Partzilla Live Q&A with John Talley – March 18, 2022

John Talley brings you another edition of Partzilla Live Q&A, answering your motorcycle and ATV repair questions.

Motorcycle repair for several makes and models came up during this edition. Check out some excerpts from Partzilla’s latest live Q&A session below, and tune into our YouTube and Facebook channels every Friday at 3pm Eastern for the next edition. 

Partzilla Live Q&A 03-18-22

Partzilla Live Q&A Highlights – Motorcycle Repair

Honda Motorcycle Repair

Your 2018 Honda Grom series was great, but why are fender eliminator kits so expensive? Even the ones that only include a piece of sheet metal and some basic hardware.

John Talley: I would imagine it’s just the cost of producing them in small numbers, because not everybody orders a fender eliminator kit. Yeah, it’s a case of “we’ve got what you want and you’re going to pay for it.” When I did the Grom fender, we saw it’s ridiculous. It looked like somebody mounted a skateboard on the back of it. … The one I used worked out pretty well, but it was just a few pieces of metal and it was kind of expensive.  

I have a 2005 Honda VTX 1800 that runs well, but it bogs down and eventually dies. It restarts and runs for about 15 minutes, then dies again. Could this be the fuel pump?

John Talley: Probably not. What you’re going to run into is, there’s a line coming off the tank that is of course a vent line for the tank. And if it’s stopped up … what you’re describing is a vacuum lock inside the tank, and it’s letting the engine run for a while, and then shutting it down, because it’s building up too much of a vacuum. I’ve actually seen it build up enough of a vacuum to where it collapsed the tank of a 1300 Yamaha. … Check your fuel tank vent line, because I bet it’s clogged.

Suzuki Motorcycle Repair

I have a GSXR1000 that’s struggling at idling at lower RPMs, at anything below 2000. Above that, it’s silky smooth. I cleaned the throttle bodies, injectors and the fuel tank pump and changed the strainer, but the problem still persists.  The fuel pressure gauge is erratically going up and down. Is the fuel pump the problem? 

John Talley: Typically, you’re correct. Most times a faulty fuel pump will let it idle, but it doesn’t want to deliver all the juice once it’s really under demand. Just at the lower RPMS? I’m beginning to think it’s not the fuel pump. I wonder if it’s your throttle position sensor. That would be what I would look at. If it got bumped, even a tad while you were working on it or you replaced it and it didn’t calibrate it again, it’s getting a false zero and probably trying to bring it down even further. And that could cause it to not want to run at a low RPM. So I would get away from the fuel delivery system and take a peek at the throttle position sensor and see if it’s measuring in range. Hook an OHM meter to it and it’ll probably have three pins. One’s got up to 5 volts of power on it and the other is basically a potentiometer, and you’ll want to run the throttle plates through their complete movement and do a high and low reading just using resistance. See what you end up with and compare it to the manual. 

Yamaha Motorcycle Repair

Does the stator on my 2005 Yamaha R1 have a certain position it needs to be inserted to be lined up with the cover? The timing is good, but the spark is weak and doesn’t spark every time. 

John Talley: Your stator should have three bolts on the inside and it could only be mounted one way. I don’t think they’re symmetrical, so I think you can only go in one way. Plus, if you have it rotated one way or the other, then your wiring wouldn’t line up correctly for it to run out the side of the cover itself. As for the weak spark, I wonder if it’s your pickup coil because that’s probably part of that harness as well. If memory serves, the pickup coil is the one thing that’s in charge of your timing. That’s what keeps up with the crankshaft and tells you when it’s in position to fire. So take a look at that. 

Want to see more live repair questions answered? See all of Partzilla’s past Live Q&A sessions here.  



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