Couple of VERY VERY easy exhaust questions (for any 2 stroke)

[sorny]

Here's some REALLY newbie questions that I just don't know and have been meaning to find out since I got my YZ back in May. Ok, since I got my YZ I've noticed that for one, I don't have the 2 rubber exhaust ring "gaskets" that go on the engine-end of the head pipe. I know this is causing spooge to leak down, but besides that is it a problem for powerloss or anything? Does that needed to be sealed up?

Ok, then number two, since I've had the bike, the area where the head pipe and the muffler's pipe meet is just pushed together. So that drips spooge too, although very little, it gets on my nerves. Someone told me to get a short (1.5-2") rubber hose, slip over both ends and use 2 screw clamps (like on radiator hoses) to hold it on place. Would that work? What does it look like from the factory, I can't even imagine what would hold them together. This is my first bike, obviously, and none of my friends have bikes (all quads) so I can't look at others and see.

 

[gwcrim]

Not sure about the o-rings, but for 0.50 cents or so, I'd sure run them.

As for the joint of the two parts, that is a great fix. I don't use hose clamps. I use zip ties.

 

[sorny]

Well, the onyl reason I didn't get the o-rings is because when I went to the local (and only shop within 60 miles) they didn't have them. I found them online but at like $5/ea so I just put it off. I was afraid at first that the rubber hose covering the joint would melt but I've noticed that I can touch the headpipe on my bike just minutes after shutting it down and its barely warm, so I guess 2 stroke small displacement motors aren't like automobile engines I'm used to and stay rubber-melting warm for and hour after being ran.

Edit:
Found the exhaust joint (if I wanted to go factory looking instead of the rubber hose) on bikebandit.com but its $22! Also, here's where I saw the O-rings, I assume that's EACH:

http://houseofmotorcycles.bikebandi...&model_dept_id=392403&model_dept_name=YZ250L1

 

[Lorin]

Some people use hi-temp silicone caulking at the head pipe \ cylinder junction. I've even used yamalube with some success. I've also used a piece of inner tube at the pipe \ silencer junction. Both these solutions were used on previous bikes with moderate success. That said, I much prefer using the o-rings, and rubber clamp that come on the bike stock. I think I was able to price the rubber clamp at $12 locally.

 

[sorny]

Oh yeah, I forgot that my bike came with an FMF pipe that was severely dented (didn't even try to run the bike with it) and the guy had just used silicon stuff to seal up the fmf and the stock muffler pipe. Some of it still is on the stock muffler pipe when I put a replacement head pipe on when I brought it home.

 

[sodflyer]

I just bought a "TM Designworks No Leak Exhaust Collar" from RMATV online and yeah it was 35.00 but with my stock coupler it was spooging all over my swing arm...now no more spooge :) well worth it plus it looks better than the stock unit. I'd say get the o-rings for the pipe... I have them and no spooge there either. My buddy's bike does not have them and it's a mess everywhere. Jeff.

 

[sorny]

Oh yeah, I saw those collars in the RMATV catalog and wondered if they'd work or not. I'm super tight with cash right now so I'll probably just put a couple of bucks in the rubber hose. My bike looks rough anyways, so a nice exhaust collar isn't going to help it out ;) (I need all new plastic). I've been wanting to clean up the motor and swingarm area, but when you know you're just going to get it nasty again it's kinda pointless. Guess I need to see if I can get those o-rings locally again, they might have just been out of stock.

 

[sorny]

Well, called on the o-rings, now they can order them... $4.84/each which is about what it costs at the website I posted earlier.

 

[sorny]

Oh, while I'm asking you guys stupid questions, lemme ask one about my rear wheel. It looks like it has a bolt sticking thru with a nut on it, holding it in place. What the hell is that about? I dunno if a spoke is missing or what. It really looks like they took the tire off , drilled a hole and put a bolt thru and put a nut on the end of it. Looks like a 2nd valve stem from far off.

 

[CaptainObvious]

Rather then trying to stop the spooge from leaking out of the exhaust system, why not just stop the engine from making spooge in the first place.

If you are leaking spooge from every junction on the bike, it’s a clear indication that the engine is jetted entirely too rich. With a proper jetting you will never need a seal between the pipe and silencer (it’s an expansion joint), the engine will have much great throttle response, you will (almost) never foul a spark plug and your power valves will always function properly.

The "nut" on the rear wheel is the rim lock. It keeps the tire from spinning on the rim.

 

[sorny]

AH, a rim lock, like Jeeps and 4wd trucks using bead locks. Glad to know it wasn't some redneck fix. And about the spooge, I thought a little was normal. It must not be too bad because I've had the bike since May and although I haven't ridden it every single weekend since, I haven't fouled a plug yet and I lug it a lot since I'm a beginner. But anyways, there is like 3 drips on my swing arm and maybe a 1" wide "puddle" around the headpipe/engine. Not like its coating the bike. Just enough to know its there when you look for it.

 

[uts]

Technically you may be loosing some back pressure and therefore power from the lack of the seal at the engine flange. Saying that though my cr used to have the same problem and when I sealed it up I didn't notice any difference in the power.
As for the jetting, if your bike runs well through all the rpm range I wouldn't bother. I watched a mate who is not experienced (like me)at jetting try to tune his bike that was obviously a bit rich(spooging) but ran well. It was a nightmare and he ended up putting the original jets back in. But there are a lot of experienced jetters on this forum who would gladly talk you through it, I am sure.

 

[fng2moto]

If you use a .50 cent o-ring it'll melt in about 2 minutes. Those o-rings are $5 for a reason, they don't melt. Then again I don't recall them being $5 here in San Diego. More like $2.50.

As far as the joint goes, on my kids KX80 I put high temp exhaust sealant -Half Way- up the male end of the silencer and slid it in the pipe. Or maybe for some vice versa. Nice and pretty and it doesn't leak.

My 2 cents :cool:

 

[sorny]

uts: I feel that the bike is running about as good as it gets and like you said, I'm afraid that jetting it will only make it worse if I do it myself and I'll end up going back to stock :) After all this time, on one plug, I'm thinking its not completely aweful, but just be fine tuned a bit. But it's very smooth in the powerband, no flat spots(well, as "smooth" as a 2 stroke can be). Power comes on like crazy at any RPM w/o hesitation. Of course if I had tons of hours ont he bike I'd probably be more sensitive and could notice the fine tuning stuff.

fng2moto:

The only reason I wouldn't use the sealant stuff between the head pipe and the silencer pipe is because the flange on the head pipe that bolts it to the frame is broken off. So it wiggles around a little bit. The other one is there so it holds in place pretty good, but moves fractions of an inch at the most so I think the sealantwould just be pulled and pushed on too much.