New to RZs

[This old RZ]

One thing I've noticed and no one can convince me otherwise. I'll probably catch crap for this,but 4 strokes generally are FAR more reliable. You can practiclly drag a old 4 stroke out of a barn where it has sat for 20 years,and I't will start and run and drive it for years..But the 2-strokes,almost always require a teardown or rebuild.
The saying ' THE CANDLE THAT BURNS TWICE AS BRIGHT,BURNS TWICE AS FAST" really holds true,to 2-strokes. I have friends who have 60-80,000 miles on original 4-stroke motors and 1 friend now has over 120,000 on his Honda 1986 VFR750 its never been opened up...thats impressive,more so a testemant to the engineering glory days of Honda. No manufacturer has accomplished what Honda has done cant take that away from them.
But thats apples to oranges,there still not 2-strokes. Different machine, totally different experience

I dont know if I'd really hold a grudge too much to the previous owner,unless you were told it was overhauled at some point,as virtually most RZs you see have been blown up,rebuilt sevaral times over by now,and if not their clock is ticking like a 65 year old man having sex,I either one could expire at at any moment
Your bike from the photos looks better than the average Rz ,given the choice I'd rather face an engine overhaul than,finding all the parts to bring one back into shape.
This next comment usually,pisses people off too, But unless you buy a bike(mailnly a 2 stroke) with reciets documenting and proving a rebuild,IMO you should always ,no matter what the seller says assume its going to need a tear down.
Good news is if you decide to do a solid rebuild,top and bottom end and powervalve rebuild,you can expect an easy 30,000 miles of happy small bike 2-stroke fun,thats alot of weekend fun rides

[BrianT]

I heard from the previous owner Dennis last night and want to apologize if I said anything that reflected poorly on him. He sold me the bike with BOTH of us agreeing that it needed at least a top end rebuild and possibly a FULL rebuild. The price I paid reflected that. I was a little upset at the time because I had just found out that my $400 top end rebuild was now turning into a $2500 full engine rebuild. I apologized to Dennis and asked him to contribute anything else that he may know about my bike or it's previous owners to this thread.

I don't want to turn this thread into a pissing match about reliability of two strokes. This is a 27 year old machine and I am a 49 year old man. I knew damn good and well what I was getting into when I bought this bike.

[cbirk]

Get your hands dirty and you can take that insane $2500 figure down to at least $1000-$1500.

[BrianT]

I have no problem "getting my hands dirty". I also know my limitations. Something caused this to happen.



I could replace the bad parts and probably get the bike running again, but who is to say it wouldn't happen again next year?!? Bill is going to figure out why that cylinder went lean, and hopefully prevent it from reoccurring. Also the coolant that poured out of the crankcase needs to be addressed. I could guess at what's wrong and start throwing parts at the engine, but this could be more costly than paying someone who knows what he's doing to do it right the first time. Then we have to address tuning. I know very little about jetting or timing.

The $2500 number that I threw out there was just a random figure. Bill actually quoted me a number off the top of his head much lower. But then I started asking him about a stroker crank, changing out the reeds, new clutch, ignition plate etc. and the price started climbing. I brought up these changes and Bill agreed that they were worth doing.

To me, it's just makes sense to pay someone and have it done right. BTW, I paid someone to repair my Sony big screen a couple of months ago also...

The good news is that the cylinders don't appear to be damaged and Bill says that the ports haven't been touched. We were afraid that someone may have beat him to the cylinders and he would have to redo their work, or even replace the cylinders. He is putting together a written estimate and I should hear from him in the next couple of days.

[This old RZ]

If you do a simple solid rebuild,then........ just the most basic of mods:

1.) Skim the stock head "see if it has not been previouslly done"
2.) You already have exhaust chambers,keep'em dont change them.
3.) set of reeds simple TDR brand.or whatever...NO need for V-force etc..
4.) stock carbs,rejetted to your location,NO need for larger carbs,Get yourcarbs/ jetting done by a pro. stock Filter or airbox both work just fine
5.) drop 1 tooth on the front sprocket

FOR A LITTLE XTRA SPLURGE ADD:
6.) A decent mild/mid level port job,expensive but adds a fair amount of pwr

This usually will be all you need to have a solid,fun RZ..and dead reliable.

You don t need prog/adj ign,bigger carbs. Sure there are options, If thats what you want its all good but pretty much each one will add a grand to your total. I dont know what you weigh,that is a thought to consider on a small bike like the RZ if your 150-190lbs the RZ will be really fun,If your 200-250,270 etc..then There will be a noticable penalty,and you might consider an increase in H.P. as the bike is tiny,it is what it is..but there alot of fun

[BrianT]

I didn't list everything that Bill is planning on doing to the engine because I don't think he's told me everything...yet. Like some other builders on this board, he has a few tricks up his sleeve and I'm sure he'd prefer that I didn't blab about them all over the internet.

To address some of your suggestions...

1) We plan to address the head by decking and machining. The exact specifics have not been revealed to me yet.

2) I plan on trying to take the dents out of the pipes that I have and reusing them. My buddy has a stud gun, and I take dents out of metal for a living = no charge.

3) He did mention the V-force reeds. He uses them on all of his high end builds. I trust his judgement.

4) WE are going to use a pair of Keihin PWK33 carbs. Bill has a line on some.

5) I looked and am running a 16 tooth sprocket now. That is one less than stock correct?

6) Bill is an experienced engine builder and plans to do a "mid level" port job on the cylinders. Again, he's not telling me everything yet, but I do know that he plans on cleaning things up quite a bit. I saw some samples of his work the other night and it looked very nice.

The comments about the weight of the rider are dead nuts on. I am a little over 200 pounds right now, but am planning to loose a little weight after the first of the new year. My goal right now is to not GAIN anymore weight during the holiday season. I have a real nice HJC motorcycle jacket that I bought a few years back. I sure would like to be able to zip it up again!!

[silverstrom]

Have you considered going back to the stock airbox with stock carbs? It works very well when done correctly. Easy to tune and reliable.

VF reeds are nice, but expensive. There are other options, but he's right, VF is likley best. Carbon Tech also work well as to other carbon reeds. Maybe TDR as well?

Yes, stock front sprocket is 17. 16 will help.

There is plenty of good advice here on the forum. You'll be up and running in no time.

If you decide to go back to the stock airbox and stock 31K00 carbs and need parts just send me a PM. I have everything you need.

[This old RZ]

Dont get me wrong,the Vforce are very good,Its just that there expensive,and not required for a quick RZ,but properly set up carbs with V force has proven to be a good combo. I was just throwing out a the most basic cost effective option to provide a fun base bike. You can boost the power a fair amount by what you have in the works
As far as carbs go,Ive had great results with the stock 26mm,although my preferance is 28mm flatslides. Ive had 30s and 32s at one point years ago, No good for the street ,robs all your low end power ,they rip on a race track but for the street not the best option.My RZ was able to click off hig 11 second 1/4 passes with stock carbs. So ..Ive always been a fan them,Toomey has a great article on their website regarding the theory of larger carbs,and from my experience its proven pretty accurate information,for 80% of street RZs
I also ran the Toomey air filter kit on all 3 of my RZs and never in close to 70,000 miles combined on all three had a running or engine failure,So Im also a firm beliver in the toomey 2-1 filter..But the stock airbox will perform very well and is also a good option,
Your engine issue is probably carb/jetting related it usually is the cause,That is why I recommend ,whatever carb intake you decide to go with,have a professional work out your jetting. It doesnt matter if you have a $1500.00 motor or a $5000.00 one if your jetting is out ..it will suffer and try to kill itself...2 strokes are just SOoooo much fun

[BrianT]

I failed to mention it earlier but the bike has the Toomey air cleaner and battery box kit on it.

[This old RZ]

I failed to mention it earlier but the bike has the Toomey air cleaner and battery box kit on it.

I noticed that from the photos,Nice piece of kit they made. You might have the toomey jet kit installed.Youll have to find specs and see,your crabs couldhave been dirty etc..clogged jets etc.. Theres a number of things ,but if your going with the other carbs,thats fun too. Are the RM carbs similar to the PWKs?? Im out of touch with those,RZs Unlimited offers the entire kit,cables etc but expensive thats why I stated $1000.00 for me thats WAY too much for carbs,an inline 4 with big CRs perhaps but not a twin.
Keep us posted on what you do,and what you found out to be the probable cause of the meltdown.

[BrianT]

I went over to Bill's last night and the engine is completely disassembled. Here is a pic of the pistons out of the bores. Despite what it looks like, the melted piston came out pretty easily and didn't do much damage to the cylinder. He lightly honed the cyl to remove the extra aluminum and didn't find any deep gouges or scratches.



We talked about the build and which direction I wanted to go. I think we are going to use this 4 mm crank from Vito's Performance. It looks like a real nice piece and we are getting a good price on it.

http://www.vitosperformance.com/atv_par ... 200&page=1



I found out some more info on the carbs that Bill plans on using They are Keihin PWK33 flat slides. He said they run $150 a piece plus $50 for the cable. He feels comfortable using and tuning these carbs as he's used them before. The only drawback that I can see is that they use two separate choke levers.

We are also going with a Pingel dual outlet petcock. Hopefully this will keep the right carb from starving for fuel at WOT. The Pingel also features a reserve which is kinda nice.

Bill said he will finalize the rest of the estimate on the rebuild and get back to me in the next couple of days. Things are starting to get exciting!!

[JonW]

Brian, sounds good to me, you were lucky on the bore. I wouldnyt buy a Vitos, I would buy from Roger@Wicked, but otherwise what you said was fine.

You can fit the TZR250 choke setup to the PWKs im told, I have one, its just not fitted yet. it is a single lever unit with two cable operated plungers.

[BrianT]

I wouldnyt buy a Vitos, I would buy from Roger@Wicked, but otherwise what you said was fine.

You can fit the TZR250 choke setup to the PWKs im told, I have one, its just not fitted yet. it is a single lever unit with two cable operated plungers.

I appreciate that Roger is an active member of this forum and have read tons of his posts, but my builder gets dealer pricing from Vito's and is passing some of the savings on to me. We are going to have the new crank checked out before installing it. He says that 99 percent of the time, there's no problem with them, but he has them checked anyway.

I will ask him about the TRZ choke set up. That would simplify things. Thanks!!

[BrianT]

Just a quick update on our progress. I went over to Bill's and did a little detailing work on the frame since the engine is out. Basically, just cleaned everything that I could reach real well with some grease cutter. Nobody will ever see it, but I know it's clean!!

Bill finalized the estimate and I gave him a deposit so that he could get started ordering parts.

He also sold me a very nice pair of low mileage gauges. The needle has fallen off of my old tachometer and I need to take it apart to find out where it went. Bill had a set of gauges off of a 3k mile bike that look like new. I would never represent the bike as having 3k miles, but it should be a conversation starter when people see a 27 year old bike and the mileage reads 3k!!!

Parts won't get here til after the new year, so I don't look for much to get done over the holidays. Just wanted to update this thread.

[aaronmvrider]

nice work ... bet you cant wait..