The r3v motorcycle thread

[Northern]

My friend's GPz is sadly not in the best shape, we resealed the forks and cleaned the carbs but it's still a pain to start and keep idling while it warms up. We're probably tearing into the carbs again with a rebuild kit and doing some engine refresh over the winter. Also maybe trying to figure out the whole anti-dive system and seeing if it's actually working.

Sounds like a cheap bike is turning expensive

Definitely going to sink $500 into this bike to get it driveable and not a dumpster fire, but still ends up being pretty cheap.

I bought a full F4i trans last night for $80. I couldn't see 2nd gear dogs from the photos, but every other set of dogs looked pristine so I'm hoping it works out. Some gears are common between the two, so I'm really hoping the main/countershaft still have the same spacing.

[tim88325is]

My GPZ550 carbs were kind of a mess, the needles didn't match. I ended up getting a Dynojet kit and a rebuild kit to just replace everything and rejet to the aftermarket pipe that was on the bike. These small bike jets are so tiny, hard to tell if they are clean or not. The new jetting is fairly rich on the needle with a smaller than recommended main jet since the airbox is stock, starts and idles great with excellent throttle response and revs freely too.


I just replaced the seals and used new fluid, bike seems to handle as well as anything from that era. I added 8psi to the front forks too per manual.

[Northern]

My buddy has two snapped off/ seized jets in his GPz, can't remember which. We didn't want to do any more damage at the time, but he's ordering a jet kit for this winter. Also his float bowl drains are all sorts of messed up, so I don't know what his plans are there.


The F4i gear set showed up. It looks pretty good and has the same spacing as the F4 so it'll fit. Edit: Apparently it doesn't have the same spacing...
I'm going to pull it apart to clean/oil it before I throw it all back together, also will check the shift forks for any kind of bends/wear.

Pretty pumped to put it back in the bike and not have bike parts all over the place, then it might end up in the shed before snow falls.

[LateFan]

Hasty Flaming Buffalo

[LateFan]

At the Peterson Museum...

[LateFan]

OK, you knowledgable bike guys, explain this to me - why is the seat so damn high? is it current style, is it front-rear weight balance, is it handling...? The rider seems to be really high and farther forward. Don't you want your center of gravity as low as possible?

[econti]

Being forwards makes them easier to slide (weight on the front wheel to keep it gripping as much as possible) and height makes it easier to flick into corners. At least that's what I find.

[tim88325is]

I think that model is meant to have an upright riding position. Not a sports bike crouch or a cruiser recline, see the new Ducati Scrambler line or any "standard" Japanese motorcycle from the 70s, CB750, CB550, etc.

[varg]

Don't you want your center of gravity as low as possible?

It's more complex than that. It makes little difference at speed in a straight line where stability depends on suspension/steering geometry and its interaction with the gyroscopic effects, and going slowly it just changes the technique required. Bikes with a very high center of gravity like supermotos are incredible at cornering, it just requires a different technique to do so than on a supersport.

[LateFan]

Thanks. It just seems like you'd have to throw your weight side to side a lot more to lean it over. And it just looks a bit goofy to me.

[varg]

Nah, wouldn't be that bad. The weight of it (527lbs wet per Indian's website) would make more of a difference than how tall it is. It is actually very similar in specs to my ZRX, which is not at all effortful to transition and corner with. Riding position on the ZRX is a little more feet forward and leaned forward, seat height (with flipped eccentrics like mine) is almost the same.

Man do I miss riding my bike, but the carburetors have been giving me such a fit. I get busy and can't ride it for a little while and if I forget to run it a couple of times per week I wind up having to pull them off and clean them because they gum up so fast. Swapped carbs for a set that do not have a broken casting like the ones that came on my bike and I just can't get it to run right.The 'new' carbs came with drilled slides and non-stock needles which might be contributing to the transition issues so I might have to put my stock slides back. One of them has a pinhole sealed with rtv which is what prompted me to swap them in the first place. I had it running nicely at one point with the shimmed stock needles and larger main jets so I want to just get back to that point. It needs a valve adjustment too and it uses those damn fiddly little shims

[Northern]

What do you run for fuel? Do you think it's ethanol that's gumming up the carbs? Any chance it's debris in the tank?

[varg]

I'm fairly certain it's the shitty Ewhatever fuel I have no choice but to purchase here

I've never actually tested the ethanol content but it certainly behaves like it's more than 10% by how fast it goes bad sitting in my garage. No chance it's debris from the tank, I have a fuel filter inline and never find anything other than the white crud and varnish in the bowls. The bike runs on regular 87 and there is no evidence the 91 or 93 in these parts has less ethanol so I just buy 87.

[Northern]

Ah I see, my local gas has ethanol in 87/89 but 91 is "ethanol free" so I just run 91 in bikes/snowblower/etc and haven't had a problem.

[DatUtahGuy]

Here is my dirty girl, I ride her hard and put her away wet every time :)