TRI Z Resources and rebuild suppliers.

[this old rz]

Ive looked fairly hard, but still come up short on some engine peforformance or rebuild parts. I am looking for information or leads on the following and any info anybody can provide is appreciated. Also Engine rebuilders you may recommend or info. I want to get this motor up and running and just reliable so I can enjoy it I have two projects that just sit I'm trying to reverse the trend with this so I can have some fun

1985
1.) Is there a drop in rebuilt crank assembly avail?

2.) same w top end rebuild components.

3.) New cooling impeller.

4.) Whats a proven complete gasket kit, & where?

5.) ANY basic Tri Z tips & tricks you can provide.

6.) Okay I don't quite understand what that one fuel vent tube comes from the fuel system into the crankcase I must say I have never seen that?

7.) Finally a replacement carb that is proven and very easy for a novice to work with and around as far as I know my motor is so a 34-36 mm ? or similar I feel would be just fine. In in Calif basiclly @ sea level. I feel a nice new carb just might be a good option to help alleviate any simple set up headaches? So tell me what works and what you guys like and what is definitely compatible with the Tri-Z.

[jonolanracin]

The vent tube from bottom of cylinder is to operate the vacum fuel pump. The oem water pump impellar are still available new . eithet vesrah or cometic gasket kits are ok but i always use a oem head gasket.a 38 pwk carb is easy to find and a good option. I have seen complete rebuilt cranks for sale on feebay often or just find a Good machine shop to rebuild yours and the piston kits are easy to find as well.the best tip i can give is to make sure your temp light in the top of the headlight housing works so you should never ruin a motor from overheating

[this old rz]

Are the rebuilt cranks on E-Bay specifically for a TRI- Z? That means but it & drop it in not a YZ that needs to be modified? Ive looned for 2 weeks & cant licate anything TRI Z specific..Maybe I need glasses and my hand held..l but Ive had zero luck.

Are OEM Gaskets as easy as me ordering from a licenced Yamaha parts dealer ? Maybe Chapparal there about a hr from where I live.

Temp light..lol news to me. Does the Tri Z have a cooling issue or poor design, as Ive had other aircooled & watercooled 2 strokes bikes RDs & RZs that could go forever w no hint of "trouble", maybe hot but not fatal? Let me know

Finally any recomended shops in So Cal that can do a " bare bones" rebuild for a reasonable price. One shop in Rancho quoted me well over 3k for a bone stock rebuild...thats just absurd & silly!
Im familiar with Klemm , & thats in the radar but thats down the road right now I just want a bike to ride for the next year ir two. While acummulating parts!

[jonolanracin]

The tri z doesnt have any cooling problems its just i like for my temp light to work the last time i looked there was a rebuilt crank on ebay

[arlaunch]

http://www.powersportsdiscount.com/o...-ytz250n-parts

http://www.powersportsdiscount.com/o...-ytz250s-parts

[newby200x]

I've never used these people before, but they look legit... www.mrcrankshaft.com

[this old rz]

Thanks guys! Gotta say 3wheelerworld might just be the best website I've ever stumbled across.

[sledcrazyinCT]

http://www.partzilla.com/parts/detai...450-00-00.html


http://www.ebay.com/itm/1983-1987-Ya...item360c3d3f51

Links to billet water pump impeller and OEM replacement

[El Camexican]

You have a bunch of good answers already, but here's my $0.02 anyway

1.) Is there a drop in rebuilt crank assembly avail?
Unless yours is damaged I'd just put a new rod on it and change the main bearings and seals in your cases

2.) same w top end rebuild components.
Any idea what your current piston diameter is? I think 70mm is the last bore, after that you'll need to get yours sleeved, or buy a decent used cylinder. You can buy a Sprock Cool Head. I have one, but it's not a must.

3.) New cooling impeller.
As said, still available from Yamaha, but there are stainless steel ones out there as well.

4.) Whats a proven complete gasket kit, & where?
I've used Athens and Vesrah, no issues with either.

5.) ANY basic Tri Z tips & tricks you can provide.
I'll save this for last...

6.) Okay I don't quite understand what that one fuel vent tube comes from the fuel system into the crankcase I must say I have never seen that?
Like the man said, it powers your fuel pump. Make sure it is in good condition. A fuel pump rebuild would be a good idea. I think the kit is for a Round Mikuni DF52. They are about $20 bucks.

7.) Finally a replacement carb that is proven and very easy for a novice to work with and around as far as I know my motor is so a 34-36 mm ? or similar I feel would be just fine. In in Calif basiclly @ sea level. I feel a nice new carb just might be a good option to help alleviate any simple set up headaches? So tell me what works and what you guys like and what is definitely compatible with the Tri-Z.
The PKW 38 mentioned seems to be the most popular. If you can get a used one off a snowmobile better yet (long story)

Back to #5... I'm no expert, but I know exactly what I'd do if I ever came across a stock Tri-Z that I wanted to trail ride reliably.

- Rebuild the bottom end with a new rod and bearings and install a new water pump impeller
- Clean up the base of the cylinder where the transfer ports meet the liner. They are horrible from the factory
- Polish the exhaust port
- Raise the exhaust port 1mm and widen it 1mm
- Widen the stock boost port 1mm and make it 2mm taller
- Shave .5mm off the head
- Buy a Sprock manifold (unless the stocker is in good condition)
- Put Boyesen reeds on the cage. There is a V-Force reed block that many like. I think it's for a older KX125. I had a bad experience with V Force, so not for me
- Put a DG pipe and silencer on it. May not be the ultimate, but if I bash it in I can replace it for a couple hundred bucks
- Use the stock exhaust snout collar, or buy a replacement from the 3WW store and add a third spring mount on the right side of the cylinder to prevent leaks
- A Keihin PKW 36
- Use a BR9ES plug to keep the temperature a little lower

That's it. It would run on pump gas, be very reliable and be a fair bit quicker than a stocker.


Read this if you haven't, http://www.quadpit.com/mags/1985/3-4...t-tri-z.htmbut

Don't do the second boost port mod. It's too risky and weakens the cylinder, mine came with one, so I'm stuck with it. Some guys weld the cylinder and then add the port, but you're starting to spend some money at that point and there would be a cascade of other expenses to follow. If I was to ever do a no expenses spared build I'd likely contact Klemm about their bore kit that Bryan Raffa has posted about. You can see it run on YouTube.

[this old rz]

Awesome group of replies, and seriouslly I'm very grateful for all your help. I'll post some seperate posts regarding specific questions & topucs, then I will post pictures in a specific thread when I get a clear idea of everything, so its better organized. My bike..I LOVE IT! I just bought it it cost me $600.00 out of pocket. It has some fun features, like a + 6" swingarm ( my two friends Tecate & 250Rs have the same..so it will B fun). A top mounted fuel tank conversion( Not to practical for anything other than a moto-x or flattrack bike) but really cleans up the lines. (I got all the stock fuel parts as well! ). New tires , w 2 new douglas rims. I was told the motor has the "wrench report" done to it( but without opening it up, I havent verified that yet.)