YZF750/1000R - The Fly 5

Using the 41, just do a "roll-on throttle".
with no ekshaust throttlevalve the thunderace engine is a little "lumpy" in the midrange anyway.. :p
but importent to isolate the intake air from heat of engine and radiator.
 
furu14 said:
Using the 41, just do a "roll-on throttle".
with no ekshaust throttlevalve the thunderace engine is a little "lumpy" in the midrange anyway.. :p
but importent to isolate the intake air from heat of engine and radiator.


That's good to know about isolating the heat. The stock setup used a rubber sheet with heavy aluminum backing to keep the heat off the carbs and airbox.
It was in pretty bad shape so I'm going to have to find a suitable replacement.




Just because it's cool, look down into the intakes at three valves:
3valveIntake.jpg
 
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I hooked it up to the battery in my truck but it still didn't want to turn over well. So, I pulled the plugs and the engine turns over fine. Plugs back in, turns over like it should.


The stock 750 carbs are a bit crusty.
750CarbsOut.JPG
750carbs1.JPG
 
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So it appears the PO did open these carbs at one point because....they lost one of the float needles. I went to the Yamaha dealer just to check and I can get one in a week for 28$, they only sell them as a needle/seat set. The seats on mine are in good shape. I'm going to see what other carbs I can cannibalize for a damn needle.
 
I didn't have any compatible needles that would work so I now have 4 new Yamaha needle/seat sets on the way. I was halfway considering splurging on a set of FCR39's but that's just fantasizing for now.
 
clem said:
Funny how $5 needles can add up when you're sorting things out.

I chuckled pretty hard at least twice reading this in the last few days before I got off my ass and cleaned my bike:

I realized I have non stock goodies:
yzf_clean_1.JPG
yzf_clean_2.JPG
 
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It was so covered in oily dirt down there, I couldn't even tell until I cleaned it. Some of the anodizing has worn down but the aftermarket shock links look like they are in great shape I just need to do a little homework on them. I'm going to leave the stock shock in it and just clean, lube and adjust everything back there.

Post cleaning list of stuff to do next:
- Pull rear wheel, clean, inspect, etc and paint
- Order SS brake line kit
- clean, inspect, rebuild, etc rear caliper from parts bike and install on the titled bike
- clean, inspect, rebuild ,etc front clutch and brake master cylinders and front brakes Same for the rear sets.
 
irk miller said:
Is the DG swinger stock, or is that an aftermarket rig?

Good question. I don't see the DG mark on stock bikes but the swingarms are otherwise visually identical. I'm still digging for history and other fun info on these bikes. My chassis also has a spot on the frame for a steering stabilizer that the newer bike does not.

Todays mail brought more fuel line, needles and seats and a petcock rebuild kit. I usually don't like even screwing around with vacuum petcocks but this mounts to the bottom of the tank. I'll give the repair a shot.
 
Hey... so this is where all the cool kidz are hanging out! :D It took me a while to find you! ;)



There's something 'extra special' about a full litre sportbike. 8) Love the direction you're headed... I wonder where you'll end up? ;D

Excited to follow along. :D
 
Drewski said:
Hey... so this is where all the cool kidz are hanging out! :D It took me a while to find you! ;)
There's something 'extra special' about a full litre sportbike. 8) Love the direction you're headed... I wonder where you'll end up? ;D
Excited to follow along. :D

Glad to have you onboard Drewski. This build should stay on track, I guess time will tell. I hope it does.

Today I got the 1000 motor cleaned up. It cleaned up well, no paint necessary. I also pulled the wheels to prep them for paint. I need to get a chain and sprocket set ordered soon.

I really should get back to the 750 carbs and try to get it started.
yzf1000cleanedup.jpg
yzfwheels2bd.jpg
yzfchassisup.jpg
 
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Some good bits you have to work with there. :D

Any decisions on what way you'd prefer to go with your engine, etc? :)
 
Drewski said:
Some good bits you have to work with there. :D
Any decisions on what way you'd prefer to go with your engine, etc? :)

I like questions. I got my hands on an earlier FZR for a few hours one day years ago while I was stationed in San Diego but I've never ridden a Yamaha like one of these Yzf's. So.
I'd like to know what the 750 motor feels like on the road so part of me just wants to get it running and swap it into my good chassis and ride it awhile. The winner though will probably be putting the 1000 Ace in first and roll the dice. Either way it would be nice to compare the two.

For the Ace motor: The motor mount mods need a little work. The mod plates for the conversion are a bit rough and could use a do-over if I ocd it. I'll likely source a few more engine mount bits and mount it in the good chassis. This while I deal with 750 parts bike and ordering stuff as I can.
 
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