Topic: 76' cb750k build part 2, GSXR conversion

[wolfbiker88]

that header wrap is supposed to be soaking wet when you install it so that it stretches. once it dries it shrinks/tightens everything up.

[Elan]

that header wrap is supposed to be soaking wet when you install it so that it stretches. once it dries it shrinks/tightens everything up.

I was told that the titanium wrap is supposed to be applied dry.. BUt those were that same people that said I didnt need gloves too haha.  Im not too worried, It had a lot of stretch to it already, so its quite tight.

[Elan]

ok motor out...(and see my new graphic on the tank back there?)


head and cylinders off...



out with the studs, think I can reuse them? 



THe bendy trick worked great, they came out sooo easy. I got some APE studs going in.

made some graphics for the side covers too...

The inter part of the lettering is reflective.

oh, can't forget the Mrieck special....


she's got a little porting in there, and oversized intake valves.  I suppose it would be a sin not to upgrade the cam at this point....

[Elan]

made some purchases.

webcam 41
all new rocker arms and screws.
adjustable cam sprocket
dial gauge

 

now if I can figure out how to degree the thing

[Elan]

Ok definately need to make bigger valve pockets on the pistons. I've been reading and trying to wrap my head around it. Made a little drawing to make sure I'm getting it. Is this right?


Mainly want to confirm that the piston height should be 10 degrees away from TDC.

I'm going to take an extra head I have, remove the valves, and put a punch through the guide. This wil give me the center point of the valve at the piston. From there, I should be able measure out how much bigger the pocket needs to be...

[Dannodarko]

Awesome build!!!!

[MRieck]

Engine is ready to roll after some top end work.

[Elan]

special delivery. thanks again mike!

[Elan]

Ok up and rolling again!


I upped the main jet to 118 before starting, did a little cruise and it seemed to stagger a bit when I accelerate. But once it "catches up" it would really move! It did seem hotter than usual too. pulled a plug and saw this....


Maybe a bit lean, upped the main to 122. Did a cruise and it seems a better, but maybe I should go to 125.

Also I might have to play with the idle jet and air screws... Im having trouble getting  a steady idle. When I bring the idle down to 1200-1400, it will stay, but after I blip the throttle, it will start going down down down.. any suggestions?

[Elan]

so when I lay down the throttle, it would just struggle. upped the main to 122, no change. upped to 130, no change..

Im gonna look at the plugs tomorrow to see if they are getting darker, and maybe up the main to 135 to see if I get anywhere...

[MRieck]

so when I lay down the throttle, it would just struggle. upped the main to 122, no change. upped to 130, no change..

Im gonna look at the plugs tomorrow to see if they are getting darker, and maybe up the main to 135 to see if I get anywhere...

Did you go up 1 size on the pilot jet Elan. The main will have very little effect on cruising speeds. I check the plugs after easy riding and use that (and other things) to size the pilot jet (which you are on most of the time). I believe you have new carb boots on there right?
  Mike

[Elan]

so when I lay down the throttle, it would just struggle. upped the main to 122, no change. upped to 130, no change..

Im gonna look at the plugs tomorrow to see if they are getting darker, and maybe up the main to 135 to see if I get anywhere...

Did you go up 1 size on the pilot jet Elan. The main will have very little effect on cruising speeds. I check the plugs after easy riding and use that (and other things) to size the pilot jet (which you are on most of the time). I believe you have new carb boots on there right?
  Mike

. Ya carb boots are new. I didnt tough the pilots.  Its happening when I heavily accelerate at around 5k. You think I should go up a step on the pilot? I find myself never finding te perfect idle too. I set it and it moves 10 seconds later.

[MRieck]

so when I lay down the throttle, it would just struggle. upped the main to 122, no change. upped to 130, no change..

Im gonna look at the plugs tomorrow to see if they are getting darker, and maybe up the main to 135 to see if I get anywhere...

Did you go up 1 size on the pilot jet Elan. The main will have very little effect on cruising speeds. I check the plugs after easy riding and use that (and other things) to size the pilot jet (which you are on most of the time). I believe you have new carb boots on there right?
  Mike

. Ya carb boots are new. I didnt tough the pilots.  Its happening when I heavily accelerate at around 5k. You think I should go up a step on the pilot? I find myself never finding te perfect idle too. I set it and it moves 10 seconds later.

[/b] It sounds like an air leak ....mayber around the air screw o rimgs. A guess.

[Elan]

upped pilot to 42
needle position from 4th to 5th position
main is at 140 (130 in dynajet numbers)
mixture 1 turn out

I just learned that dynajet numbers are different that keihin. SO I thought I was at 130 on the main but Im really at 140 I guess.


BIke is running much better.  Low and mid feel great. Much less hesitation at WOT, but still a bit of hesitation up top. I pulled a plug(ill pull all when I get a chance) and it wasn't too dark.

The idle is still tricky. after warmed up, I set it to 1200 and it would stay steady, until i blip the throttle and then it would go down to 800-900. I'd reset, drive around, and then it would be at 2k.  I replaced the orings in the mixture screws. People say to test for air leaks by spraying carb cleaner- I'm not about to spray carb cleaner near my newly painted engine...


lastly, there seems to be a small amount of smoke coming from the oil tank vent. Its white, so just condensation?

[Elan]

pulled the plugs today, still a little lean. This is not a plug chop, but full range.  It sounds crazy, but i might try a 145 main. But first I'm going to try it again with the d8ea plugs. THe iridium plugs i had were resistor and so were my caps.

again, heres the specs:

836cc
ported and oversized intake valves
webcam 41
opened up air box
140main
42 idle
needle all the way up (clip all the way down)
4 into 1 mac with no packing

[MRieck]

Try the standard plugs elan and turn the air screws in 1/4 to 1/2 turn....I believe they are 1 turn out. This will supply more fuel throughout the RPM range. Try different mains after that....those are large.
 Also...check those carb boots for leakage. new ones will leak if overtightened. Spray some WD40....it will do the same thing as carb cleaner (plug the leak for a few seconds).

[Elan]

Try the standard plugs elan and turn the air screws in 1/4 to 1/2 turn....I believe they are 1 turn out. This will supply more fuel throughout the RPM range. Try different mains after that....those are large.
 Also...check those carb boots for leakage. new ones will leak if overtightened. Spray some WD40....it will do the same thing as carb cleaner (plug the leak for a few seconds).

Try the standard plugs elan and turn the air screws in 1/4 to 1/2 turn....I believe they are 1 turn out. This will supply more fuel throughout the RPM range. Try different mains after that....those are large.
 Also...check those carb boots for leakage. new ones will leak if overtightened. Spray some WD40....it will do the same thing as carb cleaner (plug the leak for a few seconds).

Ok so I put the d8ea plugs in, and turned in the mixture screw 1/4 (its now at 3/4).  BIg improvement. its no longer staggering at WOT.  I drove it about 2-3 miles and pulled the outer plugs... still looking quite lean, or maybe I just haven't ridden it long enough? maybe another 1/4 turn?


Also the idle is still being weird. I sprayed the boots with wd40 at idle and there was no change in rpm. Heres a video of its behavior...

http://s1026.photobucket.com/albums/y321/elan_morales/?action=view&current=4511CC76-0B87-41F1-8FBF-2E448E557CE3-636-00000040C438BC8C_zpsb90e3280.mp4

[MRieck]

Turn them in 1/4 more Elan.
 

[MRieck]

Also.......you need to look down into the insulator tunnel to see how it is burning. The tip is not a real accurate indicator. I have a plug magnifier which has a built in light to see down there. You can use a magnifying glass with some type of fixed light to illuminate the area.

[Elan]

Haven't gotten around to check the plugs since turning it in more, but the idle issue is still the same. Maybe I should up the idle jet again...

And on another note, this just arrived in the mail, oooops.

[750resurrection]

Try the standard plugs elan and turn the air screws in 1/4 to 1/2 turn....I believe they are 1 turn out. This will supply more fuel throughout the RPM range. Try different mains after that....those are large.
 Also...check those carb boots for leakage. new ones will leak if overtightened. Spray some WD40....it will do the same thing as carb cleaner (plug the leak for a few seconds).

Try the standard plugs elan and turn the air screws in 1/4 to 1/2 turn....I believe they are 1 turn out. This will supply more fuel throughout the RPM range. Try different mains after that....those are large.
 Also...check those carb boots for leakage. new ones will leak if overtightened. Spray some WD40....it will do the same thing as carb cleaner (plug the leak for a few seconds).

Ok so I put the d8ea plugs in, and turned in the mixture screw 1/4 (its now at 3/4).  BIg improvement. its no longer staggering at WOT.  I drove it about 2-3 miles and pulled the outer plugs... still looking quite lean, or maybe I just haven't ridden it long enough? maybe another 1/4 turn?


Also the idle is still being weird. I sprayed the boots with wd40 at idle and there was no change in rpm. Heres a video of its behavior...

http://s1026.photobucket.com/albums/y321/elan_morales/?action=view&current=4511CC76-0B87-41F1-8FBF-2E448E557CE3-636-00000040C438BC8C_zpsb90e3280.mp4

Thanks for that video.

I read somewhere if your rpm's are coming down slowly like that it indicates a rich mixture, which makes sense of course.

From your video, the way it acted was consistent twice in a row going into a too low idle before you tweaked the throttle and got it stable again.
I think that might be one goofy idle circuit.

Have you tried a manometer balancing lately ? Maybe that's it ?

[Elan]

carb adjusting has gone on hold for now.. I got an 04 gsxr front end going on now. Still trying to locate the upper triple clamp for less than $60 bucks. THeres a lot of tech in these things. the build quality is superb. Bearings ordered. Got a spoked harley rim. hayabusa rotors.

If anyone else is doing this conversion, check out this page for very useful info on gsxr front ends. dimensional info is so hard to find!

http://www.svrider.com/forum/showthread.php?t=135430

[scottly]

Thanks for the link with the measurements! Curious, what happened to the upper triple? Are they like early 750 "unicorns", that often cracked?

[Elan]

Thanks for the link with the measurements! Curious, what happened to the upper triple? Are they like early 750 "unicorns", that often cracked?

Ya I don't know why the 03-04 gsxr1000 triple are so scarce. I actually just picked up one tho. Hopwfully gonna get the triple on the cb this week.

[sabideefoo]

Great JOB ELan...Just spent 30 minutes catching up...You inspire me to do a build thread once that frame gets in.   Nice forks BTW!!!! Im soo jelly.   Im prob. gonna go with the 600RR upside down ones...Might run alittle cheaper.  But if all else fails on budget then prob stick to all my f3 parts hehe...