Superjet spark plugs opinion?

[Killerpirate]

Do these spark plugs look like my engine in running lean? Spark plugs are 2 weeks old and used for 3 times i think. And if so, whats te solution? I checked the settings of the carb and they are correct
Should i just turn the main jet a little further out.
Stock 2016 superjet. I have the feeling that it lean seized on me 2 times past weeks. Bougt the sj couple months ago, but when i run it long and hard on the track it suddendly died. Like engine stopped instandly. First time it was hard to start, second time it fired right up after.

Compression is low (on cold engine, didnt do anything to prepare the compression test) but equal on both cylinders (100psi). I mix oil at 40:1, or more

 

[SuperJet-Dave]

Compression is way too low at 100 psi. Should be around 150. I would test again and/or use a different tester. Can’t imagine how it would run well at all at 100 psi. Plugs do look like it may be running lean, but the compression would need to be assessed first.
Good luck

 

[mikidymac]

Was it a Harbor Freight tester?

 

[fastgtfairlane]

the color doesnt look bad really but the only way to get an accurate plug reading is with a 10x magnifying glass so you can really see what the ground electrode looks like as well as down in the plug. also need to shut the engine down with the engine running at max throttle because as soon as you let off and the engine is still running, it will throw the plug reading off. chocolate brown color is ideal. whiteish color would indicate too much heat or lean condition.

 

[kevbo]

You engine is not damaged if both cylinders read the same, one will always fail first saving the other. Those are #7 plugs, they will be lighter and drier than #8 for a given carb tune. You are probably okay if both plugs look the same and the ski is running good. If you want to tune, open the top screws until it loses power and slowly close them until it doesn't run any better. A low tank will let air in the fuel line and cause hesitation or stoppage, especially with the stock pilot/popoff settings.

 

[Killerpirate]

Well, thats part of the problem. It runs very well, (sometimes holds back for .5 sec when you hit the throttle 100% and when engine is cold it will stall a couple of times when trying to get on plane. But after couple of seconds it works great. I just have to be careful with the throttle during the first drive of the day.
But it died on me twice now, during a hard long run. Thats why i suspect lean seizure, but im not sure. Plugs didnt really say if its running lean.

 

[kevbo]

Lowering your popoff pressure a little will richen up the low end and make it come to life quicker when cold. Using the reserve pickup and keeping the tank at least 1/2 full will minimize air in the line on long full throttle runs. I found it so annoying that I installed a second pump and an air separator. Now I can run the tank bone dry before it quits.

 

[Killerpirate]

How do i adjust the popoff pressure? By adjusting the screws?

 

[kevbo]

How do i adjust the popoff pressure? By adjusting the screws?

Change the spring holding the regulator needle closed. Do a little research on this. you have to disassemble the carbs. Dont delve into it unless you are really interested in maintenance and tuning.

 

[RENDERGOD]

Lowering your popoff pressure a little will richen up the low end and make it come to life quicker when cold. Using the reserve pickup and keeping the tank at least 1/2 full will minimize air in the line on long full throttle runs. I found it so annoying that I installed a second pump and an air separator. Now I can run the tank bone dry before it quits.

What's involved in installing a second pump and / or a air separator. I get air sometimes when fuel gets down to a third in rough water and sh#t myself waiting for a seizure. I was going to try clunks out of desperation.

 

[kevbo]

Most people use a vertically mounted tube for a header tank. The inlet and return line is on top, the carb line near the bottom. A separate pump is required to circulate fuel through the little tank. This way the carb line never get air in it. Mount the pump higher than the crankcase so any liquid in the pulse line can drain back.

 

[RENDERGOD]

Most people use a vertically mounted tube for a header tank. The inlet and return line is on top, the carb line near the bottom. A separate pump is required to circulate fuel through the little tank. This way the carb line never get air in it. Mount the pump higher than the crankcase so any liquid in the pulse line can drain back.

Do you need to drill for a second pulse line, or just tee off existing?have you got a picture for reference? Are there any threads on this?
Sorry. Didn't mean to jack the thread

 

[E350]

Lowering your popoff pressure a little will richen up the low end and make it come to life quicker when cold. Using the reserve pickup and keeping the tank at least 1/2 full will minimize air in the line on long full throttle runs. I found it so annoying that I installed a second pump and an air separator. Now I can run the tank bone dry before it quits.

Photos or sourcing for second pump and for air separator?

 

[E350]

Wow! Looks like Group K could build a high pressure common rail fuel injected engine!

 

[kevbo]

I made this unit 12 years ago, still works perfectly. I found some nice ones used on gokarts, they are about half as long as my homemade part.

 

[RENDERGOD]

That looks like an easy option. Would it work without the xtra pump? Any other gurus feel free to chime in.