6 replies [Last post]
PGilsdorf
PGilsdorf's picture
 Offline
VBMWMO #7535
Joined: 04/18/2009
Posts: 2

Hi everyone,
First time poster here. I'm having some trouble getting my R35 to run right. After many attempts at kick starting it will eventually start and run, albeit roughly, for a while until it dies after a minute or so. Everytime it gets harder and harder to start.

Other info:
-I have to keep the spark adjustment lever all the way aft or it dies.
-Also having issues with the carb leaking.

I took apart the carb. As you can see in the pics the float has been soldered on. What are the 4 notches for? which notch should it be on? I have a feeling the float could have a hole in it, if so would that be causing my issues?

I have yet to check the timing on the magneto.

Also another simple question... My throttle is binding at the handlebar and only opening half way, how do I remove the levers to disassemble the throttle grip?

Thanks!




mdunn
mdunn's picture
 Offline
VBMWMO #9044
Riverside, CA
Joined: 02/21/2008
Posts: 87
Re: R35 hard starting and other issues

Hello,

Ok, first thing first. Put some new NGK plugs in it. I feel they are the best bet for any German bike, yes BOSCH are not that great. Ok, next make sure your points are set on the right gap. Make sure your bike is timed right, this is possible its not timed right and this bike has a actual chain and if its off one or two teeth it can make a difference. Also for the hell of it check the valve clearence (WHEN COLD).
Your bike does not have a magneto, thats a generator. You have one timing chain under the front cover.
The controll wires are simple. Undo it from which area you need to address( Carb, front brake,clutch). Next remove the pin that holds the clutch or brake lever. Now the actualbar end that is set into the handelbars can be set in by force or sometimes a set pin, roll back the grip and check this. If no set pin you can pull that bar end off and than pull the grip and wire off.

On this particualr carb it has only one gasket on it where the jets are, you have 3 jets on it. I am not sure on the numbers but its in sequence smallest to biggest and there is numbers written on each jet, make sure its right. They go something like 45 60 65 or something like that, i am not home to check the actual numbers. Now the float works like this, when you turn the gas on it fills the bowl up with gas and the float rises, if your float doesnt rise when you pour some gas in there right now and you are looking at it, PROBLEM sloved ( hole in the float). If it does rise than read on. The little pin that has the settings on it with lines will allow the float to sit lower or higher in the bowl. If that bowl rises and the top of the pin doesnt seat with the top of the float bowl cap it will continue to leak because its not shutting off and running and running thus gas pouring out of the carb. Usually if this is leaking like crazy , this is the problem and the pin is not fully seating right on the top of the float bowl cap.
In this forum and even on the Krad riders forun their are alot of R35 owners. You will find help.

"PGilsdorf" wrote:

Hi everyone,
First time poster here. I'm having some trouble getting my R35 to run right. After many attempts at kick starting it will eventually start and run, albeit roughly, for a while until it dies after a minute or so. Everytime it gets harder and harder to start.

Other info:
-I have to keep the spark adjustment lever all the way aft or it dies.
-Also having issues with the carb leaking.

I took apart the carb. As you can see in the pics the float has been soldered on. What are the 4 notches for? which notch should it be on? I have a feeling the float could have a hole in it, if so would that be causing my issues?

I have yet to check the timing on the magneto.

Also another simple question... My throttle is binding at the handlebar and only opening half way, how do I remove the levers to disassemble the throttle grip?

Thanks!




__________________
Bruce Frey
Bruce Frey's picture
 Offline
VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
R35 hard starting and other issues

Regardless of whether the float leaks (which will make matters worse), with all that solder, it is probably at least 3 or 4 grams too heavy and would cause idle problems. I think you want a new float and needle.

I have never seen a float needle, even a bottom feed, with different notches. It seems that the notches are way too far apart to be of any use in adjustment. The correct fuel level in a float bowl is a matter of a very few millimeters. Generally, notches are used in main jet needles.

Mike, are you SURE the float needle should have notches? It sure looks like the top of a main jet needle. (I do not have an R35 Ersatzteilliste to check)

Bruce

mdunn
mdunn's picture
 Offline
VBMWMO #9044
Riverside, CA
Joined: 02/21/2008
Posts: 87
R35 hard starting and other issues

Bruce,

Actually it shouldnt have notches at all and the float would be stuck into position ( on a real SUM). If he just replaced the float with the correct needle and float itself might slove all of his problems, your right Bruce. The heavier that float gets the more its not going to ever seat in the top cover and stop the flow of gas. You are also right this needle would be used for a actul main jet or( Slide of a carb)

Mike

"Bruce Frey" wrote:

Regardless of whether the float leaks (which will make matters worse), with all that solder, it is probably at least 3 or 4 grams too heavy and would cause idle problems. I think you want a new float and needle.

I have never seen a float needle, even a bottom feed, with different notches. It seems that the notches are way too far apart to be of any use in adjustment. The correct fuel level in a float bowl is a matter of a very few millimeters. Generally, notches are used in main jet needles.

Mike, are you SURE the float needle should have notches? It sure looks like the top of a main jet needle. (I do not have an R35 Ersatzteilliste to check)

Bruce

__________________
PGilsdorf
PGilsdorf's picture
 Offline
VBMWMO #7535
Joined: 04/18/2009
Posts: 2
R35 hard starting and other issues

Bruce and Mike, thanks for all the help. What is the part number for the NGK plug?

I had a feeling the float was not original, the threads on the needle are too long. So long that you can lock the seat closed if you screw it in all the way.

Now the hard part, where can I find an original float and needle for the Sum 741 carb?
Thank you!
-Phil

Bruce Frey
Bruce Frey's picture
 Offline
VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
R35 hard starting and other issues

"PGilsdorf" wrote:

Now the hard part, where can I find an original float and needle for the Sum 741 carb?
Thank you!
-Phil

I will post some possible sources in a day or two.

Bruce

Bruce Frey
Bruce Frey's picture
 Offline
VBMWMO #6316
Texas Hill Country, USA
Joined: 10/27/2006
Posts: 574
R35 hard starting and other issues

Sorry for the delay, but I am catching up (too much work) after taking a day off to go to Veterama.

I would try:
Vech - Benchmark Works http://www.benchmarkworks.com/

Mark Huggett - http://www.bmwbike.com/

Oldtime Garage - http://www.oldtimergarage.szn.pl/menu_ang.html

E. Breindl Grope - http://www.omega-oldtimer.de/

Faak - Tillmans - http://www.faak-tillmanns.com/Produkte.46.0.htm

Philip Dreher - http://dreher-oldtimerteile.de/cms/index.php

Eckard Sieg - http://www.sieg-vergaser.de/

Vech (Craig Vechorik) is in the USA. The others are abroad, but you should be able to correspond with all of them in English. Payment from the USA will be easier with the first 3. If they do not show them in their catalogs, it is worth it to e-mail or call.

If they do not work, I have one more source that does not have a website.

You might consider replacing othr carb parts as long as you are ordering.

Bruce

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.