VM29 S/Bore Jetting?

[KEITH KRAUSE]

And you're sure all 4 cylinders are firing well? Sometimes a non-firing cylinder can make some strange sounds.
Any chance of fuel in the crankcase? Enough fuel in the oil can result in knocking. Oil level would be pretty high I'd say. Again, trying to eliminate basic issues first.

[srsupertrap]

And you're sure all 4 cylinders are firing well? Sometimes a non-firing cylinder can make some strange sounds.
Any chance of fuel in the crankcase? Enough fuel in the oil can result in knocking. Oil level would be pretty high I'd say. Again, trying to eliminate basic issues first.

Last Saturday I changed the oil after I had it running in the garage for about ten minutes, the oil level was normal and there was no signs of metal shavings in the oil pan as I mentioned earlier. The only thing I touched mechanically over the winter was R&R the clutch hub with the welded Falicon Hub. Last night based on rapidray's sugesstion I pulled the clutch cover and inspected the clutch hub nut. The nut was still tight & torqued. I removed the clutch hub so I could visually examine the two crank throws, no signs of debris. Looked good as the rest of the clutch components so I retorqued everything and reassembled.

I still want to test the oil pump output before embarking on 49er's modification for Cam End Play which is posted on basscliff's website. Essentially 49er states the cams are floating side to side along their axis and the low rpm knock is caused when the cam thrust ring makes contact with the side of lower cam bearing journal. Sound like the same noise I now have.

A VM & DJ Main Jetting Note: I was always wondering about the cross reference between VM & DJ Mains so I measured several VM Main jets with a calibrated Pin Gage Set (Minus series). I posted this in a earlier thread but made a typo; I wrote down a DJ 130 when I actually meant DJ 138. So take a look. Go means you can slip a pin gage thru the inside diameter with no resistance or binding

DJ 138 = .054" Go
DJ 142 = .055" Go

VM 117.5 = .046" Go
VM 120 = .047 Go
VM 122.5 = .048 Go
VM 127.5 = .050 Go

The VM Main are drilled in .001" increments and the same applies to the two DJ mains.

[49er]

Last Saturday I changed the oil after I had it running in the garage for about ten minutes, the oil level was normal and there was no signs of metal shavings in the oil pan as I mentioned earlier. The only thing I touched mechanically over the winter was R&R the clutch hub with the welded Falicon Hub. Last night based on rapidray's sugesstion I pulled the clutch cover and inspected the clutch hub nut. The nut was still tight & torqued. I removed the clutch hub so I could visually examine the two crank throws, no signs of debris. Looked good as the rest of the clutch components so I retorqued everything and reassembled.

I still want to test the oil pump output before embarking on 49er's modification for Cam End Play which is posted on basscliff's website. Essentially 49er states the cams are floating side to side along their axis and the low rpm knock is caused when the cam thrust ring makes contact with the side of lower cam bearing journal. Sound like the same noise I now have.

A VM & DJ Main Jetting Note: I was always wondering about the cross reference between VM & DJ Mains so I measured several VM Main jets with a calibrated Pin Gage Set (Minus series). I posted this in a earlier thread but made a typo; I wrote down a DJ 130 when I actually meant DJ 138. So take a look. Go means you can slip a pin gage thru the inside diameter with no resistance or binding

DJ 138 = .054" Go
DJ 142 = .055" Go

VM 117.5 = .046" Go
VM 120 = .047 Go
VM 122.5 = .048 Go
VM 127.5 = .050 Go

The VM Main are drilled in .001" increments and the same applies to the two DJ mains.

Thanks for the confirmation on the VM jet sizes. The numbers actually mimic the size in millimetres, i.e, the VM 127.5 measures 1.275 mm, which in turn equates to .050". I've never had the need to measure any DJ jets as a comparison!

[Don-lo]

Supertrap,

First off, nice looking bike! I had a 1000E painted up a lighter shade of your blue, but no cal-fab swingarm, lol. You state there are slotted cam gears, but didn't state the degree(s) the cams are at. Also, what formula did you use to degree the cams? I ask because this is one of the most important elements in getting a GS to idle and transition up.
Also, GS "knocks" are common and often harmless. A small hydraulic lock-up in a high compression engine could do some damage, though. I would check each cylinder by pulling each plug wire and grounding an extra spark plug to the head, then start and run the bike to see if the sound changes when there is no spark to that cylinder. A bad rod bearing or broken piston skirt (I had one of those) will be less noisy without combustion. I have also seen debris wedged into the big gears (crankshaft/clutch hub) that makes a definite knocking noise. Good luck and let us know what you find.

[srsupertrap]

6/24 Findings

Finally got back to diagnosing last night. First, thanks for all the comments and interest. I warmed up the GS and got it up to operating temperature and as expected the knock returned @ idle up to 2000 rpm. I tested the oil pressure with a new 15 psi VDO oil pressure gauge; the oil pressure was significantly higher when I started but progressively dropped since it was 85 F outside and I recorded 4 psi @ 3000 rpm. The Factory Specification for the GS1000 oil pump is: 1.4 psi < Oil Pump Output < 7.2 psi @ 3000 rpm. Okay.

I have checked and ruled out the following items: 1) Static Timing and # links between cam sprockets 2) I verified the timing with timing light. 3) Cam Chain tensioner operates per the Factory Manual test were you first rotate the crank backwards while backing off the Cam Chain tensioner spring. Next rotate the crank clockwise and verify the tensioner rotates inwards taking up the cam chain slack. 4) Adjusted the #2 intake valve shim to be tighter since the knock is pronounced in that area; all other valve lash okay 5) Per Don-lo’s suggestion, I checked each cylinder by pulling each plug wire and grounding an extra spark plug to the head, then started and run the bike to see if the sound changes; I found no change in the knock location or sound. 6) Per KK suggestion, the spark at all 4 cylinders is excellent thanks in part to the Coil Relay Modification. 7) The cam sprockets bolts were not loose nor had the slotted cam sprockets rotated CW. 8) Andrews 1S Cams are set to 108 C/L angle.

The knocking noise is still most pronounced by the Intake cam. To help determine the location of the sound I employed the long screwdriver method and found the loudest internal noise is actually produced by the cam chain but that isn’t a knocking sound. When I place the screwdriver against the cylinder head by the Intake cam I hear a cyclical knock which isn’t tappet related. So it appears 49er is correct. Next question has anyone performed 49er’s Cam End Float modification stateside and can they recommend a Machine Shop that has successfully performed the modification? My GS has 43.5 K miles.

members.dslextreme.com/users/storagecliff/images/cam_end_float_mod.pdf

Don-lo, the imron paint is twenty years old and the color is 87 IROC Blue. It's due to be repainted, the clear paint under the Gas Cap is lifting. The OEM black paint took a dive while I was stationed at sunny Holloman AFB, NM.

[Don-lo]

Yeah, sounds like there are no damaged rod components, so looks to be the cam end float. The mod looks serious enough to leave in the hands of a machinist. If you do it, let us know how much it costs, please.

[srsupertrap]

Back on the Road this weekend

With the help of 49er, a Machinist at work & $200 I have completed the Cam End Float Modification and hopefully that will eliminate that knocking noise. While I was awaiting parts, I refurbished & repainted my original Master Cylinder as well. When I installed the modified cam caps & half moon washers I degreed the Andrews cams to 108 C/L with zero lash.

Since there has been a lot of discussions on oil coolers I took a couple of pictures last night of my new Parker lines and where I hid the thermostat. The Lockhart BP-180 is located between the frame tube aft of the valve cover oil vent hole.



I like the look of S/S lines but the Parker Push Lok hose is much more flexible and the last set lasted 18 years. I also can also easily remove the valve cover.



I have bumped the VM 29 S/B main to 127.5 from 125 . My fuel filter has also been bent like Nessism and other have noticied.

[49er]

Brand new bike.

Man that's a sweet looking setup. It's a shame that you have to ride it and get it all dirty!

One other thing, how are you going to fit up your airbox with all that new plumbing around those carbs?

Enjoy your new mods.

[renobruce]

Holy crap! Nice looking engine! Great work. I've been watching this thread regarding your carb set-up. Since we are at similar altitudes, you're my Guinea pig for when I put the 29's on my project!

[renobruce]

Where did you find your cam cover bolts? Are those chrome flange heads?

[srsupertrap]

Where did you find your cam cover bolts? Are those chrome flange heads?

Yes they are. They are Suzuki's new style cam cover bolts and I personally like the flange better than the original bolt head style.

Man that's a sweet looking setup. It's a shame that you have to ride it and get it all dirty!

One other thing, how are you going to fit up your airbox with all that new plumbing around those carbs?

Enjoy your new mods.

49er, I get those clean comments a lot. I cannot help it. I wish I could post the original Polaroids (sic) of this thing with the Shoei FM-2 fairing & highway bars!

[49er]

Have you got this quiet shinny thing correctly jetted and running yet? Or has winter slowed your enthusiasim/progress?

[srsupertrap]

Have you got this quiet shinny thing correctly jetted and running yet? Or has winter slowed your enthusiasim/progress?

The answer is yes but you side tracked me on that cam end float modification. Like so many other threads I never crossed the T's & dotted the I's. So this VM29 setup works seamlessly on my GS1000/1085 at altitude 5150 feet.

Mikuni VM29 S/B Configuration (12/05/08)
Pilot: 22.5
Needle: 5DL31-4
Main: 127.5
Air Screw: 1/2 - 1 turn out
Throttle Valve Cut Away: 2.0

79 GS1000: Wiseco 1085 10.25cr
Andrews S-1 & H/D valve springs
Dyna 3 Ohm Coils, Dyna III Ignition & Accel wires
Falicon welded & balanced clutch basket
K&N Pods
Supertrapp 4into1 w 20 discs

Notes:
1) Most VM29 were equipped with 1.5 T/V Cuts and it's suprising how close my setup is to Sudco's 2.0 T/V recommendation.

2) To get that accurate main jet reading, mark your kill switch & throttle with alignement marks of your choice that positively indicate 3/4 opening. Be careful out there because even in 4th gear you will quickly find that needle is swinging way past 100 mph.

[renobruce]

The answer is yes but you side tracked me on that cam end float modification. Like so many other threads I never crossed the T's & dotted the I's. So this VM29 setup works seamlessly on my GS1000/1085 at altitude 5150 feet.

Mikuni VM29 S/B Configuration (12/05/08)
Pilot: 22.5
Needle: 5DL31-4
Main: 127.5
Air Screw: 1/2 - 1 turn out
Throttle Valve Cut Away: 2.0

79 GS1000: Wiseco 1085 10.25cr
Andrews S-1 & H/D valve springs
Dyna 3 Ohm Coils, Dyna III Ignition & Accel wires
Falicon welded & balanced clutch basket
K&N Pods
Supertrapp 4into1 w 20 discs

Notes:
1) Most VM29 were equipped with 1.5 T/V Cuts and it's suprising how close my setup is to Sudco's 2.0 T/V recommendation.

2) To get that accurate main jet reading, mark your kill switch & throttle with alignement marks of your choice that positively indicate 3/4 opening. Be careful out there because even in 4th gear you will quickly find that needle is swinging way past 100 mph.

Thanks for the set-up info!! I'm at 5210 ft. with basically the same mods on my project. The only difference I see is that my head is ported and I will have different cams. Where are your needle clips?

[srsupertrap]

Thanks for the set-up info!! I'm at 5210 ft. with basically the same mods on my project. The only difference I see is that my head is ported and I will have different cams. Where are your needle clips?

I have got the needle clips set at #4 with the following needle orientation: #1 is at the top & #5 is closest to the tip. Hope that helps.