what is involved in boring a motor

[tc862011]

and how would you use a zip tie to adjust valves?

[7981GS]

Ride it, add some oil and ride it some more until the snow flies.

Eric

[tc862011]

thats my plan lol, anyone out there riding a 550 converted to a 650, whats the pull like compared to the 550, what would i be looking at for performance gains if and when i do the conversion

[tc862011]

just found an 82 650g motor for a little over 300 and thats with shipping included, if that would work all i would have to do is get the carbs, new gaskets, new rings, new valve seals and so muscle and tedious careful work, if that would work on my bike. meaning taking the the top end off and doing a surgical transplant onto my 550

[7981GS]

just found an 82 650g motor for a little over 300 and thats with shipping included, if that would work all i would have to do is get the carbs, new gaskets, new rings, new valve seals and so muscle and tedious careful work, if that would work on my bike. meaning taking the the top end off and doing a surgical transplant onto my 550

Sounds like a great winter project.
And a new fun bike in the spring!!!

Eric

[tc862011]

yea thats what i am thinking

[lonerider00]

and how would you use a zip tie to adjust valves?

I'm curious about that too...

[lonerider00]

tc sounds like you have a good plan. When you do it, make sure you measure EVERYTHING, be meticulous and double check all of your clearances, do a proper break-in, and you'll be well on your way (my question would be to someone who's done the conversion before is if any modification/machining needs to be done to the cases in order for them to accept the 650 cylinders. When I did a similar conversion on a jet ski years ago, I needed to grind out the cases because the barrels wouldn't fit as a direct swap [probably not a problem with the way these engines are designed, but it's worth asking]).

[tc862011]

i have been reading the posts about doing it and they say you have to do minimal grinding to the flashing on the cast inside where the cylinders meet so that it mates together right but by looking at it it is very small amount of grinding. and i will start this as soon as it gets to cold to ride here in maine, and i will take my time and do everything right the first time, i guess the rebuild on this motor was practice so i dont make the newb mistake when upgrading the engine. i am really looking forward to this and will take it one step at a time and if something doesnt work then i will take my time instead of rush it. i refuse to let frustartion get to me this time. i want my 550 to be a heck of a sleeper bike while making it a bunch of fun lol.

[tc862011]

now with the breaking period, i have read that doinga slow breaking as per the factory suggests is bad, what i have been reading is to ride it with the rpms stretched out a little bit in each gear and to keep the compression up in the accel and decel to male the rings break in evenly is this correct or is there a better way to do the breakin

[Nessism]

when i pulled the cylinders to change out the bad base gasket i had asked on here if i had to rering and rehone the cylinder and was told no, so thats what i went with.

Just so there are no misunderstandings here: if you replaced the rings and honed the cylinders, but had a leak thus forcing a second tear down, there is no need to rehone and replace the rings a second time. Just be careful when installing the rings as normal and always use OEM gaskets.

[tc862011]

thats what i was told when i had to replace the base gasket so thats what i did

[Big T]

now with the breaking period, i have read that doinga slow breaking as per the factory suggests is bad, what i have been reading is to ride it with the rpms stretched out a little bit in each gear and to keep the compression up in the accel and decel to male the rings break in evenly is this correct or is there a better way to do the breakin

That's correct - ride it at 4-7k, varying the throttle and rpm -speed up ,slow down -after 200 miles or so, you can rev it to redline on occasion

[Steve]

And, I'm confused- in post #7 you state the valve stem seals were replaced. Did you replace them?

He answered that in post #7.

..., i had replaced the valve seals and then i ended up having to get a new head ... i found a good usable head on ebay and switched it but completly forgot about the valve seals on that.

.

[Nessism]

That's correct - ride it at 4-7k, varying the throttle and rpm -speed up ,slow down -after 200 miles or so, you can rev it to redline on occasion

Not trying to start something here but there are various philosophies about breaking-in an engine. The OEM manufacturers typically suggest an easy break-in, but the racer guys advocate using lots of throttle early on in the break-in cycle. I believe in using a good bit of throttle is good, and the OEM technique is partly based on product liability, as they don't want new riders going crazy with the throttle and crashing.