Please, help me on sorting an Alpino problem

O

ossaf3

New member
Dear friends,
I am just new on the forum, I'm a Spanish guy who has since one year back an Alpino 500 bike, I bought it from a guy who keep it in a reasonable good external look but with no so good health inside.
I have a strange problem with the way that the bike runs, it starts well and after around a minute with the choke on she idles quite happily, the problem is that you can not increase the speed above 110-120 Km/hr. It seems as the gearbox was in need of another 6 gears!, there is no appreciable difference on speed from 5Th to 6Th gear, and you can insert all like in a motocrosser bike, in 100 meters all are in!
The pinion and rear sprocket are the standard ones.
It pulls well from the bottom, at least that is my feeling, and the tacho needle goes up very quick, perhaps too quick...
I have checked with the previous owner, as I was in doubt that perhaps he had change the gears for the Atlas ones (thinking that they could have a shorter ratio), but he has confirmed that the gears were the Alpino standard ones, he has told me that he opened the engine to clean the inside and just replacing the chain slider. 
Being sure that it was not a solution, but not knowing what else to do, I have tried with the main jet going from 115 to 130, but nothing positive happens.
Also I tried with a 2 into 1 (Montjuic style) pipe, but out of a tremendous and pleasant noise no speed improvement at all.
I do not need a speed record breaker but I understand that she should be able to run at 150-160 easily.
Please, I need your help to try to find the origin of my problem.
Any idea?
Please, here around there are no many people with enough mechanical knowledge about these bikes, so your inputs will be welcome.
By the way, sorry for my poor English.
Best regards,
OssaF3 (I?aki)
 
Por los s?ntomas que cuentas, has pensado en el embrague?

Qu? aceite tienes puesto en el motor? ten en cuenta la edad de estos motores, no le van nada bien los nuevos sint?ticos; nada c?mo un buen aceite mineral 20 W 40.

De todas formas aqu? encontrar?s muchos participantes con un gran nivel t?cnico que sin duda te podr?n ayudar.


Bienvenido al foro I?aki.  ;)




 
Thanks for the warm welcome paparracas (I will keep on English to make everyone easier to follow my post, OK?) and also for your comments, for the oil I am using a mineral Bel-Ray 20w50, concerning the clutch, I do not know..., I am not sure it could be the problem, it seems to be OK, and has no symptom to slip on the low gears. I will give a little more play on the pushing lever just in case...
Regards,
OssaF3 (I?aki)
 
Sounds a bit like the valve timing is out, especially if re-jetting has no effect at all.

Remove the cam cover and turn the engine till the markings on the cam chain wheels show up, they both should align vertically with the marks on the adjacent bearing housings when the RH(!) cylinder is at TDC.  Main jets can remain at 115 iIrc.

All other Lav engines are timed to the LH cylinder (well, the 180 triples and 750 twins don't particularly care if left or right are used :D), the 500 differs in this respect. 

piet
 
Hi, I am based in Madrid, pero hablo solo un pocito espa?ol.  ???
When you hit 120 kph do the revs continue to rise? (slipping clutch), or does it just not want to rev any higher (timing, air flow)
What revs is it doing at 120 kph? This will tell us if the gearing is wrong.
What air fitration does it have? Standard, nothing, individual pods?
 
Dear Piet and Grant,
Thanks for your support, that as I could imagine will give me quite a lot of tinkering with the Alpino.
Some months back I checked the valve timing following the factory manual, and apparently it was right (but I will double check, just in case!). About the clutch, it holds the bike at the traffic lights changing momentum very well and also permits an easy neutral selection (that most of the times I tried to obtain while the bike is still on moving), the tacho needle, at least in my bike, is quite jumpy, being in the area of 6-7.000 r.p.m at 100-120 Km/hr, but it can rise easily 8-9.000 r.p.m just turning the gas command. The feeling when riding is like if it was not more power once crossed the 110-120 km/hr point, there is a clear lack of any change from that speed onwards, even riding down a serious mountain road there is no speed increase, it seems that the engine has been fixed by the Spanish traffic police just to prevent me on crossing the 120 km/hr limit :D!!!!!!
I removed the paper filter as it was in a very poor condition, and I am checking around to find some apropiate cone filters (not easy due to the short distance to the tank bottom). I changed the perished rubber manifolds by similar ones that are connected in the standard way to the filter box, I sprayed some oil inside the filter box to help with the dust retention.   
The carbs were cleaned totally dismantled in an ultrasonic bath.
As mentioned in my previous message I will start just giving some more play at the clutch external lever as it is true that perhaps it was too tight close (not enough play at the handlebar lever), I will check at the road for any improvement, if not I will go again to check the valve timing that I believe it is the easiest next step.
By the way, in case on need, where can I found the shims for the valve adjustment? Is there any equivalence on other bike brands, because if I need to call to Laverda Paradise door I will need the Bank of Spain support!!!!
Thanks again for your help.
OssaF3 (I?aki)
 
Hi Richard,
Yes, a real one (not a modified one from a standard Copa)  :D.
I bought it from a guy who was the spares department responsible at my city Ossa agency.
It is also a quite noisy lady, and smells so well with the Castor Shell oil in the mix. Clearly not the bike to be in the city between 50 mts each traffic lights.
Regards,
OssaF3 (I?aki)
 
Hi,
I have no photos of this bike as I am not very fan of making photos, but if in the coming weeks I have the bike out of the shed I will try to post some.
I never raced this bike, in my area this kind of bikes were always too expensive to be raced because the only meetings were what we call "Subidas en cuesta" (Hill sprints), I used it as a practising bike to get learn the road in the previous days to the meeting, but my racing bike was a Bultaco Pursang MK 10 modified to this type of racing, the problem was that the practising bike was much faster than the racing bike!!!
Returning back to my Alpino problem issue, yesterday I tried after giving more play to the clutch but, unfortunately, there was no improvement.
I made a test that perhaps could give to any of you a clue about the origin of the problem, the test was to open very rapidly the gas from the medium point when in fact there was no more acceleration in a down hill road, the exhaust sounded very deep making a sound similar to a rebound with some misfires, turning down the gas the sound returned to normal immediately, but the speed was still the same 120 km/hr.

This week, if a can find some time after work, I will check the valve timing.
A friend from this forum has offered me some shims from a triple in case I need to adjust the valves, do you know if they can be used for the 500? In case of need, where could I get some?
Regards,
OssaF3 (I?aki)
 
Initially thoughts when I read,was one of over fuelling,but you've checked main jets.
Check valve clearance and cam timing.What type of exhurst is fitted,have the internals collapsed within the baffle restricting the flow of gases?

Andy
 
ossaf3 said:
This week, if a can find some time after work, I will check the valve timing.
A friend from this forum has offered me some shims from a triple in case I need to adjust the valves, do you know if they can be used for the 500? In case of need, where could I get some?
Regards,
OssaF3 (I?aki)
Click to expand...

no, shims are different from the 500's (6mm valve stems) and the triples (7mm valve stems)
 
Hi friends,
I am quite frustrated after having adjusted once again the valve timing and also checking the valve adjustment (that it is not perfect because I had not correct shims to change, but I have placed the closest in size once on each place).
The problem remains, with no changes at all.
A doubt, I have adjusted the timing following the workshop manual, with the camshaft gear wheel aligned on the marks, being sure that the piston was at TDC, also the mark at the rotor, etc,..., but I have seen that to reach the perfect alignment of the wheels it was necessary to force the wheel to act on the exhaust camshaft (from camshaft repose, around 6-7 mm to align the exhaust camshaft gear with the central bearing cap mark.)
Sounds this to you normal?
Where could I obtain valve shims of different thickness?
Is there any equivalence, or similar ones that could be purchased more easily from any Jap bike?
I am very frustrated with the bike,...., please give me any extra idea about what to check now.

Regards,

I?aki (OssaF3)
 
Shims in all sizes available from OCT in Germany

oct@gmx.de

One camshaft is always in tension at TDC.

Have you checked ignition timing?  Does ignition advance work?  If the stock system is still fitted, advance step should happen at 1800-2200rpm.

piet
 
Hi Piet,
Sorry for the silly question, is there any easy way to check if the advance works or not?

Regards,
I?aki (OssaF3)
 
ossaf3 said:
Hi Piet,
Sorry for the silly question, is there any easy way to check if the advance works or not?

Regards,
I?aki (OssaF3)
Click to expand...

Sorry for the frank answer, but I really think you should take the bike to somebody that knows what he's doing.

As it seems, you will be poking around in the dark for quite some time to come, heaven knows what other damage you may inflict on the bike, only making matters worse.

When attempting to help people like yourself on a platform like this, one assumes that the person inquiring knows at least a couple of basics regarding whatever he/she is trying to tackle.  If this basic knowledge isn't present, all involved turn around in circles for ages, getting nowhere...

piet
 
Thanks Piet,
To be sincere your answer hurts a little my selfconfidence but I am sure in the medium and long term it will be more usefull than expected.
I will try to put the bike in the hands of someone with enough knowledge, not knowing who now but after some research I will find someone around my town.
Meanwhile I will keep reading the articles of the forum as I am sure will help me to know more about these bikes.
Thanks again for your words, help, patience and frankness (for sure better than nice words and a hole in the piston!).

Regards,
I?aki (OssaF3)

 
Stick with us Inaki, we are grumpy old men remember  :D
Good luck with your bike!
 
You must log in or register to reply here.
Back
Top