GS1000 8 valve with 3000 rpm problem

[PeterBoomhut]

Hi Peter, it's been a while !

Those igniters are sturdy but can fail, causing strange issues.

Have you checked the connectors are clean and it gets good 12v and ground ?

Hi Rijk, how are you doing? GT750 already ready?
The plugs of the connecters are 6.5mm sliding plugs, there is little to clean, and usually that makes good contact. What I do wonder is whether a GS1100 ignition box works on a 1000. I am also busy cleaning a 3rd set of carburettors, with all new O-rings and very good checking that all channels are good. Ie Jets and Idle port, (opening near the block after the throttle) and the Transfer Port (opening under the throttle)

[Rijko]

GT750.jpg

GT is ongoing. Mostly done, need original front discs (non perforated).
I am working on the rear shocks and have an original seat looking
like new. Some other details.

Sounds like a good plan to try another ignition on the GS1000.
Just to confirm your setup works and is not broken.
Maybe Jordy has one or can borrow one from Frank ?

[Rijko]

GS1000.jpg

Started working on this GS1000 again after a loooong time

[PeterBoomhut]

GT is ongoing. Mostly done, need original front discs (non perforated).
I am working on the rear shocks and have an original seat looking
like new. Some other details.

Very nice, we should meet again @Franks Place

Sounds like a good plan to try another ignition on the GS1000.
Just to confirm your setup works and is not broken.
Maybe Jordy has one or can borrow one from Frank ?

We have tested the bike with another CDI and pick-ups, same results!
When we set the idle speed to normal values 1200RPM (coming from below 800RPM) and we give some throttle, the machine does not fall normally from 3000 RPM

We now suspect either a bent valve or a leak in the manifold. Although a curved valve is a question mark with leak values of: 5% -3% -3% -2%.
But 1 or 2 sputters back into the inlet, so there is still something going on in the head

[PeterBoomhut]

[ATTACH=CONFIG]61470[/ATTACH]

Started working on this GS1000 again after a loooong time

Do you want it to come original?

[Rijko]

no, this is not an S but a regular GS1000.
Like the look as it is.

New Tarozzi rearset on old Raask hangers.
Rebuilt Marzochhi rear shocks.
New stainless steel Delkevic exhaust.
New Dyna S and 3 Ohm coils.
New tires on freshly powdercoated 18 inch Slabby wheels with new bearings,
Sonic front fork springs.
Will probably upgrade the front brakes to Lockheeds.

Seat pan made to fit the frame, next up will be seat upholstering.
I will build all new electrics, from Caltric stator to SH775 RR and will
probably use the M-Unit i have for that, too.

The black tank is just used for fitting the seat pan, i have a red one.
Here's a pic from earlier

red.jpg

[Rijko]

Slow return from higher rpm and spitting back usually means really lean, so a manifold leak may very well be the issue.

[allojohn]

OK, I'm going to ask the stupid question so don't smack me... most people use clear tubing for the gas line and vacuum line. In the photo you have a clear line going to carb #2 and black line connected to carb #3. Are you using the line from # 2 carb for vacuum? It should be on carb #3.

[Big T]

John, he's already said he capped the vacuum port on #3. Clear lines to vents as needed

[allojohn]

Thanks Big T, I just thought it looked weird even though he's deep into a more serious issue...