• Ciao Guest - You’ve landed at the ultimate Guzzi site. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER - Use the CONTACT above if you need help. New to the forum? For all new members, we require ONE post in the Introductions section at the bottom, in order to post in most of the other sections. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have, have likely been already answered. DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back in and reply within 24 hours, or your post will be deleted. Note there's decades of heavily experienced Guzzi professionals on this site, all whom happily give endless amounts of their VALUABLE time for free; BE COURTEOUS AND RESPECTFUL!
  • There is ZERO tolerance on personal attacks and ANY HYPERLINKS to PRODUCT(S) or other competing website(s), including personal pages, social media or other Forums. This ALSO INCLUDES ECU DIAGnostic software, questions and mapping. We work very hard to offer commercially supported products and to keep info relevant here. First offense is a note, second is a warning, third time will get you banned from the site. We don't have the time to chase repeat (and ignorant) offenders. This is NOT a social media platform; It's an ad-free, privately funded website, in small help with user donations. Be sure to see the GTM STORE link above; ALL product purchases help support the site, or you can upgrade your Forum profile or DONATE via the link above.
  • Be sure to see the GTM STORE link also above for our 700+ product inventory, including OEM parts and many of our 100% Made-in-SoCal-USA GTM products and engine kits. In SoCal? Click the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work, and don't miss our GT MotoCycles® (not) art on the BUILDS tab above. WE'RE HERE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED - DO NOT EMAIL AND ASK QUESTIONS OR ASK TO CALL YOU.
  • Like the new V100, GuzziTech is full throttle into the future! We're now running on an all-new server and we've updated our Forum software. The visual differences are obvious, but hopefully you'll notice the super-fast speed. If you notice any glitches or have any issues, please post on the Site Support section at the bottom. If you haven't yet, please upgrade your account which is covered in the Site Support section or via the DONATE tab above, which gives you full site access including the DOWNLOADS section. We really appreciate every $ and your support to keep this site ad-free. Create an account, sign in, upgrade your account, and enjoy. See you on the road in 2024.

Throttle shaft wear

Nordicnorm

Cruisin' Guzzisti
GT Famiglia
Joined
May 12, 2011
Messages
382
Location
Vancouver Island BC
During my recent replacement of my TPS, I discovered play in the throttle shafts. The bike ('01 Jackal, 97K km) runs better than ever, but I can actually move the top of the throttle shafts slightly with the engine running.
What wears?
The shaft, or is there a replaceable bushing in the throttle body?
It can only get worse, and since I park the bike for the summer (Breva time!) it seems like a worth while project, as I assume it could be a source of unwanted air and future headaches.
Any input, as always, will be appreciated.
 
This also occurs on BMWs. I don't know of an off the shelf replacement bushing. A good machine shop should be able to make appropriately sized bushings.
 
No parts are available for the throttle bodies through Guzzi at all, so as John says above, custom work time... or of course if you find anything, please let us know.
My Jackal is stalled out at ~170k miles, only because my Stelvio is my main mode of two-wheel transport these days.
I'll never get rid of my (very first Guzzi) Jackal. In fact, I am planning a restoration of sorts end of this year.
 
Hmmmm....does not appear to be a common problem (3xmy mileage on Todd's bike). So I took a second look. Maybe not as bad as I thought at first. I will remove the arms attached to the throttle shafts to gain access and see if I can get some good hi temp lube in there. That could also seal the shaft/bushing area from drawing false air.
01 Jackal Rearsets SB bars touring seat tach all day comfort
The love of old Jackals; after dealing with all the common problems of an early B-11, I consider it the most brilliant bike I have owned. However, if it came down to parting with one of the two, it would be a very tough choice. There is something I would call "Guzzi Goodness" in the old Blackjack that is hard to define. Wheels are wheels, and frames are frames, but there is something about that motor....
I will try to attach a picture, hoping it can be transferred/attached to my Cali registration on this page.
Rear sets, SB bars, touring seat, tach, all day comfort.
 
Interesting: the RH shaft is pretty tight. It has a seal on top of the shaft to protect the bushing. On the LH side, the seal is missing and there is more wear/play. With great patience I have been able to force hi-temp silicone based lube (used on brake assemblies) into the bushings.
Shopping for seals tomorrow (8x11x2mm), if not I will use O-rings.
Stay tuned.
 
I have previously made brass bushes from thin wall brass tube bought from a model shop . In these instance's ( wbeber 32/36dgav and a holley 390 4bbl) the inside dia was a perfect fit over the shaft . On one carb I had to glue ( liquid steel ) the bush in , using the throttle shaft as a guide/ mandrel as the bush was just a finger push fit , the other carb , I made a better job of drilling the bore out to suit the bush OD ( used more patience ) and attempting to push the bush in only resulted in a 11/32" dia hole in the end of my thumb.
To drill the hole bigger I tapped the next size bigger drill right thru both sides of the carb , clamped the stub end of the drill in the vice and rotated the whole carb . By swapping between metric and imp sizes I was able to "ream" the hole without taking to bigger swipe , and have suffered no alignment issues . The brass tube was a few bucks and they had heaps of size combo's :)
 
After contacting the usual sources, MG Cycle, Harpers, Moto International, Cycle Garden. I had luck sourcing a BSN left footpeg mount for my '96 Lemans, and a used rear wheel spacer (inner) for my '96 Sport from Gutsibits UK: http://www.gutsibits.co.uk

The folks at Gutsibits were very helpful, very responsive and took the time to take and send pictures and dimensions of the spacer. A little expensive after shipping and currency exchange, but when it's the last known available spacer for your sons M/C mechanic school project bike...

Nordic Norm, I'm not saying they will have wear parts for your particular situation, but there are more Guzzis in Europe :)
 
McTool and Blackbird, thank you. Good information for the future.
Eventually it may come to that
I think I may have caught this before it is critical wear. Surely MG does not make throttle bodies, so the seal was left out at Weber Marelli. Sloppy.
I will make this part of my periodic maintenance. It only takes a few minutes to remove the arms from the throttle shafts to pick out the seals and lubricate.
The seal(s) appear to be 8x11x2mm. I could not source that size, but I have ordered up a set at 8x12x3mm. My theory is that I may be able to put them in "upside down" if they do not have steel insert in the outer part that pushes into the bore. There is no venturi in a f/i throttle body, but low pressure down stream from the throttle plate, so with no seal it will try to draw things (dirt) down along the shaft and dry out any lubrication. Hence the wear. That makes me think the seals should go in that way to begin with, as nothing is trying to push it's way up past the seal.
In the mean time some O-rings from the plumbing store seem to fit real well. They are 5/16 x 7/16" and measure approx. 7.6x11.3x1.8mm.
Forgive me if it does not convert correctly (caliper in hand), but they fill the space around the shaft, and below the washer capping it, quite nicely. With hi-temp lube, it should stay air-leak free (and wear free) for some time.
If I can make the seals work, I will post here.

Nothing I can think of on the bike moves as much as the throttle shafts with basically no lubrication.....
That hole in your thumb is a nice testament to your dedication:D
 
http://www.carburetion.com/diags/3236DGAVDiaginfo.asp
Have a look at this . The bush ( 20 ) is a plastic thing that is a snug sliding fit on the shaft , the spring (21) pushes that bush against the face of the carb body ..... so that if there is wear in the spindle bush in the carb body the plastic bush can move about with the spindle but is still against the face of the carb thus sealing both air and dirt out .... well better than nothing . It looks to me like with a bit of ingenuity this set up could reasonably easily be adapted to fit a lot of carbs / throttle bodies ) ... maybe :)
 
Seals did not fit. Steel reinforced, but I am good with the O-rings and lube. The left throttle needed the idle increased slightly after the work, so looks like air was leaking in before. The arms are a snug fit, so the balance was not disturbed above idle.
I intend to make this part of my maintenance, maybe with checking valve clearances, which is not too frequent.
 
Back
Top