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Ty175 Throttle Response

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Had a problem with my sons TY175 today.

Was running great 'till a very wet New Years day trial, where is developed a bit of a cough and splutter.

Airbox was soaked when I took it apart, so cleaned the airbox, replaced the filter with a new one (probably needed a change anyway) and cleaned the carb. Nothing obvious in the carb.

Next trial out was today, where is had a distinct 'bog' off the bottom when opening the throttle. Also after stopping was really difficult to start.

The 'bog' was so bad that riding through a section, seemed ok but then on the uphill exit, it just died (almost like you had left the fuel tap off).

Decided to call it a day, again difficult to start (and had a little backfire before it did start again). When ticking over, open the throttle quite quick and it just dies.

Running electronic ignition.

Any ideas ?

Was planning to clean carb again , but any thoughts welcome

 

cheers

John

  • Author

Thanks for the response guys

Reeds seem OK (no gap) - but might be worth changing anyway ?

Just been stripping it down and a quick question - the inlet rubber onto the reed valve is offset (to the left hand side of the bike) by a significant amount and does not line up with the reed valve - is this normal ?

cheers

John

Thanks for the response guys

Reeds seem OK (no gap) - but might be worth changing anyway ?

Just been stripping it down and a quick question - the inlet rubber onto the reed valve is offset (to the left hand side of the bike) by a significant amount and does not line up with the reed valve - is this normal ?

cheers

John

 Yes it`s normal, but there is a mod with an rd 400 manifold.

 Also replace the small o ring on the nozzle and the o ring on the banjo bolt. 

Edited by lineaway

Pull the side cover and see if ignition is full of water also check the amount of oil in it and see if there's water in the oil. Change plug. Reclean carby again. Check flywheel key.

Bogging down, difficult to start, sounds like it's lean.

 

What does the plug look like?

 

I presume the autolube system has been removed?

If so, check the feed on the carb (small connection on the right side, just before the manifold joint), it should be blocked up or blanked off, if not it'll drawn in air.

 

Also check the float heights are set right, the float bowl inlet valve isn't sticking and the petcock isn't gummed up or blocked.

(there's a fine mesh filter on the internal end of the tap in the tank)

 

Check the head gasket isn't leaking.

 

After all that, you are probably looking at crankseals

reeds that are not broken and have no gap should not need changing.....your problem is more likely to be a passage way in the carb that has a droplet of water obstructing it or dirt is lodged in a jet etc clean carb thoroughly.and take off ignition cover and check for trapped water there.

 

I'd go with the above.

 

As it was running fine and the only thing you've added was a deluge of rain water, I'd stick to wet dirty carb and possibly water in ignition.

 

TY's like their pilot jet and passage ways clear otherwise they bog down on opening the throttle.

 

When you say you cleaned the carb out, have you stripped it down completely and given it a dosing of carb cleaner (remove and#39;O' rings first or you'll be sorry) then blown all the jets through with a compressor and then left it to dry indoors overnight? 

  • Author

Thanks for all the info and help.

easy things first, as mentioned above a good thorough carb clean first...

cheers

John

Could be any of the above but a weak point on the TY175 carb are the O rings especially the one around the main jet, they need to be intact and a good fit.

blocked pilot jet. I went two sizes up from standard and its less prone to blocking. Is your tank interior rusty? .... cleaned mine out by leaving it soaking in vinegar then coke for a few days .... came up spotless (rinse with petrol afterwards though). agree with comment on the carb O rings ... they do go past their sell by date and new ones make a world of difference. Also, clean your exhaust out - this also makes a huge difference (I burnt mine out on a small bonfire .... smoked a bit!)

  • Author

Update .... On cleaning the carb found out it has a 125 carb! Trial at the weekend was significantly better, however still not running right - now bogs a little under power ... 175 carb the correct route ??

Cheers

John

  • Author

Latest latest update - contacted the guy I bought it off and he had a mikuni 26 built with standard 175 jetting. Going to try a 175 carb I can borrow just to be sure - but may just need more cleaning ! (Ultrasonic ?)

Cheers

John

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