• Welcome to the Yamaha FZ1 Forums. Member registration disables ads and allows you to post and share. Register Here.

Gen 1 Full Exhaust Swap

Klurejr

Klurejr

Wizard
Joined
Aug 12, 2011
Messages
1,924
Location
Oceanside, CA
Visit site
I just recently purchased a 2003 Gen 1 to replace my 2002 Gen 1 that was salvaged in an accident.

The 02 bike is still in good shape and I want to pull a few things off of it.

one, the old bike has a full Yosh exhaust system, i did not realize that until today when I thought I was just going to swap the "slip ons" and found that the old bike does not have the EXUP box on the bottom of the exhaust.

What I am mostly interested in is the sound I got with the old bike.

I did some reading on Pat's Motorcycle Page and found some good info, and I could care less if the HP gains are only above 8k rpm, I just want the sound.

I am pretty sure my old bike is jetted, but I have no idea what kind of kit is in it, etc, etc. The guy I bought it from knew nothing about the mods on it.

Does anyone know of a good source for instructions on a full swap? Will I need gaskets where the headers meet the engine? Will I have to pull the radiator off?

I will take some pics of both bikes and post them up later today, for now I am just going to work on swapping the rear fender delete as this exhaust job is going to be bigger than I initially thought.
 
Well I don't know for sure about the radiator, but it would probably be easier with it out of the way.

I'm pretty sure you'll be able to reuse the exhaust gaskets. They are made out of copper. I have had the headers on my '06 on and off three times and still using the stock gaskets w/o any issues.

If you do the full exhaust you'll definitely need to put in a jet kit. Why not swap the carbs from your old bike since it ran ok with the full Yosh exhaust?
 
pics of the exhaust on my old biike:

20130727_131848_zps75340e2e.jpg


20130727_131854_zps5381af20.jpg


Def a full system. I tried to pull the silencer can off the bike as if the old one was just a slip on, and found the stock exhaust to be nearly a centimeter bigger in diameter than the Yosh pipe, so no go on that. I will have to pull the full exhaust off the old bike and swap it over.

So I am guessing that means I will have to swap the carbs as well since they are jetted for the exhaust (I can only assume since the guy I bought it from knew nothing about the setup). Is that a big deal? How much time am I going to have to plan for this? I basically spent a few hours this afternoon and got nothing accomplished.


I thought I would be smart and move the fender delete kit over from my old bike to the new, but it turns out I will have to swap the entire under-body plastic part that also hold the battery and much of the electronics and part way in on the old bike I realized it was gonna be a bigger pain than I originally thought so I put the whole thing back together....

I might just cut part of the stock fender off my new bike to slim it down some and stick with the stock rear signals. Unless I was doing something really wrong, it seemed like a lot of work to get that entire plastic part off the one bike and swapped to the other.
 
Monday morning bump.

Has anyone done a full Exhaust swap before on the Gen 1? Can it be done with the Radiator still attached? or is it worth the hassle of draining the coolant and pulling off the radiator to do the swap?

On my old bike it is not a big deal to pull everything apart since I need to get the radiator fixed/replaced, I am just concerned with the time involved on my new bike since I need it as my Daily Driver.
 
take the time and get the radiator out of the way, it's 10 times easier

careful with the exhaust nuts, soak them in wd40 or some other penetrant fluid over night, it's an easy job that can turn ugly

have fun
 
donoharm said:
take the time and get the radiator out of the way, it's 10 times easier



careful with the exhaust nuts, soak them in wd40 or some other penetrant fluid over night, it's an easy job that can turn ugly

have fun
Click to expand...

Oh My, you were not kidding, having the radiator off made a huge dif. I went ahead and pulled the radiator off my old bike this weekend and then took off the exhaust system. I am not sure I would have been able to get the headers off with a radiator in the way. Now I will just have to plan accordingly when I go to install it on the new bike and figure extra time for radiator draining and removal.

The bolts were actually not an issue, it was the part behind the bolts that holds the headers in place(gaskets?). Those guys did not want to come off the stems. I had to bang, pry and wd-40 those things for at least 30-40 min to get all 4 off. I am not looking forward to installation, and hopefully that part on the stock exhaust is not as hard to pull off as it was on the Yosh headers.

I will post a pic later of what I am talking about, my hands were so dirty I did not want to touch my phone during the process.

The old headers are pretty dirty, I am wondering if I should try to clean them up to get the brass to shine, or should I consider doing a wrap on them to make a more undercover look. Has anyone wrapped their headers before? Any downsides to doing that?
 
New Question.

Since I "think" the old Carbs were jetted for the full Yosh Exhaust, I am thinking my best coarse of action is to swap the Carbs or the jets when I go to move the Exhaust systems around.

So I kinda have a multi-part question:

1: Would it be easier to swap the carbs or just the jets? I am hoping to do the swap on a Saturday afternoon and have the bike ready to go on Monday morning for my ride to work.

2: Is there an easy way for me to check the Jets on the old carbs/bike to see if they were properly jetted for that exhaust?

The Previous owner knew nothing about the mods on the bike when I first got her. I am not sure if this is symtomatic, but my old bike(Full Yosh Exhaust and possible jetted carbs) required warm up time, and would have to sit on the choke for at least 2-3 min before I could ride off without stalling, and even then on cold mornings she would sometimes stall out when coming to a stop.
My new bike however (full stock) barely needs the choke to start up, and once started I pull the choke off immediately and she purrs like a kitten and can be ridden right away with no issues.

The old bike never had stalling issues once warm, it was only a cold thing. I just want to make sure I do not swap the carbs for nothing if the jetting was never done right.

Thanks.
 
there's no easy way to check.. it's not that hard either :)

If you swap .. check jets, floats level !!! , MEMBRANES for cracks punctures, very important.... then clean thoroughly , and it's a good time to lube the throttle cables .
It will take about 3-4 hours to do it right and a few coffee breaks.

L.E.
I also deburred all the jets cavities,inlets and all the asperities you shouldn't find in such a performance machine, it may be placebo but i think my bike got even smoother after that.

another thing, take the floats completely out (before leveling/height set) and clean behind the float valves,there's always gunk and rust over there also check the o-rings on them little suckers
 
Last edited:
My working knowledge of Carbs is very limited. I am not even sure what to check for.... but again my biggest question is should i swab the entire carb, or just pull a jet from each bike to see if they are the same or not.

To my little knowledge I thought that jets have numbers etched on them, so if they are both stock that should be evident??? right?
 
donoharm said:
yup

If I were you I'd just clean the stock carbs and ride till you get Ivan's jet installed.
Click to expand...

so, if the Jets on my old bike are modified, it is not worth moving them over?

I am just afraid of putting the full Yosh on my new bike and running too lean and doing harm of some sort to my bike..... I do not want to spend $120.00 for a jet kit if my old bike was done right.

I could call Ivan's and ask how to identify the jets I guess... I read up on his site and there is def a difference in kits for a slip on verses a full exhaust.
 
another thing to keep in mind, your carbs may be synced for you old bike, but you will need to sync them again when you install (whichever) carbs.

I changed over a bank of carbs that ran GREAT to a different bike, and it ran like poo-poo. Any carb work will require a sync for no two setups are really identical.

Look at Pat's page again, believe he specifies OEM jets and Ivan's sizes as well.
 
BroHay said:
another thing to keep in mind, your carbs may be synced for you old bike, but you will need to sync them again when you install (whichever) carbs.

I changed over a bank of carbs that ran GREAT to a different bike, and it ran like poo-poo. Any carb work will require a sync for no two setups are really identical.

Look at Pat's page again, believe he specifies OEM jets and Ivan's sizes as well.
Click to expand...

I will have to research syncing... Never heard of that, but I think I understand the concept. I will check Pats page again for details on the jets, thanks.

Would you consider just swapping the jets or the entire carb?
 
well, easy route, would be to just swap, and hope for the best (after syncing). However, if you have any problems, you'll be tearing into anyway trying to make sure it is clean and everything to spec.

Pat's does a good job of breaking everything down, with pics, but sometimes it is just fun to tear into and sort the details out later.

I had never done any sort of carb work, and was successful in my attempt, with a few questions here/there.
 
Klurejr said:
so, if the Jets on my old bike are modified, it is not worth moving them over?
Click to expand...

"jet kits" may include more parts modifications than just jets moving only the jets may or may not work

Klurejr said:
I am just afraid of putting the full Yosh on my new bike and running too lean and doing harm of some sort to my bike..... I do not want to spend $120.00 for a jet kit if my old bike was done right.

I could call Ivan's and ask how to identify the jets I guess... I read up on his site and there is def a difference in kits for a slip on verses a full exhaust.
Click to expand...

I'm sure stock carbs will handle the full yosh on the street.
 
donoharm said:
I'm sure stock carbs will handle the full yosh on the street.
Click to expand...

What would be the harm in just putting the full Yosh system on my new bike and leaving the carbs alone? Pats page said the bike would run too lean without a re-jet on a new exhaust.

My main goal here is sound not speed. The bike is fast enough. I just figured using my old system would be cheaper than buying a new slip on, otherwise I would be looking at a Yosh Slip on.


Thanks for all the suggestions and advice so far.
 
I saved the stock jets, neddles, drill bits and instructions for my Ivans kit. I will dig it out and give you all the specs if you would like. You could pull your old carbs apart and see whats in there. To make it cold start easier you just need to adjust your floats. I have that spec too. If your old carbs were modified the needles will have little notches on them. That would be an easy check.

Sent from my LG-MS770 using Tapatalk 4 Beta
 
M.Martin said:
I saved the stock jets, neddles, drill bits and instructions for my Ivans kit. I will dig it out and give you all the specs if you would like. You could pull your old carbs apart and see whats in there. To make it cold start easier you just need to adjust your floats. I have that spec too. If your old carbs were modified the needles will have little notches on them. That would be an easy check.

Sent from my LG-MS770 using Tapatalk 4 Beta
Click to expand...

That would be awesome!

I Think I will start with swapping over the full system this weekend and see how she rides, and then work on taking apart the old carbs from my other bike.

I don't want to sell the full system and purchase a slip on because my goal is to setup my old bike with the stock exhaust and sell the bike as complete and running.
 
You must log in or register to reply here.
Back
Top