DT175 Yamaha Enduro issues

[F5 Dave]

Indeed that is unusual. if one had the carb in your hand & pushed a bit of plastic hose against the carb intake (small but open hole at carb bellmouth) & blew, assuming a decent seal it shouldn't pass wind (Oo-er). then when you open the choke it should. If you shine a light up there you may see the choke bottoming. Take choke out & check it hasn't got any grit down there. its just a sliding shaft with a lever & spring mechanism.

[Yakman12]

Choke is good, replaced the float jet and seat.

.... still running like a bag of crap at 50km round town, like seriously crap.

I really don't know what else to check on this thing.

[F5 Dave]

humour us & change the plug again, actually while you're about it check the plug cap with a meter & see that it is about 5-7k resistance.

[Yakman12]

Yeah I'm ahead of you, already changed the plug after I did the float valve.

Will check the resistance, it is a brand-new spark lead mind you.

Wonder if it is an ignition timing thing?

[F5 Dave]

Timing will be fixed where the plate bolts on & CDI ignition in 1980 for sure. Whether all is in good order. . .


SCREECH. . .Wait up, sorry the spark lead is new?

Explain please. Please tell me you haven't replaced the plug lead with car type carbon lead?

[Yakman12]

No I haven't replaced the spark lead myself... but it does have a new shiny one from the previous owner, he had it replaced by a mechanic so I presumed it would be correct?

How do I tell if it is a car-type carbon lead? Why would this be an issue?

[F5 Dave]

take off (twist) the spark plug cap, should be strands of copper wire, then all good, its bike stuff.

Strange though as most coils have bonded leads, not that many are replaceable. Some 4 stroke coils have replacable & people buy car type silicon (carbon inner) leads which look pretty but are unsuitable for tiny bike coils & cause misfires.

I'd be interesting in the coil if its std.

[trapster66]

if it runs fine flat out, the main is o.k. starts good?, pilot is o.k. mid range riding is the needle jet responsibility, have you tried altering needle hieght ?

[trapster66]

nevermind my lasty post mate looks like you would have addressed that issue(needle hieght) a while back,
F5 Dave sounz like he'z on the money. cheers

[Yakman12]

Actually you are nearly on the money!

I finally lost the plot and took the dam bike to the guys at Boyle Kawasaki.

They figured out that the needle has worn the casing the of the needle jet bit (the seat the needle sits inside).

The quick fix was to lean it right out (20 Pilot) and lean out the needle by another notch.

I was on the right track with it running rich in the bottom end, I just didn't go far enough.

The ultimate fix will be a new needle and casing.

Should also be mentioned the choke may have been not closing properly, which the chaps at Boyles also sorted (but said they didn't seem to think that was the problem).

All in all she is now running perfectly, thank god!

[gammaguy]

Hi thanks for the replies!

Woodman I have pulled out the reed valves and look OK, they seem to be sealing fine and opening OK, is there anything specific I should be looking for in stuffed reed valves?

Padmei, I'll have a look at the state of the exhaust and see if that is an issue. I haven't had any broken starters yet haha! Although the bike only has 9,000kms on it (imported from South Africa) so not overly surprising!

Recondition your carburetor

Enjoy

[F5 Dave]

Hah, funny, I've given that advice many times but didn't even think of it this time.

Look down the tube with a bright torch & check for ovality, just a little will create a path for big wet droplets which are hard to burn. Seen a KDX which was dreadful & my old RF did it pretty bad.

I ended up making some brass inserts & drill & supergluing them into the tube after carefully drilling them to the right size (actually I paid an engineer who could work that accurately on small stuff, it was well out of the scope of my lathe).

[Yakman12]

Recondition your carburetor

Enjoy

cool...

thanks for that.