Carter interceptor 250 won't start.

[Dallastx]

Hello everyone. I purchased an 07 carter 250 interceptor. Previous owner said it quit running. He said he could get it to start it would idle but then die and would not fire up again for a few days. It's in good shape so I went ahead and bought it. I have bought a couple of carbide 150s and with help from this forum and reading almost every page and piece of advice they are both running strong to date. I even bought a 250cc buggy with the Cn250 engine and that is running great as well. This buggy however has me completely stumped. The others had either electrical no spark issues or needed valves adjusted along with parts replaced. This carter buggy has spark. The fuel tank was full of bad fuel and carb was gummed up. I cleaned out tank, and completed cleaned out carb. With the other buggys I was able to at least spray some carb cleaner at this point and get something out of them. Nothing here. I have adjusted the valves as per a scooter sym 250 spec sheet. Intake .10 mm(.004) and exhaust .15mm(.006). I haven't really been able to find much on this buggy. I guess I should've looked around for info first but it looks awesome and is in better condition than any of the other buggies I have. I hope someone can help me out here. The only thing I am unsure of is the carb that's on it. P/o said he bout a new one bit I'm not sure if it's the right one or if it matters. As in should it at least start and run bad.

[Dallastx]

This also bothers me. May not be an issue but this is the only wire not hooked up to anything. Everything else looks as though it goes where it belongs. The harness come out from behind cvt cover. And the blue/white wire hook up beside carb on back of head where water line goes in. Temp sensor maybe? Again, it does have spark so I'm assuming electrical is fine. The fuel pump works because I can see fuel get sucked up to the carb. When I put my hand over carb opening it gets wet with fuel. I have not checked for compression after adjusting valves. They were both closed tight. I got excited when I found that out. I thought it was going to fire up after but no luck. It clearly creates a vacuum at the carb opening and blows finger out of spark plug hole.

[Dallastx]

This is what is also weird on the carb. None of my other buggies have one like this so its new to me. My quad doesn't have this type of carb either. I can pull up on the cable and it pulls the black sleeve inside the carb with it. And the nuts on the cable end don't seem to adjust anything. Thanks. Sorry if it's too much I'm just at a loss here.

[SYCARMS]

What brand is the carb?

[Dallastx]

Thank you for your reply. I have attached a pic of the side of the carb. Those are the only markings on it. Looks to be a generic $20 carb from eBay. When I opened it up to clean it it had a #90 main jet. Thought it was odd so I swapped it out for a 120. My 150s run 125s and the 250 does well with a 130. I figured 120 was a good starting point. Although from what I understand that alone shouldn't keep it from at least starting. Or wanting to. I also removed the intake "manifold" and the gasket that goes on the head looked bad and brittle so I swapped that out with a new much rounder one. I was hoping it was sucking air from there causing my problem but no luck. All it does is turn over. When I cover the carb opening partially with my hand the engine sounds a bit different. Like it picks up speed turning over if that makes any sense. As stated before I can clearly see a spark both if I touch the spark plug thread to muffler And if I just hold spark close to muffler I can see it jump to muffler. Hope I make sense. Sorry if I write a lot in just trying to paint a full picture of what I've done and tried. I also squirted a bit of fuel in the spark plug hole and replaced spark plug. Cranked it like before. And this time after a few seconds it made a backfire type sound out of the muffler. Just one quick "boom". But that was it. Just kept turning over.

[SYCARMS]

What color was the spark?

[Dallastx]

Whitish blue ish.

[SYCARMS]

The carb looks to be a Chinese copy of a Keihn. Your carb is marked with a K and standard of Japan. The Keihn carb will be marked Keihn Japan. It could be your carb. After trying to start, pull the plug and see if it is wet. It could be your getting too much gas. You cannot compare the CV carb like used on the 150 to this slide carb. To tune a CV carb there are only 2 mods to make and that is main jet and pilot jet. On a slide carb to tune you have the main and pilot jets but you also have the needle jet and jet needle, slide and needle/seat. I have no idea what the setup of this carb is or the setup on the original carb which I'm not 100% correct but I believe it was a slide carb as well. Just recently I replaced the carb on a Kawasaki 250. It was a Mikuni carb 26mm. It was built specially for Kawasaki and is slightly different from the standard VM-26 Mikuni. The replacement carb only available through Kawasaki was almost 400.00 so I went with the VM-26 Mikuni. Could not get it to start so I played with jeting and got it to run but it blew black smoke and choked at high throttle. Long story short is I had to reduce the size of the needle/seat than rejet.Go to Keihn's web site and try to identify one of their carbs to yours. Once you find their model like yours they should have a parts breakdown of that carb. Compare your parts with theirs to see if they might interchange, than look for and download a tune up manual for that model carb. Usually Keihn will have either the manual or a link to one. But first we need to know if after trying to start, is the plug wet? If just the electrode is wet it should fire if you have a good spark. If the porcelain and threads are wet as well than you have too much fuel to fire off.