33mm smoothbores

[Anonymous]

anyone here think (or know) if 33's are too big for a stock gs1000 motor with a pipe and k&N's. i've heard diff. viewpoints on maybe being too much for a stock motor due to inlets originally being matched for 26's.
thanks. great site-lots of very good info.

[Hoomgar]

I was told that if you port the head for better flow that the 33 smoothies are the desired carbs for the 1000 by a respectable vintage bike engine re builder. But while doing my own GS1000 project we found that just as you said the head that fit the 26mm carbs on my 78 had very small intake openings and we ended up switching the head and block to that of one from an 80 GS1000L model because it came stock with 34mm carbs and the intake ports were much larger. The intake carb boots were not interchangeable either as the mounting hole patterns do not line up.

I am going with the 34mmcv carbs of the same bike we got the head and block from but would now be able to use the 33 smoothies as well if I had a set.

I am not 100% sure that the info I just gave you applies to all year/model GS1000's but did for sure between the ones I mentioned. hope that helps.

You can see more about what I was saying by clicking on the project link in my signature quote.

[robinjo]

[off-topic]

Say Hoomgar can't you atleast make it a nice link like this My kick@$$ GS1000E project

[/off-topic]

The info Mark provided sounds right, the '80 and on 1000's had the big port head.

[Hoomgar]

[off-topic]

Say Hoomgar can't you atleast make it a nice link like this My kick@$$ GS1000E project

[/off-topic]

The info Mark provided sounds right, the '80 and on 1000's had the big port head.

There, hows that?

[robinjo]

[off-topic]

Say Hoomgar can't you atleast make it a nice link like this My kick@$$ GS1000E project

[/off-topic]

The info Mark provided sounds right, the '80 and on 1000's had the big port head.

There, hows that?

[Anonymous]

33mm smoothbores/80 1000 g/L

not knowing anything about the 80'models- will a 80 g or L block and head bolt right onto my 78 cases with no mods? can i just bolt on the head or is the head bolt pattern different?
after all that maybe i should just port the head and call it a day!!!!???



78& 79 GS1000E.

[Hoomgar]

The block and head will bolt right onto your 78 case yes. The head bolt pattern is different so you will need both, you can't just bolt the 80 head onto the 78 block no.

If you look at this picture you can see the bolt pattern. One main difference is the bolt I circled in red.

[Anonymous]

Is that 1 bolt hole the only difference.

[Hoomgar]

Is that 1 bolt hole the only difference.

I think it is but others on here have commented to the fact that the bolt pattern is not the same. You can't interchange them though even if it is just that one bolt. You need that.

[Anonymous]

Thanks HOOMGAR.I think I'll wait for an 1100 engine. I miss the grunt.

[Anonymous]

33mm smoothbores/80 1000 g/L

guess i'm a traditionalist amongst you gs fanatics. (respectfully stated)
i prefer the look of the gs1000 motor so its off to the head port guy i guess. sorry i sold a set of RC cams on this site.
great site-tons of great info.

[Anonymous]

you might try to find a set of 29mm smoothies instead of the 33's. The 33's will fit on old style of heads with the boot adapter mikuni used to sell. But without some major mods you will find that the 33's are almost impossible to dial in as you don't use the full potential of the larger carbs and as such have to reduce the jets and change the slides. With the 29's there is a lot less hassle dialing in for low range and mid range.

Hey hoomgar whats that STUFF in cylinder #4?? 8O 8O Trying to reduce the volume of your cylinder? Volumetric efficiency?

[Hoomgar]

you might try to find a set of 29mm smoothies instead of the 33's. The 33's will fit on old style of heads with the boot adapter mikuni used to sell. But without some major mods you will find that the 33's are almost impossible to dial in as you don't use the full potential of the larger carbs and as such have to reduce the jets and change the slides. With the 29's there is a lot less hassle dialing in for low range and mid range.

Hey hoomgar whats that STUFF in cylinder #4?? 8O 8O Trying to reduce the volume of your cylinder? Volumetric efficiency?

ehhh, that sh!t will buff out


LOL

[KEITH KRAUSE]

I've also heard the 29's are a better choice than the 33's.
Motorcyclist Magazine built a '79 GS1000 in '84 (no porting work) and their opinion was "the 33's are too big for the stock ports and are too sensitive to sudden throttle openings at low rpm. The 29's respond wonderfully to throttle commands". As I said, the ports were stock. Their other mod's were a 1085 kit, 106 degree cam timing, K&N's and a V&H megaphone. The 33's may be justified with porting, but be prepared for tuning difficulties.

[Hoomgar]

Same here Keith. I was told that for the early 1000's like our that the 29's are actually better than the 33's since you wont use up the 33's anyway.