the carbs for holes or cracks by gently stretching them while looking for light to come through. Also, these carbs are sensitive to fuel level so double check the float adjustments. Let us know what you find. Good luck!
 

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Did you do a basic carburetor sync with the drill bit method?
 

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Discussion Starter #25
I did some checks:

  • doesn't run better with choke on
  • I checked the diafragma's before, during dis/assembly. They looked fine.
  • the carbs were synched last year. I didn't touch the screws now. Don't think this is the cause of the problem. (Don't know the drill bit method though. Will check it out later)
  • I did check the float level before. Not by connecting a tube, but by measuering the height. Was all the same for the 3 carbs.
  • I did a check by spraying deodorant near the inlet rubbers between the carbs and cilinders, to find an air leak. Didn't make any difference.




I am thinking about 2 possibilities now.

- I am always scared of over tightening the spark plugs on bikes and damaging the thread. So maybe I under tightened them? (Don't have a torque wrench)

- I have had a similar problem in the past with a moped. In the carb of that moped, normally some kind of clip was holding the needle in position. The clip was missing in the carb, so the needle could float/dance freely. The consequences were the same as my current issues. Maybe now something similar is the cause of the current problems??

Any other suggestions?
 

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Discussion Starter #26
I'm really starting to think it has something to do with bad installation of the needle.

How do parts 5, 6 and 2/3 connect to each other?
 

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Check the route of your gas cable carefully.
Is the choke cable properly adjusted.
What happens when you turne the idle adjustment screw.
I have 3 torque wrench but always tighten the spark plug by hand.
The original ones have none clip. ( original )
What position do the air / petrol screws have?
I think when I listen to the video something is wrong with your carburettor adjustment or assembly

PS.
What is the the drill bit method ????

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Discussion Starter #29
Thanks again for all the usefull pictures, Jan!
Now I am sure I have this wrongly assembled.
I had iT laid out on the table like that, but got confused because of the drawing in my Triumph service book.
I Will redo this later this week.
 

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Discussion Starter #32
Today I've put the needles in correct position. (Luckily I didn't need to remove the carbs from the bike)



But luck is not at my side... It's not running better. (Worse maybe?)


The new spark plugs after running a few times:



  • I tried tightening the plugs a bit more. No difference.
  • I checked the wiring of the coils. (Because I had to remove them, to reach the top of the carbs) Looks fine.
Getting a bit frustrated now... Beautiful weather the coming days... and no running bike... :)
Will work on the bike again, tomorrow.
Any suggestions?
Thanks.
 

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Discussion Starter #34
To be sure. All 3 pieces are not connected or clicked into each other in any way?
First put the needle into the piston.
Then put the needle cover on top.
Then put the spring on top.
Then fit the cover on top of the spring.
Correct?
 

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Advice 1 always remain calm there will probably be more nice weather.
Advice 2 take your time and take pictures next time during disassembly.
Advice 3 You tube enough videos how to properly clean a carburettor.

With your finger hold the needle up and then lay cover on top,let it down slowly, then put the spring on top.
CV stands for automatic gas slide control, your needle goes up through the membrane and spring.
Answer the following questions:
What position do the air / petrol screws have?
I suspect he's way too rich.
The carburettor is really clean ?? especially the stationary jets ??
Is the carburettor synchronized ??
The floats have the right height ??
All rubbers are in place ?? ( air / petrol screws )
petrol supply needles clean ??

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Discussion Starter #37
Advice 1 always remain calm there will probably be more nice weather.
Yes, off course, I know. If everything is always running smoothly, you don't learn anything. It is because of the mistakes you make, the problems you are dealing with, ... that you learn a lot.

Advice 2 take your time and take pictures next time during disassembly.
I already did. But I will definitely will make more in the future. You have a nice collection of pictures!

Advice 3 You tube enough videos how to properly clean a carburettor.
2 nights in a row now, I have been watching. :)
I also saw a video of an assembly/disassembly of a CVK36. Now I am sure that my needle placement is ok.

With your finger hold the needle up and then lay cover on top,let it down slowly, then put the spring on top.
Unfortunately this way is not possible with the carbs still in the bike. But I believe I did it correctly now. I did it twice too. Also checked that the diaphragma was fitted correctly.

What position do the air / petrol screws have? I suspect he's way too rich.
I do not know at the moment. I didn't touch them during dis/assembly. But I will definitely check this tomorrow. Is there a way of adjusting, without removing the carbs from the bike? I didn't try, but I can try with a ratchet wrench (with bit holder + bit), but then it is not easy to count the amount of rotations...

The carburettor is really clean ?? especially the stationary jets ??
Yes, it is clean. I cleaned the main jet (size 98) also with a steel wire. The pilot (stationairy) jets are brand new. I bought genuine Keihin (no aftermarket) pilot jets, size 38.(the old ones were pretty stuck, and the head was damaged during removal)

Is the carburettor synchronized ??
I did this last summer. Didn't touch the screws during dis/assembly. Don't have the tools right now to do a synchronisation again.

The floats have the right height ??
Luckily I wrote it down. All 3 measured 17.5mm.
The former owner of my Service Manual has also written 17.5mm in the book. I didn't do the test with the tubes.

All rubbers are in place ?? ( air / petrol screws )
Didn't move those screws during dis/assembly.

petrol supply needles clean ??
Yes, I think so. I thought all parts were pretty clean. Only in the float chamber there was some (strange) red powder.




Thanks for all the help!!!

 

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Discussion Starter #38
After looking into my pictures again, I see a difference how the throttle cable adjuster is set. Don't know if this does much harm?
 

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Are you sure the enrichening mechanisms are fully closed with the choke off?
Any sign of the bike running rich?
That red powder is the inner tank coating coming off... can clog an idle jet really easy.
 

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Your throttle cable adjustment is fine. I would suggest you turn the mixture screws in 1/2 turn (leaner) and try running the engine again. Do make sure the enrichening device (choke) is fully off once the engine has started and warmed enough to run without it.
 
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