Did you try the ether method I outlined above? It's helpful to confirm spark/timing/compression...if it runs on starting fluid we can then narrow the search...

 

Have you tried a fresh plug. You are putting the choke on when you try to start the bike.What is letting you know know you have fuel, a wet plug. Is it spinning over fast without change in sound even when you hold throttle wide open. Was this a fresh rebuild. If fresh rebuild sometimes good to hand choke the carb to start bike the first time. Trying to get a little more pertinent info from ya.

 

Got a 91 suzuki lt80 that I've been trying to get going for my kids but having a hard time getting it started. With the air filter assembly on it will just crank and crank. If I undo it from the carb and finger choke it, it fires right up. I just cleaned the air filter so I know it's ok. Any ideas please?

 

I'd clean the carb and do a compression check.

 

I have cleaned it a couple of times. When I got it the lt80 was all in bad shape. First time I opened the carb it was nasty, all crystalized in there. I let it soak in carb cleaner for a couple days then cleaned it but could still be plugged somewhere? When I do get it running it runs pretty until it nears top end of power then it falls flat. I'm thinking of ordering a new carb since they are pretty cheap and I'll see if I can round up a compression tester. Thanks lt80. I've seen you on many of these threads and I know you know your stuff on these quads.

 

You really need to remove the jets (especially the idle (pilot) jet and ensure the tiny holes are clear...everyone has a different idea of what a "good" carb cleaning is...for me, it's a complete breakdown of all removable parts, healthy run (20min) in a ultrasonic cleaner, inspection of all removed parts and then reassembly.


I leave no doubt about it's cleanliness...

 

Done that. Even put brand new jets in and still the same. What has me perplexed is the very first time I got it started it screamed. Since then it's not been the same which makes me wonder if something is plugged somewhere. I ordered a new carb to try out and will update when it shows up and is installed. After that first run is when it started to run sluggish which is when I pulled the carb off the first time and saw how nasty it was in there. I have not been able to get it to run the same since. It hadn't been ran in quite a while so inside the carb stunk really bad and moving parts where stuck like the float.

 

I also replaced the petcock with a regular one as I wondered if the vacuum petcock may be failing but it made no difference.

 

Ok so it still would not cold start with air filter housing but it would start with it on after letting it run for a few minutes. Also ran good with the housing on, it actually would Rev full throttle. Still gonna put the new carb and #90 jet in when it shows. It is slow to take off so I'm guessing rollers are probably worn on clutch? Or could still be carb issue?

 

Compression test and clutch maint now.I wouldn't worry about the 90 jet.