Author Topic: TM34SS float level  (Read 2787 times)

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monaro308

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TM34SS float level
« on: March 30, 2010, 02:22:52 pm »
Hi all,does anyone have the float level specs on the RM125F 1985 TM34 flatslide and where its measured from?
Sudco site shows TM34mm as 17-19mm but doesn't show if its taken from the base,less gasket or from the main jet boss base.

The bike fires up fine then runs fine,sounds crisp and then loads up big time (all this is at idle)and if i shut the tap it eventually clears up.
Needle and seat "appear" to be fine as there is no overflow through the tube.
If the carby is held upside down,needle "pops" off nicely with a pressure guage and does not bleed off.
I'm leaning towards float level at the moment

Also if anyone has a spare  '85 RM125F owners manual for sale...PM me  ;D
Cheers....Mario

Offline suzuki27

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Re: TM34SS float level
« Reply #1 on: March 30, 2010, 08:12:52 pm »
10.9mm plus or minus 1mm. Measured from base of main jet housing with main jet and jet ring removed.Cheers.

monaro308

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Re: TM34SS float level
« Reply #2 on: March 31, 2010, 01:13:41 am »
Thanks 27 i'll give that a go tomorrow...today ;D
Cheers...mario

RMJJ

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Re: TM34SS float level
« Reply #3 on: March 31, 2010, 08:18:15 pm »
They do load up and need a good rev to clear out if all it's doing is sitting there at idle

monaro308

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Re: TM34SS float level
« Reply #4 on: April 01, 2010, 01:20:40 am »
I had a play with the float level today and no luck.
RMJJ it idles from a choke start,i take the choke off and it idles fine and then loads up and dies.
Drain the bowl and do the same again and fires up straight away.If i hold the throttle about 1/4 to 1/2,its fine then starts 4 stroking,turn the tap off,it still 4 strokes then clears up to nice crisp revs until its out of fuel.
Turn the tap on,fires first kick.
I pulled the airbox off to see whats happening and as soon as it loads up,it is spitting fuel out of the inlet side of the carby.Tap off,clears up and great again.

I used my pressure guage on the inlet and it doesn't even hold pressure.I turn the carby upside down and pressurize it and it holds 6-9psi no problems.
I tried 2 other needle and seats (second hand) and they all did the same thing.

Another thing that i "think" may not be helping is the angle of my carby.It points down at the front because of the conversion.
Maybe the angle of the carby is effecting the pressure of the arm on the needle and causing not enough seating pressure.....(maybe??)

I'll try it again today with the front on a block to get the carby level and see if that makes any difference.
Its a strange problem,otherwise the bike sounds nice and crisp and i can't wait to take it for spin.
I'll check on the price for a new needle and seat....but i'll sus out the carby angle first and go from there.



Offline tony27

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Re: TM34SS float level
« Reply #5 on: April 01, 2010, 05:37:08 am »
How is the overflow in the float bowl-is it a vertical type or the angled type. One of the guys on trials central was having problems with his keihin pwk overflowing which was caused by the overflow fouling the float. Clutching at straws here

Offline bazza

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Re: TM34SS float level
« Reply #6 on: April 01, 2010, 06:44:51 am »
try needle jet and seat
Once you go black  you will never go back - allblacks
Maico - B44 -1976 CR250- 66 Mustang YZF450,RM250
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monaro308

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Re: TM34SS float level
« Reply #7 on: April 01, 2010, 09:03:00 am »
Hi tony the overflow tube in the bowl is a vertical type that slides into the main body to outlets on either side of the carby and clear of the floats.
Bazza....needle jet or needle and seat?
I forgot to mention that the fuel is not overflowing out of the tubes...ie like a buggered needle and seat or high level.
I also thought about the 2 floats being on posts if they were binding,but i poured fuel in the bowl and up they came.
I'll try the bowl on the same angle and see if the floats bind.

back to it!

Rechecked Tony...the o/flow tube is angled the other tube must be breather
« Last Edit: April 01, 2010, 10:29:38 am by monaro308 »

monaro308

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Re: TM34SS float level
« Reply #8 on: April 01, 2010, 02:17:13 pm »
Ok i tried everything over again and no luck.
I then tried the VM32 from my RM125T and it was fine,so i've ordered a needle and seat kit and will go from there....till next week!  ;D

Offline Freakshow

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Re: TM34SS float level
« Reply #9 on: April 01, 2010, 02:26:02 pm »
are the floats in and up the right way round ?
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Offline tony27

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Re: TM34SS float level
« Reply #10 on: April 01, 2010, 05:15:42 pm »
On the keihin the tube for the overflow angles up at 45deg from the base of the bowl, it can be a pain to fit things back together due to lack of space. If slightly bent it rubs on a float to the point of holding the float down enough to stop it sealing

monaro308

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Re: TM34SS float level
« Reply #11 on: April 02, 2010, 01:15:49 am »
Yep freakshow,they are even marked "up" on the floats so i can't go wrong there ;D
I also checked for any fouling of the floats....all good there.
I always thought if the needle and seat was knackered,you would have issues with over flowing fuel out of the bowl...this doesn't.
Would changing the pilot jet cause a major tune change like what i have?
I started with a 25 (PE size)then went to a 30 and i tried a 35 very quickly before i went to work and that seemed to load the engine up very quickly.
I'll go back to the 25 and try that again to eliminate my previous steps.

Stay tuned....untuned in my case ::)

monaro308

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Re: TM34SS float level
« Reply #12 on: April 06, 2010, 05:12:28 pm »
Well after countless hours of head scratching and swearing and smelling like a 2stroke engine for the last few days....I found the problem.....the bloody slide needle/jet needle was the wrong one and length by about 5mm+
The needle was so high up at idle in the needle jet and main jet,it was pulling fuel straight out of the bowl through the main.
I can't imagine what the last bloke was going through with the wrong needle...and i thought i'd checked it when i swapped to PE jetting on the main and pilot.
I think the needle and needle jet,i have to buy through Suzuki.
Does anyone know how to x reference the PE needle jet and jet needle to the RM numbers?
PE  needle 60P17-3   needle jet R-3
RM needle  6FP55-3  needle jet R-0

What a relief ::)