thoughts on the 300R kit

[ATCT]

OK, so, thanks to some members here on the forum, I just realized I have a 300R kit on an '83 R project that I was about to sell. So now I'm not sure what to do. Not sure if I should just build up this '83 (not sure how much sense it would make to have a 2nd almost identical R when I could use the money from selling this stuff off) or put the kit on my all-original '84 R (I probably wouldn't do it right away, as I really want to start riding--stupid AZ title is holding me up at the moment).

I guess the question is, is having the 300R kit really worth it? Obviously more power, but if I'm not really racing it, etc.... I think you get what I'm saying.

I think some of my reticence is, I've never rebuilt a 2-stroke engine. Worked on car engines before, but it's obviously different. For instance, I'd need to remove the piston from the engine. Not sure how difficult it is on these engines....

I'm leaning towards just keeping the kit for now (uh, I think?).

Thanks for the help. Appreciate it.

[yaegerb]

Yes, the 300R kit is worth it.

Nice, rare piece and is an excellent power add throughout the entire RPM range on the 2nd gens. Part the whole bike, keep the motor and switch the cylinder over to your OEM bike....or keep this R and make a sleeper.

[ATCT]

Yes, the 300R kit is worth it.

Nice, rare piece and is an excellent power add throughout the entire RPM range on the 2nd gens. Part the whole bike, keep the motor and switch the cylinder over to your OEM bike

Thanks. I'm definitely leaning towards this way. Maybe I can get some help from someone when I decide to put the kit on my '84 so I don't screw it up.

[yaegerb]

take a look at stroberts22 300R build. Nice write up and lots of good pictures.

[christph]

Definitely keep the 300 kit--they are pretty rare. I'm like you, I have one but I'm saving it for a future project. Don't be afraid of rebuilding a two stroke, they are much easier than four strokes. The only issue with the 300 kit are replacement pistons. There are basically two options here, assuming you can't find NOS. One, send your used piston to Wossner for a custom piston. Unfortunately the minimum order is 4. Or, there is a guy that will alter your jug and so you can use a piston from another machine. I believe he advertises on ebay.

[barnett468]

I guess the question is, is having the 300R kit really worth it? Obviously more power, but if I'm not really racing it, etc.... I think you get what I'm saying.

If your 84 is stock or close to it and you are completely satisfied with the power, there is absolutely no point in installing the kit and you could sell it and put the money to use elsewhere.

If your 84 is near stock and would like more bottom end and mid range power, the kit will make a noticeable difference IF it has not been ported to rev to 10 zillion rpm like some of them have been and the easiest way to find out if it has is to simply install it.



I think some of my reticence is, I've never rebuilt a 2-stroke engine. Worked on car engines before, but it's obviously different. For instance, I'd need to remove the piston from the engine. Not sure how difficult it is on these engines....

If you have ever removed and replaced even just the intake manifold on a car engine before, you could EASILY do the top end on a 2 stroke . . it is in fact easier than building an erector set . . The hardest part is getting the wrenches out of your tool box.

As was mentioned, there are build threads here to check out, but there are also free factory online manuals in the link below that are extremely helpful.

1. remove gas tank and exhaust pipe.

2. drain carb via drain screw or remove it and dump it upside down.

3. with the carb, pipe, and spark plug removed, remove the cylinder head nuts and pry it gently to remove it.

4. remove the 4 nuts on the bottom of the cylinder then gently try to pry it up and if it doesn't move, whack it back and forth with lite/moderate force in the front the rear with a rubber mallet . . the base gasket sometimes sticks and this "should" break it loose.

5. stuff a clean rag or paper towels into the engine arund the crank and rod to keep debris out.

6. use a tiny screw driver or dental pick etc ans stick it in the notch in the side of the piston then put your finger over the hole to prevent the clip from flying and gently pry it out.

7. after the clip is out simply push the piston pin out from the opposite side with a screwdriver far enough to pull it straight up aff the rod . . there will be a needle bearing in the rod which typically gets replaced.

8. inspect and measure parts for wear and damage.

9. put a little 2 stroke oil on the bearing and pin for installation.

FREE MANUAL

http://www.oscarmayer.net/atc/manuals/


PISTON CLIP R & R

You can see the notch in the piston that you need to pry from . . some piston clips [circlips] like the ones shown in the package below, have the end of them bent upward and you can simply grab that end and rotate/bend it towards the side of the circlip it is connected to . . if done properly which is easy to do, this will compress the circlip enough to remove enough of it from the groove that it can be pulled out . . you dont want to rotate/bend it a lot if you plan to reuse it because this will distort it.

To reinstall a circlip, simply oil the hole lightly then place the circlip over the pin hole then push one end of the circlip into the hole around 1/8" then place your finger over that area then slowly go around the circlip pushing it into the hole . . if the end of the circlip is bent up, you can grab it with needle nose pliers and bend it inward slightly after you get it started and go around and push it in . . make sure it is fully in the groove and not loose in the grove . . installing these clips is the most difficult part of the project and might take 1 minute per side.

....................http://g01.a.alicdn.com/kf/HTB13PzoKVXXXXakXXXXq6xXFXXXN/motorcycle-font-b-piston-b-font-kit-with-font-b-piston-b-font-font-b-ring.jpg
.

[ATCT]

Thanks for the info!

I'm guessing after riding the stock bike a while, I'll end up wanting some more power. It would seem foolish to sell it prior to figuring this out. Maybe I'll start pulling the 300 head this week to see how it looks and if anything has been done to it.

[barnett468]

Thanks for the info!

I'm guessing after riding the stock bike a while, I'll end up wanting some more power. It would seem foolish to sell it prior to figuring this out. Maybe I'll start pulling the 300 heat this week to see how it looks and if anything has been done to it.

Yes, you can definitely sell it anytime if you need or sell your stocker if you use the kit and need cash, but if you're not broke, I would keep it even if I didn't use it.
.

[cr480r]

Does the 300 run now?

[ATCT]

I was told it ran strong prior to partial disassembly.

[Dirtweed]

Keep it, but if you do decide to sell it let me know. Been thinking of looking for one for my 82R.

[onformula1]

Here is a good way to go if you need a piston-

http://www.racerstoystore.com/holiat300big.html