Last Shout - Posted by: Grumpy225 - Sunday, 25 August 2013 15:27
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Kickstart locking up - issue with gear float?

 
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mystery
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PostPosted: Sun May 04, 2008 2:55 am    Post subject: Kickstart locking up - issue with gear float? Reply with quote

Last week I broke the kickstart shaft on my Series 3 1965 Li Special (deanspeed 190 kit) and ordered the replacement from Alex at Casa. I rebuilt this engine from the ground up last winter and it was running great all last year. I put the new shaft in the chain case today and started to put it all back together and found that pretty much every other kick will lock the kickstart. To the point where it felt I could literally stand on the lever.

When I assembled the engine last year, i needed to put a new first gear on it b/c the previous owner had chipped off most of the teeth that the kickstart piston connects with. At that time I checked the float and it was fine. Today I saw that I was able to get a .660mm feeler gauge in between the shim and endplate where the sticky guide says you should only get up to .3mm in there.



Clearly i need to reshim the gears but would this cause the kickstart to lock up like this? There were NO problems till the old one broke. I attest that to being a 43 year old part that had a high compression top end thrust on it at the end of its life. no catastrophes were involved in its breaking.

The only change made was a new Casa Lambretta kickstart shaft and kickstart piston. I did have to mod the shaft with an angle grinder to keep it from rubbing on the clutch and sand the inside of the shaft where the piston sits to keep it from sticking. Is there another mod that I missed?

Any suggestions would be appreciated. Its getting warm and I really dont want to have to break my P200 out...
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bayarealam
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PostPosted: Sun May 04, 2008 4:17 am    Post subject: Reply with quote

I doubt it has anything to do with the endplate shim....my gut says that the kickstart shaft is getting hung on the guide...you can adjust that guide to suit.
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mystery
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PostPosted: Sun May 04, 2008 4:54 am    Post subject: Reply with quote

Ill try adjusting the guide tomorrow afternoon. Even when the kickstart doesnt hang up, the kickstart piston doesnt catch till the kickstart lever is half way down, Ill see if I can drop the guide some to give it some more throw...
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Lambrettayeroc
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Location: Ottawa, Ontario Canada

PostPosted: Sun May 04, 2008 10:19 pm    Post subject: Reply with quote

The only kickstart shafts available new are thicker GP later types.
These need to be installed after the engine case cover has been machined down a couple of mm to allow for the thinker shaft.
I bought a special tool form MB development when I went there last summer to do just this job.
It fits into the brass bushing and then shaves off the cases just enough to take off the amount you need removed.

I will look at MB's site to see if they have the tool for sale
Here is is...
http://www.lambrettaspares.com/spareparts/Engine-tools/Kickstart-modification-tool,-MRB/MRB0647.html

It is likely that your shaft is driving itself into the first gear and causing it to jam up because it is too close to accommodate the thicker shaft.

It is likely you will need to buy another shaft if you have "modified" it with an angle grinder to fit.
They were made thicker about the time of the SX 200 because they were braking from the stress related to the higher cc engines.


In the old Lambreta testament... on page E 24 there is a specific section describing this. (See home workshop manual)

I never though I would be leading people to the home workshop manual after Sticky's book but...
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mystery
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PostPosted: Mon May 05, 2008 1:11 am    Post subject: Reply with quote

When I bought the shaft from Casa, Jon and I spoke at length about the work that was needed for this to work in my li. I bought a premod shaft

and used the angle grinder to reproduce this cut in my existing kickstart shaft:


(this is a photo of the one I broke)

From what he told me, it was either or. Either you grind it like I did, or you cut your case like you did. The reason for doing both (either) was so that the base of the shaft didnt rub on the clutch. Cutting the cases (so he told me) was better for race engines with lots of compression.

What part are you saying is thicker? I did a side by side comparison and didnt see any differences other than one was broken and one wasnt. Nothing seemed any bigger or smaller other than the shaft that passed through the case on the new one was a mm or 2 shorter.

I dont have the old home workshop manual, I would be interested in reading the part you are talking about. Ill have to see if I can dig one up from the other guys in the club.
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Lambrettayeroc
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PostPosted: Mon May 05, 2008 2:11 pm    Post subject: Reply with quote

Casa may be producing new pre mod shafts... I know they were not about a year and a half ago.

From the home workshop manual... Page E24

Kickstarter modification, Li Series III. Towards the end of the production run of the SX models, the flange on the kickstarted shaft was made 2mm thicker, and the housing in the transmission cover was altered to fit. The revised part is fitted frm the following engine numbers onwards.
Li150, SX 150 - 768 530 SX200- 847 625
and as only this latest type of shaft is now supplied as a spare part, the cover must be modified or a post-modificatio cover fitted. The part Nos. are: Shaft 19530502, and cover 19510510.
A special workshop tool No. 79187 is available (price 2.15.0.) to cut 2mm form the inner end of the kick starter housing. In addition, the radius on the inner edge of the bush must be reformed. A leaflet, Technical Dept. Newletter No. 13-68, is available whick shows the tool in operation and gives details of the relevant part numbers etc.

Kickstarted Modifiaction J range
The same modification as that described above has been applied to the J range, starting with engine No. 16063 (Starstream), and in addition a new plunger retaining screw and cam is used.

Kiskstart shaft location, all models
Apart from the flange modification noted above, a;; Li series III kick starter shafts dispensed with the circlip for end wise location, and the pedal clamp bolt does this job. Additional security is given by machining a groove in the serrations on the shaft, so that the bolt is inset in this. A series III shaft can be fitted to earlier Li models, but it must be remembered that the pedal clamp bolt must be kept tight at all times.


Now...
the broken shaft from my SX 200 is a thinner shaft than the GP type and cracked from the stress...
The new shafts are thicker. Precisely where your have ground down on yours.
If I can find my old shaft and a newer thicker one to compare I will take some photos of the both of them... Patience. please ... I have a lot to dig through.

PS: Nice mudflap! : )
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LambrettaWorks
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PostPosted: Mon May 05, 2008 3:20 pm    Post subject: Reply with quote

No, actually the problem lies with the little raised piece in the middle of the shaft that needs to be shaved down. I had that same problem, and presto, i feex et fast, ok!
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mystery
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PostPosted: Mon May 05, 2008 3:29 pm    Post subject: Reply with quote

which raised piece?

A, B or both?

How much grinding are we talking about here? What is it catching on?

Im a bit wary about grinding off supports for a high stress piece...
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mystery
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PostPosted: Tue May 06, 2008 4:24 am    Post subject: Reply with quote

OK its fixed! At least this part anyway. the resolution was 2 part. 1. the brass bushing was pushing out so the kickstart was riding higher than it should and I needed to take more meat off the flange and indeed off the nipple like lambrettaworks suggested. When I took it off the last time, there was shaved metal on the flange and the edge of the clutch was all rough. Ground it down and VOILA no more catching.

THanks for all the help. Now on to fixing the float...
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