Jd101506

My major problem was working on two different quads, which were damn near identical in the first place. Confusing D7EA and D8EA plugs, near identical filters, near identical carbs… I have no problem admitting I was wrong or that I was the big dummy here. Definitely learned a lot, got two free fourwheelers up and running for under 800$ all in, and got me active on here so I’ll consider it a win. like I said above I really appreciate everyone’s patience. It definitely tried mine… 😆

Measure twice post on the forums once? 🙃

WELL. I think I solved it. So first off, I had my neighbor test my fuel as hes a mechanic, he has some kind of chromotograph and measured a sample of my oil. A VERY slight amount of fuel, but again this quad has something like 3.6quarts so its quite a lot. Couldn't sleep for a time last night so I started pawing through the manual. I realized two things. First, I installed my air intake filter incorrectly. When I got the quad, the airbox was PACKED full of mouse nest, this also means the original foam filter was toast, melted, eaten, completely gone. So when I went to reinstall, I didn't realize that I could take apart the air intake plastic shroud. I looked at it briefly and it LOOKED like it was a rivet in one side holding the plastic shroud to the guide for the mount in the box. So the ONLY way this could have been mounted was reversing the filter and installing it backwards... Which would NORMALLY be fine, but the foam filters I bought had quite a lot of glue on one end and I wonder if it was blocking the air flow or causing erratic running. Either way, I corrected this and it seems quite a bit better. Second, I think you guys hit the nail on the head. When I originally ordered the email carbs I ordered the correct PNs for each the LT300E and the LT4WD. Now they are the SAME slide style carb, but as @Gwbarm noted the jets are different. The LT300E takes a 13200-41B31 and the LT4WD takes a 13200-19B02. Again, I ordered these carbs from the SAME seller, on the SAME day, and they arrived on the SAME day to my house.... You can see where this is going. When I got it in, I had the fuel pump ready to go for the LT300 but not the LT4WD, so I left that one in the box. Installed the LT300 carb and boom! Went like it should and it was great. I DID notice on occasion, that when coming off a hard throttle I'd have a little bit of a RPM drop and every once in awhile it would stall. I didn't think too much of it since I haven't really put a lot of effort into that quad, and figured I needed a new plug and all that. So later, when the replacement fuel pump for the LT4WD arrived, I installed that and had all the following issues... So after ALL these issues and everything else... I figured I must have screwed up somewhere. So today, I parked them both next to each other and setup two VERY obviously different stations and I removed the carbs from BOTH Suzukis. I pulled the LT300e, and took a look at the pilot and the main. The 300e had a 98 main installed and a pilot listed with a 41. Thought this was weird because it was basically down the middle of the CV and slide carbs for the LT4wd... When I pulled the carb that was ON the LT4WD, it had a 112.5 main and a 20 pilot. I slapped my forehead and realized my mistake. What I DID do after, is I swapped the carbs, put the correct 112.5 and 20 on the LT300e, it fired RIGHT up and runs around the yard with no hesitation and ZERO issues. It sounds great! Because the main and pilot are SLIGHTLY off the book... I took the Shindy carb kit jets OUT of the original carb and installed in the ebay carb. Adjusted my slide/throttle and my mixture to factory. (Did this on both). Reinstalled, and MAN, it fired RIGHT up and idles like brand new. I'm attaching a video as a final proof. I double checked the overflow, and I double checked the inside of the carb after riding around for awhile and both were dry! I think I am reaching the end of my issues... Only thing now I noticed is that my speedo doesn't work so I'll have to figure that out. I have a lot of cleaning and other things to do but I am REALLY happy with how it runs! Thank you guys SO much for all your help with my issues during this! I really appreciate your guidance and patience.

Oh and while I was messing around I did a compression test just to be sure I wasn’t having bigger issues. Seems like 165 throttle open. So that’s positive!

Good info! The one that came off the Quadrunner is a VM24, so when I ordered the replacement carbs I used the Suzuki parts website and ordered 13200-19B02. Same deal for the Kipa carb. Is there a slick test I can do on the oil to see if there’s fuel in it? I’m second guessing myself that it has fuel in it. I tried the cardboard test and didn’t noticing any rings forming. The smell isn’t bad enough for me to immediately say I’ve got a big problem but that thing takes a ton of oil compared to my LT300 so it could have a bit in it and I dunno if I’d know.

No idea if this helps or hurts my case but I pulled a small bottle pump out and put some pressure on the carb. I would imagine this pumps more pressure into the carb than that fuel pump possibly could. It seems to hold pressure. I realized as I was removing this carb that the drain for the carb was kinked. So I would imagine if this TRIED to drain it wouldn’t have. The rubber hose was folded over on itself and wouldn’t let any fuel past. It’s encouraging that when I put that pressure on it, it came out in a steady stream and then abruptly ended. Tells me the seat and needle are doing something relatively right. I took a piece of vinyl hose and tried to blow through it. I know I can probably only put maybe 2psi to it blowing myself but nothing came out. I’m trying to figure out how I can make a 5psi pressure system to test the float and needle. thoughts?

I have the original carb for the LT4WD. All of these LT4WD models from 85-98 have fuel pumps. They have to, there is no way to gravity feed any fuel to them. I also removed an original Mikuni carb from this LT4WD when I started working on it because it was seized. I know for 100% fact this Suzuki has and needs a fuel pump. I also know for 100% fact that I have the right jets and needles in this carb because I matched the new Shindy ones to the ones that came out of the Mikuni from this bike that wasn’t salvageable. im using Suzuki parts warehouse to buy said parts. The part number for the eBay carb, Amazon carb both pulled from my bike, my year page that was mentioned in screenshots above. I’ll add my vin in here so you can double check I’m not horsing you around. For what it’s worth my LT300 is running great with an eBay carb and a Kipa fuel pump. I don’t know if it was a lightening strike or what, but both machines have and require the same style of carb (Slide style, NOT CV) and both use a variation of the same fuel pump. Im not trying to be an idiot here, I just can’t get this thing to not overfuel itself no matter what I do. I just got bored and pulled the slide out of the Mikuni and man, there’s fuel just sitting in the top there. Wild. Added a photo. Side note; what’s a sure fire way to test for fuel in oil? I’m second guessing if I smell fuel in it or if I’m just smelling the overflow from earlier.

I’m using the needle and seat that came with the shindy kit for the LT4WD. I’ve never used anything but the proper needle and seat which is why I’m confused as to what you are asking.

Super, thanks. I'll take a look at the vent and see what I can see. And yep, I have the slide carb in the middle diagram. The shindy kit I had replaced the jets with exactly the ones you mentioned. 100 and the 22.5. @Mech Ok, just wanted to check and make sure I wasn't missing something. So to confirm: At this point you would adjust the tang on the float needle to be more aggressive to prevent the flooding?

I guess at this point I'm just not sure how to do it. Four different carbs and they all seem to do the same thing. I guess tomorrow I will pull the OEM carb and check the floats again. The tang on the float, I assume I bend it TOWARDS the needle to increase the amount of pressure on the needle? It just seems impossible to me that all four carbs would have the same symptoms but from a technical standpoint it does make sense that the needle isn't doing it. I MAY swap my eBay carb back in because I can adjust the tang and test it outside the ATV using the vacuum from the other one. And the ebay one and the OEM one seem to function identically. One question: The needle itself on the slide of the carb. Would any adjustment to that needle help me? I noticed that the KIPA carb would run at high RPM and my throttle cable was tighter using that than the ebay or OEM... I assume that needle ONLY impacts RPM and not the mixture/how much fuel is going into the engine?

Did you happen to see the video I posted? Any idea about why the fuel would be coming out of that breather? Mech is right. The crankcase may be part of the issue but it doesn’t explain the fuel. Unless the crankcase is causing extreme vacuum somewhere? Anyone have any idea where the crankcase breather is on these LT4WD?

ok so a new data point! I messed with the carbs a bit today. I tried using the carb that I had on it previous and tried to pump fuel into it to flood it. I couldn’t get it to flood! No matter which way I turn it or anything it will not flood. I tested this by taking the old carb, pre filling it with a little bit of fuel, and cranking the engine over with the plug wire off. It pumps fuel like it should, and I can’t make it flood. Now here’s where it’s getting interesting. I noticing my oil level was a little high so I went ahead and I pulled some oil out. After I said screw it let’s try and ride it around a little. Now I left the air box cover off and I left the breather tube for the carb off. it ran around great. Like, how it should. I was astonished! that’s when I realized I forgot to put the oil cap back on. I panicked. Stopped the quad and ran back inside and grabbed it, screwed it back in and started it back up… Wellnit ran great again for about a minute… Now it is doing the same thing as before and the carb has fuel burping back out of the breather! im attaching a video. it got me thinking though… where is the crankcase breather on these? Maybe mine is plugged and as it generates heat and runs it slowly pressurized and pulls fuel hard from the carb and dies? Is there a way to test this? I noticed one breather is missing the little snorkels they come with. and @Gwbarm the carb that is currently on here is from a LT300e that I have. It’s a known ‘good’ carb but I installed the Shink rebuild kit with proper jets for the LT4WD. So far it’s functioning the same as the eBay carb, which I tested on the LT300 and that works fine. IMG_7733.mov

When I run it with the fuel pump it struggles pretty bad, runs a little rough and definitely will stall over time. Without the fuel pump you can see how it runs so I’m near positive it’s just pushing too much fuel and flooding the carb. I’m going to adjust the float fairly aggressively and see if that might help. Right now it’s within spec, but I wonder if I need to just go a little more aggressive.

More data! Definitely running way too rich. Fuel in the crankcase I think, the oil level is higher than I remember it being and smells a little bit like fuel… But the big clue is the plug, pictured below. Black as night. I took a video of the fuel pump off the carb. The quad runs really well in this way, so I think Mech you are right that something isn’t seating. QUESTION; does that fuel pump look like it’s pumping correctly? From descriptions I’ve seen it seems fine but I want to be sure. (I’m adding a YouTube link for the video because it’s larger than the attachment limit) vidoe here: It’s amazing to me this could be traveling across 4 different carbs.. but here we are! Is there anything else I can check on this? I took the bowl off the two carbs previously and both floats were .97 and .98. Unless I’m measuring wrong, the spec is .9 to 1.0in. I would assume thisnis ‘fine’ but I could adjust it more aggressively.

So your suggestion is to change float needles or adjust the float? It just seems impossible that over four different Quadrunner 250 carbs I would have all four not be able to hold fuel pressure. Doesn’t it? Hell even the rebuilt OEM carb isn’t. I haven’t been able to locate a clear instruction on how to adjust the float on these carbs as yet. I debated trying to restrict the fuel pump somehow to test but I haven’t figured that was a worthwhile test long term.