Vintage Dirt Bike Q & A

Picked up a tank off ebay... I remember why I quit working on old stuff now. The screw that holds the petcock on the tank on my mr175 is completely rusty, screwdriver slots are gone and there is nothing to grip. What's the best way to get it out?

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

If it were mine, I'd heat the screw end cherry-red, let it cool, then remove it with Vice-Grips I did this recently on a snapped-off MR175 cylinder stud, it worked great. The screw will expand and then shrink, breaking the rust bond. If you don't completely break the bond on your screw, it's likely the threaded tank insert will rip itself out of the tank.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

I don't think I can get a vice grip or any sort of pliers into that space. I've had old bikes before but never seen anything with a screw that is inside the petcock. Maybe try heating it up and then using a stuck screw remover kit...

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

Sorry, I forgot how these petcocks were arranged... assuming the '75-'76 type with the single screw above the screen, I'd drill off the screw head, the petcock should slide right off, then heat/turn the remaining screw shaft as in my earlier E-mail.

If the petcock needs to be replaced, I think this may work:

http://www.ebay.com/itm/Honda-CL70-SL70-XL70-XL75-XR75-MT125-MR175-MT250-Fuel-Cock-Petcock-Valve-Gas-Tap-/361009516959?pt=Motorcycles_Parts_Accessories&hash=item540dd8119f&vxp=mtr

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Sweet. Thanks for the advice.

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

I randomly sprayed the screw with liquid wrench and used a hand impact to remove it. Petcock is free!

Now, does anyone make gaskets for the darn thing? They might be usable but I'd rather get something new if I can.

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

I believe all the petcock seals / O-rings are still available from Honda.

http://www.westernhillshondayamaha.com/OEMpartfinder.htm#/Honda/MR175_A__MOTORCYCLE%2c_JPN%2c_VIN%23_MR175-1000001_TO_MR175-1008522/FUEL_TANK_%2b_FUEL_VALVE/MR175-JPN-A/2Y133732F13373211C

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Oh sweet. I did a google search but found a lot of ebay junk. I didn't even think to look at OEM; thought for sure they wouldn't offer it anymore. Thanks. Just have to get the tank cleaned & coated now. Maybe put some brakes on it. The current brakes have all the friction of squirrel fur.

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

There are a couple of replacement petcocks on ebay for the mr175 that work pretty well. You can usually get one for $10 - $20. Just make sure you get one that looks like yours. I think mine came from thailand.

So I am finally getting around to reassembling the cleaned petcock with new parts, but I need to replace the screw. It's quite rusty and I could probably refurb and reuse it but I'd rather not. I don't think it was an item on the parts fiche so where do I get one? Can I just use something from the hardware store?

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

The screw is a 40mm long M6x1.0 panhead, Honda P/N 93500-06040-0A. If you can find a stainless M6 screw at the hardware store in a length that works and with a head that fits the petcock hole, that would be great, but the Honda screw will definitely fit and last quite a while before it rusts again - so it's up to you.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

I am just not sure the screwdriver slots are in good enough shape to risk it. I will look for a replacement but may have to reuse it.

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF

I meant a NEW Honda 93500-06040-0A screw from your local dealer, probably $1 with tax (they may have something identical in stock, maybe even in stainless). I would never recommend reusing any bolt that rusted in place, especially one that's still available from Honda or any decent hardware store.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Oh, duh! I misunderstood.

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1974 Honda MR175, 1974 Honda MT250, 2003 Honda CRF150, 2003 Suzuki DRZ125, 2005 KTM 250 SXF