Hi guys, probably been asked 100 times before, but having problems getting my TY175 started and staying running.

Bought it to fix up and guy said it ran before being left on the shed for a while!

Will start with "start ya *******" down the bore or neat petrol), but wont keep running! sometimes get 2 turns round the garden before it blurs out!

Its driving me mental!

Have cleaned the carb many many many times! check check check!!!

Pilot jet not blocked! - check

Fuel changed and filtered -check

Reeds look perfect - check

Over 100 psi compression on dial - check

Float height within tolerances - check

Not smoking excessively so dont think its the oil seals - check

Any help or advice gratefully received!

Thanks

When running does it rev clean ?

Does lean out when it dies?

Or is it flooding then dies?

What Jets are in carb?

Check timing?

New points?

Point gap?

New condenser?

Petrol tank breather may be blocked. Take cap off next time and see if it restarts.

Have you checked and cleaned the fuel tap??

If its been stood a while chances are its full of resin.

Ive a haynes manual somewhere if you havent and want a read of it.

Carb jets may be clean but are all the passages in the carb clean?

Coujld you have powdery rust in the tank (often forms on a laid up bike) that clogs the in tank filter as soon as the bike runs. Anyone you can borrow a tank and carb off?

Disconnect the condenser - bike will rub OK for a while without it until points get dirty due to arcing.

Check HT and LT coils for resistance both with bike cold and just after it has run.

Points. Where the wire connects the spring they are riveted together. Corrosion can increase the resistance of this joint causing no or intermittent running. I have had this happen with brand new points - because they had laid on dealers shelf for many years.

My money is on the LT coil

If you're having to put fuel down plug hole to start it, I'd be looking at fuel starvation, is the float needle sticking? also as Dadof2 says are the passages in carb clear?

Have you removed float needle seat and give that passage a good blow out?

How did you clean the carb? if you used carb cleaner I hope you removed the rubber 'o' rings first they don't like carb cleaner, ultra sonic is best.

Laquer/resin in a carb is a pig to get rid of, carb cleaner doesn't touch it, either invest in a ultrasonic cleaner and some decent detergent or take the carb to a garage and get them to ultrasonically clean it and blow out the jets and passages with compressed air.

Thanks everyone.

Have checked the timing its spot on, cleaned points and tested condensor, maybe should renew them and check good connections etc.

When it runs it revs clean for a time then dies, does seem like fuel starvation??. when i strip the carb there is always fule in the bowl! I will check the jet sizes

Cleaned the carb with compressed air with all jets etc removed, has new fuel tap and I also changed the petrol in the tank.

Will give it another shot based on your advice and let you know if I,m still pulling my hair out!!

Thanks again guys.

The pilot circuit flows through two passages. One straight uo to the slide and the other in front of the slide. Both need to work. Also the o-ring on the main jet holder. Recently I re-cleaned a friends carb after he did, the pilot was still plugged up.

Sure sound like it not getting the fuel it needs.

When pulling the fuel line to the carb the fuel should run out in a steady stream. Not drip drip. If running good from the fuel line, that points to a carb problem. Will it stay running with the choke on? Try put A tube on the pilot jet hole and blowing threw it with your mouth, as stated above the jets can be clean but the passage way can be blocked. Also try to blow threw the feed line to the carb and make sure the needle for the flowed is not sticking. I had one that had a glob of junk behind the seat for the needle. Between the the in feed line and the needle seat.

Cleaned the carb with compressed air with all jets etc removed, has new fuel tap and I also changed the petrol in the tank.

Will give it another shot based on your advice and let you know if I,m still pulling my hair out!!

Thanks again guys.

A blow out with compressed air won't shift the old lacquer/resin, you may be able to see through a jet and think it's clean, but there will still be a coating of lacquer on the bore of any jet /passage.

I'd guess what is happening is that you blow it out, start bike up and a bit of lacquer becomes dislodged and blocks one of your orifices (ooo er missus) so you strip carb blow out again and the whole process repeats itself, hence the sudden hair loss.

Maplins do an ultrasonic cleaner for £30 + a bottle of seaclean £6. unfortunately the bowl isn't deep enough to get the whole carb in but just do it a bit at a time. Strip the carb and place all the jets in the cleaner with double dose of seaclean, put the cleaner through several cycles, change liquid and clean again several more times, rinse in clean water, blow out the jets etc and leave to dry overnight.

With the carb body, again double dose of seaclean and put it through several cycles rotating the carb with each cycle, you'll be surprised at how clean it becomes and think you have a new carb, now replace the fluid in the cleaner and do several more cycles, rinse in clean water, blow out all the passages and leave to dry overnight.

It might seem a lot of cleaning but it's definitely worth it.

Reassemble carb, fit to bike, turn fuel on, pull out choke, wait 30 secs, kick it over and smile.

Word of warning on ultrasonic cleaner don't put your fingers in the fluid whilst it going through a cycle, don't bother with the plastic trays (you don't get such a good clean) just put items to be cleaned straight in the metal bowl.

Change the O ring that seals against the float bowl, find one that is a tight fit they come in different thicknesses Pull the bowl off the carb body you will see the one it goes into the bottom of the bowl. This O ring can cause running issues when worn or damaged.

Edited November 8, 201411 yr by trialsrfun

Havent got another update as I holed the side casing with my kickstart !!!!!!! So away getting welded!!!

Watch this space!

When sorting such problems find it handy to add an automotive condenser under the tank.

Sometimes a fix.

Cheap insurance.

Larry

Are you running it on pre mix or does the bike still have the oilpump.If on pre mix make shure that you closed the little hole in the carb on the right side where normaly the oilpump hose comes in.