Dynojet kit or not?

I've been having a few issues with my 82 GPz750. When it is cold it difficult to start. It takes a few cranks and once it starts it will not idle. I have to keep the throttle cracked otherwise it will die. Even after I ride it a few blocks I still have to work the throttle to keep it running at stop lights. It is only after about 20 mminutes that it will idle on its own. Even then it idles unevenly (like it has an aggressive profile cam). Also, when at an even speed it has a little bit of a lean surge that cleans up when you get on it. I've had the carbs apart for cleaning in the past and I think I need to do so again since it sat for a few months this winter and spring. Since I was going to have the carbs apart anyway I was wondering if it would be a good time to install a dynojet kit. It has the stock jetting now but I am running a Kerker 4 into one and will eventually go to a K&N in the stock airbox.

My question: Is the dynojet kit worth it? Or should I save my money and just fatten up the main a bit and be done with it? Stage one or two If I do decide to go with the kit?
TIA,
Jim

maybe you can get some hotter plugs. i heard they help with cold running bikes.

Would bear in mind that the reported issues likely didn't exist when the bike was new and running with its new carbs.

Good Fortune!

save your money,did you do anything to the carbs to compensate for the header?

Patton wrote: Would bear in mind that the reported issues likely didn't exist when the bike was new and running with its new carbs.

Good Fortune!

I agree. I don't know how much of it is dirty carbs vs. the 4 into 1 but I figued while I had the carbs out... I just want to know if the kit is worth it.

wireman wrote: save your money,did you do anything to the carbs to compensate for the header?

No it still has the stock jetting. One of the reasons I thought I would need kit would be the 4 into one and the K&N which I have not installed. Granted, I do need to tear them down for a good cleaning. This is one of of those "while I am at it..."

I have the same issue with my 80 750.But i got an 810 kit,V&H and pods.It's the "Slow Jet" Kaw put a super lean #35 slow jet in.I got NO power under 3,500 rpm.I tried Jets-R-Us,but the jet head is too large for the jet screw hole.Guess I'm gonna have to ream it out.Good luck.

Since I just went through this on another members Police special with BS34's.....

Seriously speaking, to start this pig on a cold engine required holding the starter switch for 60 seconds to even get an indication she would kick over... :blink: No joke! Richard also stated this thing had no power.... Had a nasty little ticking sound that turned out to be a missing vacuum cap...

We were going in for a head gasket(s)/O-ring change (nasty oil leak), valve clearances and carb adjust sync. To start with....

Combustion Chambers: Caked with dry carbon build up.... Shit, this crap was 1-2mm thick.... :blink:
scraped and cleaned... Same with the piston domes... Miracle this thing even sparked at all....

Timing chain was off one pin... Ok, so yeah that would effect power... :S
Adjusted valve clearances (3 intakes didn't have the right size so going back in), 3 intakes still tight... buckets do rotate thankfully...

Carbs...
All 4 pilots where anywhere from 3/4 turn to 4 turns out.... :pinch:
Set all 4 at 2.5 turns out... Will get back to these adjustments after reviewing new plug conditions and reported operations.

Sync (Morgan ):... Holly crapola, #1 was at 40cmHg.... 2, 3 & 4 @ 0cmHg... :pinch: :whistle:
OK, once figured out the syncing on these carbs, all 4 @ 18-20cmHg... Rise and fall in unison w/in 2cmHg.... All good!

Found one missing Vacuum cap missing carb #2. RTV in rubber hose piece until cap can be obtained, all better.

Next morning, Re-torque engine bolts/nuts....
Pull choke, she started in ~ 5 seconds, purrered like a kitten.

Richards ride comment.... Whoa, a whole new bike.... Not to mention the shit-eating-grin on his face....


Sorry for the long story :blush: but I don't see any mentioning of a carb sync here, maybe my old eyes missed it... Might want to take a look at that as well for it made a HUGE difference in Richards police special...

OMR

Old Man Rock wrote: I don't see any mentioning of a carb sync here, maybe my old eyes missed it... Might want to take a look at that as well for it made a HUGE difference in Richards police special...

OMR

I had the carbs synced and the valves adjusted about 1,500 miles ago. It runs OK otherwise but your point is well taken. It could use a tune-up.

Since I am going to tear the carbs down anyway I'll probably up the mains a bit. Anyone have an idea of how many sizes to go up? I understand a larger pilot is unavailable.

I decided to forego the Dynojet kit in favor of some larger mains. Since the problems I am having seem to exist at the zero to 1/4 throttle opening I thought I would try a larger pilot jet. I heard these are not available but when I emailed Z1 they sent me a link for BS30 pilots. Will these work in a BS34 carb?
TIA,
Jim

I bought jets for my 83 GPz 750 from them and they work fine, so they know what they are doing. $2 each plus shipping. Actually, it sounds like you need to shim your needles.
And you absolutely MUST call Z1 and speak to a human. They are very knowledgeable and helpful, and you can ask and answer questions directly.

before you do all this other stuff
Please verify that ALL carbs fuel level is correct (clear tube test)
then move on to other things if not right

just saying from the past