Qt50 bogging an running hot

Hi i have a qt50 yamaha with yt60 jug pw80 carb an hicomphead

First issue is when i start it it runs good but idles high like it has an airleak an will bog out when at WOT. It runs good if i give it 1/4 throttle repetitively but anymore an it bogs.

Another thing is it runs hot i run premix just to be safe but still its running hot

Any ideas on what could cause this

It has a 110 jet an hiflow filter an hiflowexhaust

Re: Qt50 bogging an running hot

matt boda1nz /

What is your compression? What color is your plug? How are you checking for air leaks?

Re: Qt50 bogging an running hot

Compression seems a little on the low side. Plug was dark an wet on the edges an spraying carbcleaner around the intake an carb..ect

Would low compression make it run hot?

Re: Qt50 bogging an running hot

matt boda1nz /

Yeah.. your rings may be shot causing burnt gases to blow by the rings, effectively heating up the cool gases behind the piston. Check your compression. Use the correct tester. Google compression tester mopedarmy.com

Re: Qt50 bogging an running hot

matt boda1nz /

Is this a new kit?

Re: Qt50 bogging an running hot

Used kit. An yeah it must be the rings then cause it seems to have low compression compared to my 70cc tomos..

Ha anyone interested in buying it? I dont want to put anymore $ into this

Re: Qt50 bogging an running hot

Heres a pic.

image.jpg

Re: Qt50 bogging an running hot

Clogged exhaust port or exhaust will do it. don-ohio

Re: Qt50 bogging an running hot

My towny has always run hot. Even hotter with its MLM pipe.

I'm replacing the crank seals on all 3 of my Yamaha engines.... i swear they all went bad at the same time.

with 1st engine, the seals were very hard and popped right out with almost no effort.

i tried replacing the rings first but they kept seizing.

special tools: piston stop, circlip pliers, and the flywheel puller. its the same as vintage Yamaha motorcycles, metric and reverse thread (a small 3 jaw puller would probably work too)

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