Throttle cable problem?

[r3sc]

Hi Guys,

I have been working on a 72 GT750J and I have a problem which I can't explain.

The bike is fitted with a brand new genuine Suzuki throttle cable part number which I think was part number 58300-31000 but it could have been 58300-31001?

The problem is the cable appears to be too short and when fitted I am unable to get enough slack in it to allow the oil pump control arm to go all the way back towards the rear of the engine and when on full throttle the lines on the pump actuator arm and the pump body do not line up as the arm goes way past the required position where the two lines align. Also when on full throttle the three holes in the carb slides go way past the top edges of the carb inspection holes when the plugs are removed.

Also, the cable has just one curved fitting on it to go to the carb tops. Which carb is this curved fitting for?

What am I missing? Is the Haynes manual incorrect in its set up procedures? Is the cable wrong? Please help if you can and suggestions would be welcome.

Regards.

Pete.

[barney01]

Hi I have a 550 J the elbow goes to the right carb as you sit on the bike here you go

[canaletto5]

Hi Guys,

I have been working on a 72 GT750J and I have a problem which I can't explain.

The bike is fitted with a brand new genuine Suzuki throttle cable part number which I think was part number 58300-31000 but it could have been 58300-31001?

The problem is the cable appears to be too short and when fitted I am unable to get enough slack in it to allow the oil pump control arm to go all the way back towards the rear of the engine and when on full throttle the lines on the pump actuator arm and the pump body do not line up as the arm goes way past the required position where the two lines align. Also when on full throttle the three holes in the carb slides go way past the top edges of the carb inspection holes when the plugs are removed.

Also, the cable has just one curved fitting on it to go to the carb tops. Which carb is this curved fitting for?

What am I missing? Is the Haynes manual incorrect in its set up procedures? Is the cable wrong? Please help if you can and suggestions would be welcome.

Regards.

Pete.

Have a look at this page on Robinson's Foundry site

https://www.robinsonsfoundry.co.uk/shop ... handlebars

As Barney says, the curved fitting goes on the RH carb.

I know it sounds basic but have you got the right handlebars? If they are high bars it might explain why the cable is too short. Kev

[Kettletimes3]

I'm with Kev on this,
The uk model had low bars and the us had high.

[Alan H]

Or there's a knot in the first part of the cable.
Have you checked there isn't?
It's easily missed.

Post a pic of the bike (handlebars area) and we can tell better if you have the 'wrong' bars fitted, or the wrong bars for the handlebars and cables you do have.

[r3sc]

Hi Guys,

Many thanks for all the replies and help.

I currently have the curved fitting on the left hand carb but only because that's where it was on the old cable when I got the bike. I will change that this evening.

I will also look at the bars and see how they compare to the bars on my "K". I did notice last night that the cable wasn't screwed all the way into the bottom of the handlebar housing so I'll take that off again and try to screw that all the way in and see if that makes a difference.

Once again, thank you and I'll post when I have a resolution.

Regards

Pete.

[r3sc]

Hi Guys,
I've managed to get some time on the bike this weekend and have made a bit of progress so below is an update.

I checked the bars against another standard set that I had and they looked the same. I screwed the cable all the way into the handlebar housing but still had the same problem and when the bike ran it was massively over oiling. So, I removed the locknut from the oil pump cable and this allowed the pump control arm to go back to a normal'ish starting position and this seemed better.

However, when the throttle is opened fully the slides in the carbs still go a good way past the setting holes and the oil pump arm still goes way past the full throttle alignment lines.

At the moment the bike seems to be running ok with a normal amount of blue smoke but not sure what the long term effect could be with the excessively open throttles and oil pump.

Could I have an abnormal throttle tube that has a bigger cam/larger pull than standard??

It's all very strange!

Regards.

[barney01]

Hi
Just to clear something up. The stamp mark on the slides are just used to balance the three carbs and set the oil pump arm. They are not the maximum measurement. When all three marks are in the sight holes the oil pump arm should be adjusted to line up with the mark on the pump. This is a video for a 550 J but the set up is the same.
https://youtu.be/jJGl_hab3Bg

[canaletto5]

Literally, the only thing I can think of is that you have the cable ends the wrong way around on the throttle tube cam

[r3sc]

Hi Guys,

Thanks for the input. I do understand the relationship between the oil pump alignment marks and the throttle slide drillings but the manual I have states that the slide drillings should be at the top of the inspection holes on full throttle.

I'm going to strip the cable off again and triple check everything and get back to you.

It's good to have your continuing input.

Regards