701 sm

[cg_ops]

So glad I don't have to deal with my 701 after revisiting this thread

The 890 has been such an awesome step up in hooliganess, nimbleness, and enjoyable...ness.

I do miss the 701's propensity to raise its front end like a preying mantis every time something spooks it. The 890 may be a lot more powerful but the geometry of a sumo is MUCH more conducive to whoolies

[JesasaurusRex]

Originally Posted by cg_ops

So glad I don't have to deal with my 701 after revisiting this thread

The 890 has been such an awesome step up in hooliganess, nimbleness, and enjoyable...ness.

I do miss the 701's propensity to raise its front end like a preying mantis every time something spooks it. The 890 may be a lot more powerful but the geometry of a sumo is MUCH more conducive to whoolies

haha glad you like the new bike

i've flogged this thing for 10k miles so i'm really not too upset if it's a head gasket. Also bang it off the limiter more than i should lol . Finally stiched up the oil leak on the tx300i so I still have something to ride


So i got my new pressure tester and was able to complete a pressure test with the snapon adapter and without the faulty test cap and it holds pressure fine. Maybe dropped .025 bar in 30 mins time, i think that's probably acceptable?
Unfortunately i still don't know a good way to test the OEM cap. You can't go through the cap obviously because it would just vent back into the pump, so one would have to either splice the radiator hose or go through the sensor port on the radiator. Both of which would take a little bit of fab that i'm not interested in. So i'm going to throw the new cap i purchased on the bike and ride it around and see what happens. If it's fixed, great. If not i'll pull the head.

Keep you guys posted

[RichieRich]

Good information, I need one of these in my life!

[JesasaurusRex]

Originally Posted by RichieRich

Good information, I need one of these in my life!

sell you one

[JesasaurusRex]

Well got started, time to order parts i suppose

[paul cbr]

Originally Posted by JesasaurusRex

Well got started, time to order parts i suppose

So it wasn’t the cap?

[JesasaurusRex]

Originally Posted by paul cbr

So it wasn’t the cap?

Not unless the new one was bad too. Doubt it, but still haven't found a good way to test it unfortunately.

So far not really that much of a chore, hope it stays that way.

[JesasaurusRex]

So it's been about a month since I pulled the motor, holidays, work, family and other hobbies/bikes has consumed my free time. Got around to pulling the head today so about half way done. The really odd thing is I did a leak down test before pulling the head and I had 10% leak. After staring at the gauge for what must have been 30 seconds I decided i wanted a picture so i started searching for my phone and somehow in that time frame the thing sealed up and I was at 2% leak. Pretty positive the engine didn't rotate any and all the valves were closed. I took the air off and pulled the cam before retesting to be absolutely sure, but I was unable to recreate what had happened and it read 2% steady the entire time. Once again, positive the valves were closed. There may be some weird thing going on with these motors and head gaskets, which would explain the pushing water under load but not at idle thing. Very odd, but saw it with my own eyes. Anyways, here's a few pictures, maybe someone that knows what they're looking at better than me can shed some light if they see anything odd. Nothing jumped out at me really, piston seems a bit dark but the lighting isn't the best in my garage? 10k miles so i donno how it's supposed to look. Unfortunately I don't have a machinists straight edge to see how straight the block/head decks are. Rule of thumb as taught to me has always been .001" per cylinder on a bank, but it only being 1 cylinder I don't even think i have a .001 feeler guage. Gonna clean up the decks tomorrow and probably slap it back together and see what happens. Fingers crossed.

Top of piston/block deck



Head side of gasket


Block side of gasket


Bottom of cylinder head


Leak down