New K750M (Or something made to look like one) owner

[Redtrev]

Hello all.
Recently bought what I was told was a K750M 1967 with some problems here in the UK. More fun than a 12 year old with a Meccano set.

No. 1 Cardan rubber interferes with the frame. It is rubbing against the edge of the hole for the cardan shaft. Is this the right gearbox for this frame? Spacers on the engine mount look correct but the cardan shaft looks off centre to the hole.

No. 2 Stripped the gearbox. First gear and well as the 24 tooth and 32 tooth gears look part stripped on the smaller gear part. Only first gears I can find are 37 tooth and mine is 36 tooth. Any ideas or should I go for the 37 tooth.

No. 3 Is it a K750M or MT12 or Mickey Mouse Special?

Thanks in anticipation.

[dneprlover]

It is a K750 based mongrel with a short frame. year is about right. Don't think it's an 'M' model. Shouldn't have an MT304 gearbox reverse gearbox (about 20mm longer in total than the original) but if you are using it as a solo, I have some complete MT804 gearboxes without reverse from MT9 factory solo machines. Plenty of spares for all the different types as well.

Mismatched wheels, TLS brake, later rear drive, Most bits will interchange so no surprises there.

What are the part numbers for the gears you need?

[Redtrev]

I have a spare gearbox I might try.

[dneprlover]

That is the correct non reversing gearbox for the bike but you might need a longer cardan shaft.

[Mr Wazzock]

Question from the back of the class (puts hand up) – what does the lever do that looks like a reverse lever, but obviously isn't?

[dneprlover]

Hand change lever, often referred to as a 'Neutral finder' Same as all Ural models up to the M8-103 models. Dnepr's had reverse 15 years before Ural did. Dnepr introduced the MT804 reverse gearbox in 1972 on the MT9

[Redtrev]

Many thanks. I shall put that one in and see where we go from there.

[rivers]

Can't help with model ID or the issues you're having. I'm an old flathead lover and think that's a beauty! I'd just fix what's needed and then ride the wheels off it!

[sKiZo]

The white grips are what sold me on it ... <G>

DO pay attention to all the rubber on something that old, especially if it's been sitting. I picked up on an older machine
several years back - stock rubber on it, and it looked good. 100 miles later, sidewalls were cracked all to hell and looking to blow.

[Scott]

Ditto everything Dneprlover said.
It's an early 1958 - 1962-ish short frame K-750 (or maybe a military K-750B I think it was called?) with the wrong front forks, engine, gearbox, non-original tank, etc.
K-750M's are the most common K-750's and have a longer frame that would accommodate your longer gearbox.

I have the same situation going on as you, but the metal around the hole where the rubber donut passes through has been shaved to the point it's not an issue.
Good luck if you ever need to take out the engine or gearbox.
DAMHIK...

[dneprlover]

K-750M's are the most common K-750's and have a longer frame that would accommodate your longer gearbox.

Nope. ALL K750 had short frame. Long frame came out with the introduction of the MT9/MT804 in !971-72. Any flathead with a long frame is an MT12 using the frame from the MT10.
K750m came out about 1964 with the ending of the short leading link forks. They are most common because of the longer production period (1964-1977 ish)

[Scott]

K-750M's are the most common K-750's and have a longer frame that would accommodate your longer gearbox.

Nope. ALL K750 had short frame. Long frame came out with the introduction of the MT9/MT804 in !971-72. Any flathead with a long frame is an MT12 using the frame from the MT10.
K750m came out about 1964 with the ending of the short leading link forks. They are most common because of the longer production period (1964-1977 ish)

I'm pretty certain that the original K-750 with the leading link suspension were short frame.
The frame was lengthened on later K-750's (technically K-750M) with telescopic forks which is the most common K-750.

Photos here:
http://www.sovietsteeds.com/galleries/t ... =12&page=4

[dneprlover]

Pointless showing a frame with a ruler next to it and saying started 1960-61. Note the gearbox. That's an MT804 which wasn't produced Until 1972.
Short leading links were dropped 1963-64

The photo of the bike used to illustrate your argument is actually a later MT12. Why lengthen the frame when there is no need? the need came when the MT9 was introduced in 1972. In the interests of standardisation and using up surplus stocks, Dnepr continued with the old frames and gearboxes until production of the K750 ceased about 1976-77. Engines were used up by creating the MT12 model ( SV motor with MT10-36 frame and drive system.)

The K650 models introduced in 1966, still had short frames and the original model gearboxes and continued production in that form until 1971-72. They used all K750 parts apart from the OHV motor and 12v electrics