750 GT Coming out of storage

Bern · Post by **Bern** » Wed Jul 07, 2010 4:47 am

So I have a 750 GT that has been in a collection and idle for 12 years. I am going to be doing some riding on it nothing too intense but I want to make sure I don't miss anything when getting it ready for the street.

I am likely going to replace the seals on all of the shocks.
Rebuild the brake calipers.
The carbs have been cleaned.
It has an electronic ignition now so no need to clean the points.

What other maintenance is a must?

Post by **BevHevSteve** » Wed Jul 07, 2010 6:25 am

Lube all cables, speedo drive, s/arm pivot, headset
clean all electrical connections
replace tires, tubes, rim strips
change out fork fluid and seals
change out intake manifold insulators

plus check everything

Steve Foster · Post by **Steve Foster** » Wed Jul 07, 2010 9:15 pm

Bern - engine oil hasn't had a mention. I'd recommend a drain and replace before starting (you won't get it all out if it hasn't been run) and then a change again immediately after the first run.

I'd also take out the plugs, give the bores a light spray of WD-40 or other light spray oil and kick it over a good number of times. This will also circulate some oil around the engine before start up. It might be worthwhile before sparying the oil into the bores to get a flashlight and take look in each cylinder to verify that there is no debris or any build-up of rust.

Fit new plugs and check and clean them after the first run.

The battery will probably need replacing even if it has been on a charger and holds a surface charge for a while.

Might be worth replacing the fuel hoses as they could be brittle and may leak at the clamps or along their length - at the very least have a good look after turning the taps on and before starting.

Hope it all goes well.

Cheers,
Steve.

Bern · Post by **Bern** » Thu Jul 08, 2010 2:59 am

Thanks Steves,

The oil has definitely been done, a new battery , new plugs but definitely not the right ones. I think they are too cool for the 34 degree weather we are having at the moment.

I did notice the intake manifold insulators are a little cracked. A number of the grommets are in need of replacement as well.

Looks like I'll have a weekend of puttering and playing

Steve Foster · Post by **Steve Foster** » Thu Jul 08, 2010 6:29 am

new plugs but definitely not the right ones. I think they are too cool for the 34 degree weather we are having at the moment.

Bern - the matter of spark plug heat range and ambient temperatures is an interesting one. I used to think that, all other factors being equal, hotter ambient temps meant that a cooler plug was required, and vice-versa. But things aren't as simple as that (are they ever??). In fact, the opposite could well be the case.

As an example: as the air temperature decreases, its density increases, requiring more fuel per volume of air to maintain the correct mixture. If the mixture is not properly richened (and I don't know too many people who bother to retune their carbs on a seasonal basis), and the mixture is too lean, higher cylinder temperatures, and a subsequent increase in the spark plug tip temperature can result. Hence, a cooler plug might actually be required.

I guess that the best thing to do is to look at the plugs to see whether there are any signs of them not operating in their correct heat range, while being aware that their operating temperature depends on many variables such driving habits, traffic, fuel quality, altitude and ignition timing, as well as the weather.

Steve.

Bern · Post by **Bern** » Mon Jul 12, 2010 5:29 am

Hi Steve,

What plugs are you running?

Thanks

Steve Foster · Post by **Steve Foster** » Mon Jul 12, 2010 6:23 am

Hi Bern - check out the "Iridium Spark Plugs - 900 GTS" thread in the "Electrical and Wiring Shop" section. Also, give the forum's Search feature a try to find other posts relating to spark plugs.

Take a look at Gordon Jennings' classic article "How you can read spark plugs and select them" at http://www.strappe.com/plugs.html. There's a very important concept here: "We must emphasize that it is the engine that puts heat into the plug, and not the reverse. A 'hot' plug does not make an engine run hotter; neither does a 'cold' plug make if run cooler."

Steve.

Bern · Post by **Bern** » Mon Jul 12, 2010 6:30 am

Super quick response. Thanks!!!

I did read those and I think I will use NGK BP7HS plugs but I was curious what other people were running.

Thanks

Chris Bushell · Post by **Chris Bushell** » Tue Jul 13, 2010 8:35 am

Now the interesting thing is that my 750 runs standard length plugs, not extended point ones. I think you may find that extended point ones hit the pistons.

Sorry I should have said that I have been running B7HS plugs quite happily.

Chris

Bern · Post by **Bern** » Tue Jul 13, 2010 9:41 am

What do you consider to be standard length?

http://www.ngksparkplugs.com/docs/tech/ ... _plugs.pdf

Post by **BevHevSteve** » Tue Jul 13, 2010 10:24 am

Chris Bushell wrote: Now the interesting thing is that my 750 runs standard length plugs, not extended point ones. I think you may find that extended point ones hit the pistons.

This is a confusing statement to make without stating plug model numbers of what you are referring to. Please clarify by stating specifically what you are using and what you are warning to not use.

That said, these are all good choices for bevel drives
http://shop.bevelheaven.com/SearchResul ... ords=spark

wdietz186 · Post by **wdietz186** » Tue Jul 13, 2010 7:10 pm

With stock or Sport pistons the extended tip plugsBP6HS or BP7HS will work fine and won't hit the pistons.In my 750GT with Sport pistons I've been running BP6HS for years. The important thing is a good ignition system and a strong battery,neither of those are standard on a 750.

machten · Post by **machten** » Sat Jul 17, 2010 10:11 am

Yep, what wdietz186 said plus 1. You can use BnHS or BPnHS (the extended points) with no issue regarding contact even on high compression sport and SS pistons.

Regarding the "n"...

where n=7 (standard heat range from original spec) or n=6 - slightly hotter - often used for a higher burn temp when using valve lubricant. My understanding is that the B7HS is closest to the original spec for roundcase - I use them in my 750 Sport with hardened valve seats (no valve lubricant), - I use B6HS in my 750 GT with bronze valve seats (valve lubricant), I use BP6HS in my squarecases with bronze seats with valve lubricant. It seems to work fine. Why do I do it that way? Because a good bevel mechanic told me to some years back. Is it the right thing to do??? Dunno!!! - But it works for me, so I've done it that way since leaded was outlawed in Aus some 10 or so years ago.

Clearly "n" must also be influenced by the ambient temperatures of your environment - so you woundn't run a "6" in a Dubai summer, for example.

Kev