A few questions about this 450.

[robinjo]

This is the bike, it belongs to a co-worker who says it's a '88 but he doesn't have the papers yet, is this the correct year? the frame number = GL51C-104246

So I need some settings like the float height, model spark plugs and maybe valve clearance, assuming it has shim adjusted valves going by the round covers on the head? :? Is 120 the stock size main jet?

Any help would be greatly appreciated as usual

[Hoomgar]

What year is stamped on the tail light?

[robinjo]

What year is stamped on the tail light?

Well there are lots of different numbers on there but no year, I did find '87' stamped on the wheel and '1|2'.

[Hoomgar]

You could call a dealership robinjo and give them the vin. They will tell you for sure. I do that a lot, they love me

[robinjo]

The front tire, a lovely Bridgestone Mag Mopus :? , is made in the second week of ?8, should I advise him to change it?

[robinjo]

RIGHT, lots of work done on the old girl...

cleaned the carbs thoroughly
set the float heights to 22.4 mm as found in some threads about 450's
new gas
new engine oil
new spark plugs NGK B8ES according to the bike shops little book
cleaned and oiled the air filter
replaced brake fluid
lubed and adjusted the clutch cable

and some other minor stuff like putting the blinker that fell off back on and some small lights replaced.

Now the bike starts perfect and idles very nice but as you ride it, after a few miles it starts to "stutter" when cruising and accelerating when it gets warm, sort if feels like a coil losing it but still idles beautifully :?

would this be mixture-related or elecrical

[earlfor]

It sounds like it would be mixture related. Also, in the photo, the header pipes are dark blue. The mixture is too lean or at least at the lean limit.
I suspect increasing the vacuum levels in the carb synchronization will solve the problem. Raising the fuel level in the float bowls would also help.

Earl

Now the bike starts perfect and idles very nice but as you ride it, after a few miles it starts to "stutter" when cruising and accelerating when it gets warm, sort if feels like a coil losing it but still idles beautifully :?

would this be mixture-related or elecrical

[robinjo]

It sounds like it would be mixture related. Also, in the photo, the header pipes are dark blue. The mixture is too lean or at least at the lean limit.
I suspect increasing the vacuum levels in the carb synchronization will solve the problem. Raising the fuel level in the float bowls would also help.

Earl

Now the bike starts perfect and idles very nice but as you ride it, after a few miles it starts to "stutter" when cruising and accelerating when it gets warm, sort if feels like a coil losing it but still idles beautifully :?

would this be mixture-related or elecrical

My first susp iscion was also too lean a mixture but I thought it should be worse when cold???This is a pic of the new sparkplugs after a 30 mile testride, I now also think it's running a bit lean. [img]http://nl.msnusers.com/_Secure/0QgAAAAcUoaC0dxmarm2P*fI0cIk6O0WVtNW3Hx5BvZhygwvnz Cd*OTItbMZ1!Rvv41dc3VyfjPk8SMELtO14DJnTkEEZP1hBGgA PfpoSiY0/bougies.JPG?dc=4675466534561627883[/img]

Earl you say increase the vacuum levels or raise the float height, can I just put the needle clip one notch lower (and so raise the needle itself) to get the same effect or does that work out differently? I don't have synchronising tools now.

[Anonymous]

How do you raise the vacuum levels? When I worked on mine it only had 1 butterfly adjustment so I set the left to the same height as the right.

Cheers, Steve

[earlfor]

Yes, lowering the needle clip should work........assuming the lean condition occurs when the rpm is in the range that the needles are active.

If the lean condition is slight, setting the air gaps on the throttle plates is an easy fix. However, considering how lean your plugs are showing, I would probably choose your approach.

Earl

Earl you say increase the vacuum levels or raise the float height, can I just put the needle clip one notch lower (and so raise the needle itself) to get the same effect or does that work out differently? I don't have synchronising tools now.

[earlfor]

Closing the butterfly will increase vacuum. You can modify the vacuum level on 2 with the idle adjustment knob, then match 1 to it. To change engine idle rpm, adjust mixture. (keep in mind we are talking about fine adjustment/tuning and that major vacuum level changes and mixture compensation is not possible with the range of adjustments available.)

Earl

How do you raise the vacuum levels? When I worked on mine it only had 1 butterfly adjustment so I set the left to the same height as the right.

Cheers, Steve

[robinjo]

Yes, lowering the needle clip should work........assuming the lean condition occurs when the rpm is in the range that the needles are active.

If the lean condition is slight, setting the air gaps on the throttle plates is an easy fix. However, considering how lean your plugs are showing, I would probably choose your approach.

Earl

Earl you say increase the vacuum levels or raise the float height, can I just put the needle clip one notch lower (and so raise the needle itself) to get the same effect or does that work out differently? I don't have synchronising tools now.

Right I will lower the needle one notch and take another test ride tomorrow. I just hope it can be done without taking the carbs off again

[earlfor]

At least you have only two carbs to remove. Besides, skinned and cut fingers improves character and vocabulary. :-) :-)

Earl

Right I will lower the needle one notch and take another test ride tomorrow. I just hope it can be done without taking the carbs off again

[robinjo]

Back with the 450, this time with an oil leak, I'm pretty sure it comes from the seal around the output shaft (see pic)

[img]http://nl.msnusers.com/_Secure/0QwAAABITmGnfCBpckcl0rnoskk1lQB2YowKaBOTlF2VJMonPY O9ZR8zbzcS*hC0VaCXUpCwJJlULqoV36gqAzPupVl0nyFC!bGq Zp5KjK!M/HPIM0388.JPG?dc=4675468610349900617[/img]

Am I correct to think it can be replaced from the outside? In normal condition there is a metal plate over the clutch pushrod and output shaft held there bu 2 bolts, removed in the picture, bolt holes clearly visible. Any problems that can occur when replacing the seal? I'm hoping it is still available at the Suzuki dealer...

[Anonymous]

How did this work out? Were you able to fix the leak? I have an older 450 that has this problem.

Thanks!