GT250A Engine oil pump adjustment

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Micron
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GT250A Engine oil pump adjustment

Post by Micron »

Now I'm not one to be afraid to ask if I'm not too sure about something, and this is no different :lol:

I read the description in the Haynes manual on how to adjust the oil pump, but it doesn't appear to work correctly, or I'm not doing it correctly? :oops: :oops:


When I open the throttle as described the lines do not line up as they should, it was a few days ago that I looked, but if I remember correctly the lines just never line up, even with the throttle fully open?

Any guidance would be appreciated

Thanks

Trev
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kb75ts250
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Re: GT250A Engine oil pump adjustment

Post by kb75ts250 »

Does the lever move as you turn the throttle? Do the lines get close to lining up? Or go past?
Currently - 75 TS250, 02 Kaw ZX-6R
Previously - 70 T350, 71 TS250, 72 GT380, 72 TS125, 72 TS250, 75 Yam YZ360B, 72 GT380 diy cafe racer, 80 GS750, 73 TS185, 82 GS1100
Micron
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Re: GT250A Engine oil pump adjustment

Post by Micron »

kb75ts250 wrote:Does the lever move as you turn the throttle? Do the lines get close to lining up? Or go past?

Hi, It does move, and I read the process again, at least three times, and I think that I may have cracked it, however it does appear to be very far out of the adjustment thread, I don't believe that there is much left in the casing
It does go past the line if you open the throttle fully open,

thank you for your reply and question, it made me think a bit more about what I did previously :up: 8)
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kb75ts250
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Re: GT250A Engine oil pump adjustment

Post by kb75ts250 »

That's good that the lever moves. I'm sure the Haynes manual has the correct procedure. It's really very easy and a good way to learn something about your bike. If you get someone else to hold your throttle wide open you can adjust the oil pump cable and watch as the lever moves and lines get closer/further. If you can post a pic here or on imgr I'll be happy to take a look for you.
Currently - 75 TS250, 02 Kaw ZX-6R
Previously - 70 T350, 71 TS250, 72 GT380, 72 TS125, 72 TS250, 75 Yam YZ360B, 72 GT380 diy cafe racer, 80 GS750, 73 TS185, 82 GS1100
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jabcb
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Re: GT250A Engine oil pump adjustment

Post by jabcb »

What is the adjustment procedure in the Haynes manual?
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Micron
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Re: GT250A Engine oil pump adjustment

Post by Micron »

jabcb wrote:What is the adjustment procedure in the Haynes manual?

Remove the screw from the side of the RH Carb, so you can see the slide through the opening.
Open the throttle, so the mark on the slide is at the top of the hole.
Check to see if the line on the moving part at the pump, lines up with the line on the pump, adjust as required.

Or words very similar?
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kb75ts250
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Re: GT250A Engine oil pump adjustment

Post by kb75ts250 »

Micron wrote:
jabcb wrote:What is the adjustment procedure in the Haynes manual?

Remove the screw from the side of the RH Carb, so you can see the slide through the opening.
Open the throttle, so the mark on the slide is at the top of the hole.
Check to see if the line on the moving part at the pump, lines up with the line on the pump, adjust as required.

Or words very similar?
OK, I stand corrected regarding my post above. Typically Suzuki oil pumps were always adjusted so the pump and lever marks line up at full throttle. Change the words above "hold the throttle wide open" to "Open the throttle, so the mark on the slide is at the top of the hole". It's important and that means the marks going past alignment at full throttle may be normal. Nontheless, having someone else hold the throttle for you while you adjust the cable is helpful.
Currently - 75 TS250, 02 Kaw ZX-6R
Previously - 70 T350, 71 TS250, 72 GT380, 72 TS125, 72 TS250, 75 Yam YZ360B, 72 GT380 diy cafe racer, 80 GS750, 73 TS185, 82 GS1100
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Re: GT250A Engine oil pump adjustment

Post by sportston »

You said it was a long way out of adjustment....
Have you had the carbs off recently? Are the carbs balanced?
Before you check the oil pump adjustment you should make sure you static balance the carbs.
Without the engine running, make sure that they both start to open at the same time and both reach full throttle at precisely the same time (note: poorly balanced idle speed screws may make it appear as if they are not opening at the same time, that is why it is good to check the slide near the top of its travel is even on both carbs too. Its no big deal to adjust the idle speed again later if you find you need to turn the idle screws out to help you balance the cable operation up).
Also make sure you don't have loads of slack on the throttle cables (none is bad, a little is good, a lot is bad) and tighten both lock nuts after adjustment and double check adjustment.
Only after you have done this should you attempt to set the oil pump cable adjustment.
When you set the oil pump adjustment, don't forget to tighten the lock nut on the cable adjustment and recheck afterwards.
Loose lock nuts can cost engines!
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Re: GT250A Engine oil pump adjustment

Post by Micron »

sportston wrote:You said it was a long way out of adjustment....
Have you had the carbs off recently? Are the carbs balanced?
Before you check the oil pump adjustment you should make sure you static balance the carbs.
Without the engine running, make sure that they both start to open at the same time and both reach full throttle at precisely the same time (note: poorly balanced idle speed screws may make it appear as if they are not opening at the same time, that is why it is good to check the slide near the top of its travel is even on both carbs too. Its no big deal to adjust the idle speed again later if you find you need to turn the idle screws out to help you balance the cable operation up).
Also make sure you don't have loads of slack on the throttle cables (none is bad, a little is good, a lot is bad) and tighten both lock nuts after adjustment and double check adjustment.
Only after you have done this should you attempt to set the oil pump cable adjustment.
When you set the oil pump adjustment, don't forget to tighten the lock nut on the cable adjustment and recheck afterwards.
Loose lock nuts can cost engines!
Yes, I have had them off, and did balance them before trying the pump adjustment this time. Not sure how slack they are, I will add it to the list of things to do, lol

I have tightened all of the lock nuts on the carbs and oil pump adjuster.
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Re: GT250A Engine oil pump adjustment

Post by ConnerVT »

Don't know if mentioned before: OEM or aftermarket cable? Correct cable for model/year?
Micron
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Re: GT250A Engine oil pump adjustment

Post by Micron »

ConnerVT wrote:Don't know if mentioned before: OEM or aftermarket cable? Correct cable for model/year?

No idea on any of that :?: :?: :?:
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Re: GT250A Engine oil pump adjustment

Post by ConnerVT »

That's what makes projects like this fun - the unknown. :ssh:

The oil pump adjustment *should* be simple. You are just setting the pump for maximum flow (the alignment marks on the pump) when at full throttle (or, in this case, at the alignment mark on the carb).

In a perfect world, the amount of travel between closed throttle and full throttle is exactly the same as that of the oil pumps arm fully back and the alignment mark. On my T500, at closed throttle there is a bit of slack at the oil pump, taking about a 1/8 (or so) turn of the throttle before the oil pump arm begins to move. I see this as a non-issue, as the pump delivers oil at all times, even when the arm is all the way back.

It seems that your issue may be that, on the throttle cable end going to the pump, the distance between the cable sleeve and the inner cable end may be too long. This would make adjustment problematic. Causes could be improper adjustment of carburetor (cable adjusted correctly, with proper free play), missing/incorrect/improperly installed throttle and or throttle cable, stretched (unlikely)/ wrong model/bad designed aftermarket cable.

The most important thing is to first confirm that the throttle setup is correct. Check throttle control is assembled correctly, adjust carburetor, confirm correct free play. Then revisit the oil pump adjustment.
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Re: GT250A Engine oil pump adjustment

Post by sportston »

ConnerVT wrote: The most important thing is to first confirm that the throttle setup is correct. Check throttle control is assembled correctly, adjust carburetor, confirm correct free play. Then revisit the oil pump adjustment.
Thanks for the back-up Connor.
I also agree that it doesn't matter too much what cable you have, genuine or pattern. So long as it is moving freely and is correctly adjusted. If it is completely impossible to adjust correctly, due to manufacturing defect or similar, replace it. But if it works, don't knock it.
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