Can you rechrome VM29 Throttle Valves?

[srsupertrap]

Dumb idea or has anyone successfully rechromed their Smoothbore throttle valves? The chrome plater would have maintain the original outside diameter.

Let me know, Sudco supplies new ones but they set you back almost $250 for a set of four.

 

[dardoonk]

To re-chrome, they'd probably have to remove the existing chrome first. The trick would be getting the thickness of the new chrome correct. Are yours worn that bad? You might call Jeff @ Z1 - he has a few old parts for these.

 

[KEITH KRAUSE]

Not saying it can't be done, but the new chrome thickness would have to be exact. Any changes to thickness or even the plating procedure could cause problems.
I'd have to say buy new ones if you can. Peace of mind.

 

[TheCafeKid]

Im no metalurgist either, but i would have to go with Keith on this one. I dunno if its possible to get them exact, and even if there was, how would you know untill it caused problems?

 

[srsupertrap]

Pic Inserted

Pic Inserted

To re-chrome, they'd probably have to remove the existing chrome first. The trick would be getting the thickness of the new chrome correct. Are yours worn that bad? You might call Jeff @ Z1 - he has a few old parts for these.

I actually purchased this used set of four 2.0 Slides from Z-1, at a bargain price and I agreed to buy them. What I found is 3 of the 4 slides are worn down to the brass and I certainly don't want to run them and ruin my perfect unmarked bores.

It looks like the Slide is machined from bar stock so if the set were emersed in the deplatting tank I believe they wouldn't come apart at the seams. The Platter would have to be very exact to build up the chrome back to the 33.45 to 33.50mm. I am guessing at least $100. I am with everyone on this one.

Here is a "good one" . . . .

Thanks

 

[Calvin Blackmore]

I know a guy that had a transmission shaft in he 74 XKE hard chromed back to tolerance.

He said it was very expensive and that he would not have had it done but for the lack of any replacement part.

So it can be done but the cost benefit analysis might steer you towards new parts.

 

[srsupertrap]

Re: Before & After Pics

Re: Before & After Pics

Well despite sound advice I went ahead and replated my damaged VM29 2.0 Slides with Electroless Nickel to avoid having to purchase a new set from Sudco for $265. The EN filled in the obtuse scratches but the slides had to be buffed in areas which left a duller finish. This is a cosmetic issue and not a functional one but they could certainly look prettier. EN Rockwell hardness is equivalent to chrome.

The plater I used maintained the critical 33.45mm OD :-D but the process had a steep learning curve and took over a month and he had to strip them twice. There more to these Slides than meet the eye: the inner cylinder is machined but the outer Slide is pressed on and held in place by silver solder. The Slide slot is then milled in.

BEFORE​

AFTER​

 

[Calvin Blackmore]

so this begs the question how much money did you save?

 

[srsupertrap]

Well, I had a contact at the Plating Shop and the guy got interested in the Project because it was different than plating commercial frames etc. So he did me a favor and saved me quite a bit. Most Plating Shops probably wouldn't accept the job because of the unknown variables but were there is a will there is a way.

Last night, I reassembled the VM29 Smoothbores with the replated Throttle Valves and everything is moving freely.

 

[Calvin Blackmore]

Excellent that you overcame any naysayers.

It is a good bit of information to have especially for instances of folks with Bikes or other vehicles for which no replacement part exists at any price.

 

[Road_Clam]

I have never seen a slide wear out like in the above pic. So that being said what does the bores of the carbs look like? Chrome is WAY harder than aluminum.

 

[srsupertrap]

Re: Now GS1000 & VM29 only runs on Choke

Re: Now GS1000 & VM29 only runs on Choke

I installed the replated VM 29 2.0 Slides started up the GS1000 last night with the hope of synching the Carbs and found the GS only runs with a combination of half Choke & throttle and won't idle even when warm. The half choking fouled one of the plugs and that cylinder was cold so I replaced the plug and still no better. The only changes made to the previously synched, start right up & idle VM 29 S/B was I replaced the 1.5 Slides with 2.0 replated Slides. The VM 29 Slides are machined to precise tolerances and shouldn't upset the carb synchronization or so I thought. :-s I was able to get the Twin Balance Carb Syncher on Cyl 1 & 4 and they were close.

I will be pulling the Carbs of tonight; what's your opinion on the next step. Bench synch with a Gage Pins slid under the throttle valves or I was wondering since the 2.0 Slide Cutaway allows more air than the 1.5 Slide they replaced is the Pilot jet now to small to let my GS1000 idle? Sudco recommends a Pilot Jet of 25 but that's at sea level (See below) The intake boots & O-rings are okay.

Mikuni VM29 S/B Configuration:
Pilot: 15
Needle: 5DL31-2
Main: 127.5
Air Screw: 1 turn out

79 GS1000: Wiseco 1085 10.25cr Compression good
Andrews S-1
K&N Pods
Supertrapp 4 into 1

Altitude: Denver, CO. 5150 Feet

 

[KEITH KRAUSE]

I installed the replated VM 29 2.0 Slides started up the GS1000 last night with the hope of synching the Carbs and found the GS only runs with a combination of half Choke & throttle and won't idle even when warm. The half choking fouled one of the plugs and that cylinder was cold so I replaced the plug and still no better. The only changes made to the previously synched, start right up & idle VM 29 S/B was I replaced the 1.5 Slides with 2.0 replated Slides. The VM 29 Slides are machined to precise tolerances and shouldn't upset the carb synchronization or so I thought. :-s I was able to get the Twin Balance Carb Syncher on Cyl 1 & 4 and they were close.

I will be pulling the Carbs of tonight; what's your opinion on the next step. Bench synch with a Gage Pins slid under the throttle valves or I was wondering since the 2.0 Slide Cutaway allows more air than the 1.5 Slide they replaced is the Pilot jet now to small to let my GS1000 idle? Sudco recommends a Pilot Jet of 25 but that's at sea level (See below) The intake boots & O-rings are okay.

Mikuni VM29 S/B Configuration:
Pilot: 15
Needle: 5DL31-2
Main: 127.5
Air Screw: 1 turn out

79 GS1000: Wiseco 1085 10.25cr Compression good
Andrews S-1
K&N Pods
Supertrapp 4 into 1

Altitude: Denver, CO. 5150 Feet

The VM carbs must be re-synched anytime the slides are disturbed in any way.
There has been some difference of opinions over the years as to the correct slide/cut-away for the 1000 and Suzuki's in general. I always thought the 1.5's should be used but others say I'm wrong and the 2.0's are right?
So you say the only change is the slides and you fouled a plug? Is that based on the cylinder being cold or is the plug actually soot/carbon fouled? With no other changes since it ran better with the other slides, your leaner slides wouldn't figure to foul a plug, however, the synch could be thrown way off and that could factor in.
I never have used a drill bit or whatever to synch slides. I use my eyes to set them uniformly at their lowest point and that's always been good enough for initial start up and then once warmed up I set the side air screws using the highest rpm method and then I hook up the vacuum tool and final synch.
As for what to do next, I'm off for work so I'll have to come back later if you still need help. I don't know if I'll be able to help but I can try.
The cut-away's job is to regulate mixture at the throttle position between the pilot jet and jet needle circuits. It shouldn't cause the bike to truly foul a plug (dark/sooty) because, when the slides are at a position where you would be at true idle, the cut-away's aren't regulating mixture.
To put it simply, I think you're sucking too much air now and I really don't know if you can adjust for it. The air jet could factor in as could a poor synch and/or poor air screw adjustment.
I'll try to help later.