Phase II wrench reports reviews

[Tas Wheeler]

Hi all,

I know this topic has been discussed numerous times before, as I believe I have read every thread on the topic here and elsewhere.

But I woukd like to hear some reviews form the guys that have done it weather it really is like it states in the report and would make quote " experienced pilots scream in delight, less seasoned riders will shiver and curl up at the explosive, light switch type of acceleration. "

Has anyone done the engine mods word for word, part for part, for example used the exact carb and jetting suggested and moved the air box etc.

I'd also like to know what is is like in different environments like trail, track, hill climbs, dunes etc etc.

Cheers Matt.

[christph]

I've done all the mods on the wrench report except raise the exhaust port height. I didn't want to risk loosing any bottom end. Some of my mods involve different brands because they weren't available at the time but the practical effect is the same. I have a Sprock cool head (which also raised the compression to where I have to run 50/50 race/pump gas), V-Force reeds, reed spacer, 38 mm Keihin carb, Sprock impeller, K&N filter, and DG pipe. I noticed the biggest improvement when I put in the additional boost port (see Wrench Report) and then the reed spacer. Without the spacer I don't think the ports and reeds flow at their full potential. The Tri-Z engine can be pretty impressive with the right modes. If you are debating on whether to do it I wouldn't hesitate.

[Tas Wheeler]

I've done all the mods on the wrench report except raise the exhaust port height. I didn't want to risk loosing any bottom end. Some of my mods involve different brands because they weren't available at the time but the practical effect is the same. I have a Sprock cool head (which also raised the compression to where I have to run 50/50 race/pump gas), V-Force reeds, reed spacer, 38 mm Keihin carb, Sprock impeller, K&N filter, and DG pipe. I noticed the biggest improvement when I put in the additional boost port (see Wrench Report) and then the reed spacer. Without the spacer I don't think the ports and reeds flow at their full potential. The Tri-Z engine can be pretty impressive with the right modes. If you are debating on whether to do it I wouldn't hesitate.

Thanks for the reply.

That's the sort of info info I'm after. I see you have mentioned and others also on previous threads the potential loss of bottom end with the raised exhaust port, anyone have any experience with the raising of the exhaust port the 1.5mm or the full 2mm and was the loss that great or noticeable?

Also on your running of the K&N filter did you just mod the existing air box or remove it fully and do something similar to the report?

Definitely not hesitating, just debating on what suits my intended use.

What type of riding do you use your Z for and how do the mods perform?

[christph]

If I remember correctly even the Wrench Report suggests the engine is pipey and heavily biased towards the top end, and I didn't want that. If you increase the port timing by raising the exhaust port you get more top end but at the expense of the bottom end. I spend most of my time riding on a mix of trials and fire roads, so I wanted an all-around engine. Besides, even without the raising the exhaust port my Z has a kick ass top end. If I were you I'd do all the other mods first, ride it, and then decide if you want more top end. Once you raise the exhaust port you can't undo it.

Regarding the K&N filter, I just bought the one made for the stock intake and ride with the lid off. I've toyed with making an aluminum airbox and locating right above the carb, I just haven't done it yet. I'd also like to make an aluminum tank but I'll have to practice my TIG welding more.

One problem I did have initially was keeping the engine temps down. The Z doesn't have a very efficient cooling system, especially for a heavily modded engine. I got a Sprock impeller and some Engine Ice and I no longer have a problem with overheating.

After all these mods I'm very impressed with how it runs. It is a great all-around engine that pulls on the bottom and screams on top. And be sure to try a reed spacer. My engine didn't perform to its full potential until I put one in--I start a thread on this. I got a bunch of people trying to tell me they don't work and it was apparently my imagination. BS. I did a back-to-back comparison and there was a significant difference with the spacer. I think it pulled the reed block away from the ports and allow the reeds to fully open.

My next project is to tear it down, repaint the engine, frame, etc. I plan on keeping it the OEM colors. Here are some pics.

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Good luck with your project.

[Ryah]

I did have a 1985 1/2 TriZ with all the Wrench report mods. I did raise the exhaust ports to the mentioned specs. But I didn't mod the stock pipe, mine came with an aftermarket Bills pipe. I replaced the Mikuni with a Keihien PJ38mm and had Delta Vforce 2 (came from a snowmobile kit, so you got two at the same time so you could split the cost with someone else with a Triz) reeds set at the bottom end power setting. The bike was ridden primarily in the sand at Glamis and it would lug down with no problem, so bottom end loss is not a concern. It will have plenty compared to what it was stock. I did take off the airbox system and just added a piece of pvc pipe on the 90 degree elbow off of the stock carb intake boot (heat the boot in boiling water and it will fit on a 38mm carb) and trimmed the rear fender a little bit to fit it the largest K&N filter under the seat. Even with a 5 speed with stock gearing it would pull many built bikes hill shooting, and it wasn't built as a hillshooter but just a casual duner.

[Tas Wheeler]

Cheers again for the replies they both have been very helpful.

As with your mods Christph and with most of the posts and threads around on the wrench report mods, they mention only usually doing half of the recommended porting and then a mixture of the standard air box or a half modded box and then on top of that the cut factory pipe or then even a dg pipe, which don't always usually get a great wrapp compared to some of the other pipes previously available, it just got me wondering.

Now I would never claim to know the ins and out of everything, and correct me if I'm wrong, but to my way of thinking if the wrench report mods were followed completely then using a decent pipe and doing the complete air box mod this should help the loss of bottom end some.

I know there is always going to be some bottom end loss either way with raising the exhaust port and I also understand the lack of availability of most of the parts now.

As I have managed to find a completed bassani pipe I will most likely be doing the complete Phase II mods as close as possible to the report and/or very similar to what you have done Ryah, at some stage in the near future, I was basically after some more thoughts from those who have completed the phase II mods fully as close as possible and what environment they are usually used in.

Thanks again for the replies and my apologies for the novel length reply.

Cheers.

[barnett468]

Hello;

As mentioned, once you raise the ex port you can not go back. unless you want a bike that possibly has a light switch power band and all mid to top end with less bottom i would NOT raise the ex port at least yet.

A Bills pipe is NOT a Bassani pipe. they work deliver power in different areas. christph has a bassani. i would go off his recommendations for that reason.

If you do any moderate speed kinda laid back trail riding, you will HATE, HATE, HATE your bike if you raise the ex with the bassani pipe. if you want an all out pro type power band. then go for it.

Unfortunately you can not have your cake and eat it too, but you do have the opportunity to leave the ex port alone, ride with the bassani then decide.

Here's the deal, if you want more bottom end with the bassani, do NOT touch the ex port, if you want LESS bottom end with a more violent power delivery and more top end then grind the bejesus out of the ex port.

It's a piece of cake to remove the cyl so no big deal.

Don't do something by guessing that you can NOT undue.

ALSO, without raising the ex, i might only put a 36 on there, the 38 is a bit large imo. i would also run an old school $99.00 mikuni vm style carb. When PROPERLY tuned, it will work just as well as any space age death slayer 2000 octoport carb made from prefabulated amulite, i guarantee you. the air stryker is a fine carb too as well as some others but if you're on a budget or a super sensitive rider, you will never be able to tell the difference between any of them.


try it with and without a reed spacer BEFORE you do any ex port mods. reed spacers can actually REDUCE power, yup sure can, however, this is not always a bad thing. they can soften the power band. in others words they can make the deliver smoother and less violent. i ran one on my 78 YZ400 pro bike because it was so violent it was difficult to get traction.

If you determine that you want to raise the ex you can raise it just .75 mm. and try it like that.

If you don't want to raise it but want a little more mid range and possibly a touch less bottom end you can widen the ex around 1.0 - 1.25 mm on each side, but this should be done by a knowledgeable cyl porter.

Increasing the compression will give you more power everywhere with no loss anywhere but you will need to run race gas.

you can also try advancing your ignition timing a hair if it is adjustable. different bikes and set ups respond differently to this. most companies are conservative with ignition timing and can therefore benefit from a hair more, especially if mods are done to the engine. Kawasaki...builders of the fastest production 3 wheeler in the world are just the opposite. We LOVE ign timing and engines that ping. NEVER advance the timing in ANY Kwasaki or you might end up with an engine full of shrapnel, lol. you should hear it detonate if you advance the timing too far, just listen closely for it right when you roll the throttle on or when accelerating under load like going wot up a hill etc..


OMG...I just knew he'd get thatKawasaki plug in there somewhere!
http://www.freesmileys.org/smileys/smiley-laughing025.gif (http://www.freesmileys.org/smileys.php)

:beer