Davidmdx25

You never posted an update of what you did. I’m aging the exact same issue

I just cleaned the carbs very well with carb cleaner and air about 2 weeks ago. I don’t have a fuel filter either. I get a little bit of fuel coming out of the over flow lines sometimes. And I see fuel draining through my lines that go into the carbs so I’m sure it’s getting fuel to the carbs.

Ok so here’s an update. i put my premix in an empty water bottle and poked a small hole through the lid. WOT I squeezed a bit in on both carbs. Sounded like it wanted to start but didn’t. I squeezed a little bit more in and BOOM! Started up. Got on it and it would almost have intermittent power. It would pick up and then kinda loose all power, then try to pick up but then loose power again and so on... then it bogged out and wouldn’t start by just kicking it. It was on for a total of about 3 minutes

Yea I checked them when I did the top end. There was a tiny bit of light through one of the pedals so I unscrewed it and flipped it upside down to try and close the gap. However, there was still a very small gap. But it ran fine for a bit that’s what I don’t understand

I have not touched the fly wheel side but I’ll look into it this weekend ! This is so frustrating

Ok so here’s and update. Compression tested 115 on left cylinder and 120 on right. Pulled both spark to make sure I was getting spark and I am. I hit the kill switch to “off” and stopped getting spark. That proved that my kill switch is good. And compression is good. What else can I look for ?

Yes it kicks over just won’t start. Yamaha cylinders

I didn’t think it could be that since I shut it off. It didn’t shut off on its own

Correct not oem. Wiseco pistons. And the 125 psi was before !

Here is an order of events. First I rebuild top end when I first purchased as it was not running. I did new cylinders (stock) new pistons and head (oem stock) and rebuild the carbs to stock pilots and mains, needle on 3rd clip. Bike would not fire at the time so I tested for spark, compression and did leak down. All tested good. I pull the carbs again and cleaned them really good (again) and went 2 turns out on air screws and 3 turns in on idle screws (tors delete). Bike finally fired and ran great at this point but then got stuck in 1st gear. It only ran for about 15 minutes before this happened. So the following weekend I took off the side cover, fixed the star, replaced the clutch and put it back together. It didn’t start kicking it. So I pushed it and got it to fire. Went around the neighborhood for 5 mins tops with no coolant. I turned it off and heard a sizzling sound. Since then, I’ve added coolant and did a oil change. Now it won’t fire by kicking it or even pushing it. So I ordered new carbs on amazon (MOTOKU) brand. Installed and still no Luck.

cross over tube is definitely in. I actually just replaced it with a clear hose since the old one was black and not see-through. When I did the star I also installed a new oem clutch basket and clutch. Made sure the primary gear spun freely. Put a new gasket on and installed clutch side cover. I must add, before doing this I rebuilt the carbs and then it started right up. It lost all its coolant as I had a drip from a hose. I decided to still ride it around the neighborhood for about 5 minutes tops. When I hit the kill switch to shit it off, I heard almost like a sizzling sound of it being hot.

How do I test for weak spark?

Hi guys, I’m new to the site. I hear this website has all the answers so here I go. I’m sorry if this has been asked before. I have a new top end. New cylinder and new piston. I did a compression test and got 125 out both cylinders. New spark plugs. Fresh fuel (yamalube 32:1). New stock carbs as well. New AirPod filters. Stock chambers with some aftermarket pipes(not sure of brand). I had it running great finally after rebuilding the carbs and then my shifter got stuck in 1st gear and wouldn’t change. Found out it was the shift star. I fixed that and put it back together now it won’t start at all. I even tried push starting it no luck. I checked for spark and compression. Both are good. Any ideas ?