Ahhh the TPI bikes KTM came out with in 2018. I bought the first 2018, 19 and 2020 bikes that came into Arizona. And after tearing the 2018's top end down, after the first 50 break in miles, it was apparent there were some big wear problems going on.
Wear marks in the cylinder and piston to be exact. And after figuring out how the whole TPI system worked, it was obvious why. Even though the 2020 Bikes have a lot of the issues fixed that the 18-19 bikes had, they haven't fixed the pre mature wear problem.
Long story short, the 20's are better, but the 2018,19 and 20 TPI 250's and 300's, are AWESOME PILES OF CRAP
So the purpose of this page, is get you what you need, to fix the crap, and just be left with awesome.
So the bikes have 2 MAIN problems. One is, they start and run for a few seconds with no oil getting to the upper part of the cylinder. And two is, the stock fuel pump and in tank filter are junk quality and will fail at any time.
Within the first 100 miles of owning the 2020 TPI bike, here is all the problems that occurred. You can decide what issues may be important for you to fix, so that you don't find yourself stranded.
Above are the 2 shots of the cylinder wall rubbing in the first 5 minutes of the bike running. The bike was started by the dealer and then shut off. I took it home and rode it around for a bit, so it totalled about 5 minutes of run time. Then the top end was pulled off and these rub marks were the result. If there was instant lube going on, like on a carb bike, then you wouldn't see these rub marks all around the cylinder.
And if you wonder how this will affect you, then you may very well end up where most tpi owners are. This is wondering why your top end wore out in 60 hours instead of lasting about 200 hours like your carb bike did.
It's all the lack of lubrication during startup, and the lack of lube even while running. The bikes start on just fuel alone, until the oil can get through the reed assembly and through the bottom end and then through the transfer ports. Then, it will finally get onto the upper cylinder walls. This is problem number 1, and it's the most predominant problem.
The easy way to fix this, is to just add one ounce of oil to each gallon of gas in the tank. That makes sure there is always lube there, plus one ounce takes the 80:1 fuel to oil ratio of the tpi bike, and makes it the same as the 60: 1 ratio, that the KTM service manual calls for, for the carb bikes.
The only issue with adding the oil to the stock bike, is the very slightly thicker fuel / oil mix, struggles a bit to get though the dinky size stock fuel filter, which may cause for erratic bottom end performance. You can see how small the cone shaped stock filter is on the right side.
We have an easy fix for it though. You can see our large area, quick disconnect fuel filter, and it's large filtering element on the left. Our element is 6 times larger than the stock one, and also filters better, being a 10 micron screen vs the stock 20 micron screen. So it filters better but also has the area so that the slightly thicker fuel/ oil mix, doesn't slow down the flow.
This is how it allows you to add one ounce of oil, to each gallon of fuel in the tank, and solve all your lube and wear issues. Then when it takes a few seconds for the oil injected oil to catch up, who cares.
You can see above of how it fits into the plastic side of the quick disconnect. You also see our high flow 90 degree tank fitting, so the bike doesn't lean up after a few seconds of wide open running.
So I quickly fixed the problem with the new filter and added an ounce of oil to each gallon of fuel in the tank. Cheerfully I headed off into the desert, to break in the bike with confidence, knowing that it had all the lubrication it needed.
This leads us to problem number 2. At exactly 10 miles the bike started to act sputtery. I thought, "oh crap". Then it ran better for a few seconds. Then it died. It started back up and ran sputtery. I turned around and prayed. Then it quit. I had to push it to the main road and flag down a full on hillbilly with no shirt and a broken 6 pack rack on an old quad, to give me a ride back to the van. The whole time back he told me how if you cook javelina just right, it tastes like rattlesnake. Unfortunately, I'm not making that up.
The problem ended up being, that the stock, cheap, plastic shelled inside the gas tank filter, as shown cut apart on the bottom here, split. Because the stock filters have plastic shells, or outsides, they have a hard time handling the 52 psi within the fuel system. When they split from the pressure, your fuel pressure goes straight down. Now no pressure gets to the injector, o fuel gets to the engine, and you get to ride home on a broken 6 pack rack getting javelina cooking tips.
I can tell you, you don't want that ride home from Jethro, on his old quad. That's why we made the billet in tank filter, that you see above it. It has a husing that ofcourse can't fail, but you can also see, the much larger fuel filter as well. And our filter is 10 microns, instead of the stock 40 micron filter. This means that ours filters out power robbing particles, that are 4 times smaller, than the stock one can.
Here is the stock filter vs ours. You can see the size, and therefore filtering area difference. Plus it can't fail
So at this point it should have been good. 2 big issues fixed in 10 miles. It was good until 80 miles hit and the odd running started all over again. Fuel pressure was checked and it was 40 psi. It should be 50 - 52 psi.
This time the stock fuel pump crapped out. I have to admit that I was as frustrated as any customer here would be. I just spent $12,800 on a motorcycle and it's failed on 3 big accounts in less than 100 miles.
Luckily, we already had the good stuff here, because the stock pumps are just junk and we had already sourced really good ones from Taiwan. So, the pump was now changed and all was good.
Now that all the main issues were fixed, the bike was running really good and at least it was protected as far as lubrication and parts failing were concerned. So now we could start really testing.
One of the first things we did was put an air / fuel meter on the bike to see it's running habits.
And it became quicly apparent, that when the bike was held wide open for 3 or more seconds, that it would start to lean out. This ended up being casued but the small restrictive passages in the stock 90 degree fuel tank fitting. This is the same fitting as the 4 strokes have, so we already knew it was a weak link. You can see the small passages in the stock one on the left, and the large passages in our high flow one on the right.
And the new fitting fixed that leaning out part. Then we ran it all together on the dyno. The new fuel pump and in tank filter, the bigger outside filter and the new 90. Then we added one ounce of 2 stroke oil ( the same oil we had in the oil tank ) to each gallon of gas in the gas tank, and ran a few times more on the dyno.
And as you can see from the dyno runs below, the bike really seemed to like all this. The stock runs were the blue line and the new ones averaged out to be the orange line. It was a bit better EVERYWHERE.
So more reliability, less wear and more power. Can't beat that
Then we coupled it all together in one big bundle kit, which gives you a nice savings